M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Engine + Driveline => Topic started by: bmwman91 on November 03, 2019, 08:28:21 PM
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This will be my project log + my questions thread that I document as I sort things out. It may well be a couple of months from now until it's finished.
It looks like it is time for more M42 wrenching. Other than replacing the crank damper wheel and some miscellaneous stuff around there earlier in the year, I have not had to touch this engine since ~2013. Some of you will recall that I had Metric Mechanic build me a 2.1L stroker, which at the time had a couple of valve spring failures, so I had the head off and replaced the HG back then. Maybe I messed something up then, or maybe when the crank damper was coming apart and the timing was way off some of the resulting detonations damaged it, or maybe it is just the result of me driving the living shit out of it lol. Whatever the case, I am 95% sure that the HG is toast between cylinders 2 & 3.
I got a loaner compression test set from the local parts store and saw:
Cyl 1: 70 PSI
Cyl 2: 0 PSI
Cyl 3: 0 PSI
Cyl 4: 50 PSI
This was on a luke-warm engine with a loaner gauge that was probably abused, so I am not really super concerned about #1 and #4. The fitting for the spark plug holes could only be tightened down onto the o-ring with the hose coming off of it, so there was probably just a ton of leakage. Anyway, given that two adjacent cylinders have no compression and I can basically hear air exchanging between them if I put the shop vac onto one spark plug hole, I am assuming that the web in the HG between these went out. I was maybe a mile from home on the expressway when I noticed that the car would not make more power when I got onto the throttle, and I thought that I heard some pinging or other not-good noise for a few seconds before it just kind of ran poorly. I got it home and it certainly seemed to not be running on all cylinders, as well as intake+exhaust notes which sounded like air moving to wrong places at the wrong times. My very first thought was that I got bad gas since this all started about 2 minutes after refueling.
As far as I can tell, the oil is not milky. It's pretty clean since I just changed it 1500 miles ago, which at first made me think it was contaminated, but I think I was just being paranoid. Also, the coolant level in the expansion tank was not altered, so exhaust products don't seem to be making their way into the cooling system. Anyway, how long do you usually find that it takes to turn the oil noticeably milky when a HG is going? I suppose it varies depending on the severity. If I am having this hard a time telling, then either no coolant got in, or I caught it early. I'll drain the oil anyway just to make sure later on in this project.
The M42 HG is pretty straightforward to swap, assuming it is the only casualty there. I am going to have the head milled, but I am also going to check with MM about some newer cams. Apparently a few years after my build, they came up with a new cam profile which boosts top end power 10-15HP, with minimal loss in the mid-range. Maybe I will send them the head for a little refresh and new cams while I am at it. If not, then I will just do it locally since there are competent head machining shops in the area. Decisions, decisions.
So far, here is a list of what all I am replacing as part of the project:
Head Gasket (OEM metal M44, probably)
Head bolts
Inner profile gasket
Outer profile gasket
Upper timing case cover gasket set
Thermostat housing gasket
Thermostat o-ring
TB gaskets
Lower intake manifold gasket
Upper intake manifold gasket
Exhaust manifold gaskets (head and cat pipe)
Rubber exhaust hangers
Engine-to-chassis ground strap
Alternator-to-engine ground strap
Hood-to-chassis ground strap
Spark plugs (all)
Ignition coils (all)
Is there anything else I am forgetting? Earlier in the year I did the water pump, thermostat, alternator bushings, belts, VC gasket, coolant temp senders (both), cam & crank position sensors and crank damper.
Other thoughts/questions:
I recently picked up a 2006 Jetta TDI, which has been my DD. So the E30 has been getting driven a LOT less, like once every 2 weeks. This makes it a little tougher to diagnose recent symptoms since I have not been driving the E30 much.
I am curious about whether some of my mysterious intermittent poor running is maybe from this thing being partially failed for several months? The car has been acting weird in that about 60 seconds after a cold start, it has trouble idling for maybe 5-10 seconds, and then it goes away after blipping the throttle a couple of times. The ICV is clean, so I am pretty sure it is not that. Could the HG have been leaking a little between #2 & #3 for a while, and it just now fully blew out? It's been doing this for maybe the last 5000-7000 miles, slowly getting worse. I have probably replaced every sensor on the car, and none of it completely fixed the issue.
The last couple of times I drove it, it seemed to be a little hard to start as well. Other than that, it has been running strong all the way up to 7500RPM.
The ICV is making an audible clicking/whirring noise when the car is parked in accessory-II mode. I don't ever recall noticing that before. The tone seems to change if I push on it / move it around. Is this a sign of a dying one?
Here are some shots of the spark plugs that I took today when doing the compression test. These are maybe 15K miles old, and have been through a LOT of fuel/ignition tuning. Do you agree that they mostly look like they have been through some rich running, and hard driving, but nothing much else obvious?
#1
(http://www.e30tuner.com/assist/m42hg2019/splugno1.jpg)
#2
(http://www.e30tuner.com/assist/m42hg2019/splugno2.jpg)
#3
(http://www.e30tuner.com/assist/m42hg2019/splugno3.jpg)
#4
(http://www.e30tuner.com/assist/m42hg2019/splugno4.jpg)
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I got a little bit of prep done after work today. Mainly, I wanted to completely drain the coolant using the block drain so that there would be an absolute minimum of coolant left in the head. It makes a bit of a mess when you pull it off! I am being extra careful because the repair will be done in my garage, where my cats have access. Coolant is EXTREMELY toxic to cats, who like its taste and smell, and it causes an agonizing death. Anyway, I carefully drained it from the radiator first, and then got the rest out from the block drain using a funnel with a hose under the outlet. There was minimal spillage from there, and I just rolled the car back out into the driveway to hose things down. It'll sit there to dry for a day or two since I have limited time during the week, and it gets dark earlier now with the time change and all (I do not like Daylight Savings Time). I am sure my neighbors are used to seeing me manually pushing the car around in the driveway by now lol.
As a part of getting the funnel under the block drain, I removed the exhaust header. It is super easy to do if you remove the right side engine mount arm (support the engine with a jack). It slides right out the front...as long as you do NOT have A/C installed. If you do have A/C, then you either need to remove the compressor, or the sway bar (and even then I am not sure if it would go out the back).
The coolant did not quite look right. I'd say that combustion gases were definitely making their way into places that they did not belong. This coolant is less than a thousand miles old!
(http://www.e30tuner.com/assist/m42hg2019/bmw001.jpg)
(http://www.e30tuner.com/assist/m42hg2019/bmw002.jpg)
A good amount of debris came out with it, after using the block drain. The dark stuff was almost all magnetic, and I am guessing that this is burned head gasket material.
(http://www.e30tuner.com/assist/m42hg2019/bmw003.jpg)
(http://www.e30tuner.com/assist/m42hg2019/bmw004.jpg)
(http://www.e30tuner.com/assist/m42hg2019/bmw006.jpg)
There was also this bit of paper material in there. I'd guess that it is not from this failure since it does not look burned. Maybe it is just crap from a past gasket that I scraped.
(http://www.e30tuner.com/assist/m42hg2019/bmw005.jpg)
There was a little bit of an indication of trouble (maybe) at cylinder #3's exhaust port. I am guessing that some of the large detonations that occurred in the exhaust when the crank damper was failing had damaged the gasket. It would explain why I thought that the car was making more exhaust noise than usual.
(http://www.e30tuner.com/assist/m42hg2019/bmw007.jpg)
That is it for today. Next steps in the immediate future will be to re-run a compression test after re-charging the battery fully, and using a better compression test kit. It irks me a little than cylinders 1 & 4 were reading low with the loaner compression gauge, and I can't imagine that all four cylinders went out together. Besides, if they were totally shot, I wouldn't think that the engine would run on 2 cylinders at all, let alone enough to get me the last mile home. After the compression test, I will start stripping the rest of the stuff off of the head in preparation for its removal.
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Lets hope it's the gauge. Hit up the pawn shops for a good used compression tester. Most new affordable tools are made in China.
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It may also be that the oil got washed off of the cylinder walls. I managed to get the car started a couple of times immediately after the initial failure when I was checking stuff in the driveway, but it involved a lot of cranking, so I think that a lot of fuel was passed through the engine without combusting. I will try squirting a little oil into cylinders 1 & 4 to see if that helps to reinstate the seal.
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I got a look into the cylinders with the borescope this afternoon. I noted multiple HG failures, and I assume that cylinder 3 was the source of the problem. Both cylinders 2 & 4 showed HG ruptures protruding into them, so there must have been a heck of a misfire in #3 at some point. Back when the crank damper went out, I was driving through my neighborhood under light load. The misfires occurred when limping it the last quarter mile home and while troubleshooting in the driveway, so no high RPM operation was occurring at the time. That makes me think that I may have made a mistake (or multiple) when installing the HG in 2013, and that whatever flaws there were in the assembly were made worse by the low-load detonations and then it finally gave up the ghost this last weekend. I'd bet that the inter-cylinder leaks have been there for a while as pin-holes, which would partially explain the bad gas mileage. My increasingly-poor idle and increase in engine/exhaust noise over the last few months could have been the leaks opening up further. Considering none of the external visual and electrical tests I did at any point came up with a cause, this seems plausible as a root cause.
Here are borescope shots of everything. I don't see any immediately obvious indications of trouble beyond the multiple HG failure sites. Despite my best efforts to vacuum all debris out and away from the plug holes, crap still made its way in, so I am not bothering with any compression tests and just going straight to pulling the head. Turning the crank with a wrench also aligns with what I can see. Cylinder 1 has the expected compression/resistance, cylinder 4 has a little resistance and there is none from 2 & 3. Basically, I am sort of surprised that it was running at all.
Now that I look closer, #1 might have also been leaking with #2. Not enough to rupture, but there is a suspicious amount of carbon buildup. Anyway, the period of time in 2013 when I did the HG was not a good point in life on multiple fronts, and I was ready to sell the E30 just to be rid of it. I was stressed, sleep deprived and rushing the repair despite it being my first time doing it. If I really did that poor of a job, then I am glad it failed enough to be obvious so that I can take my time and do it properly this time. I almost don't want to post these pictures because it's embarrassing to believe that I may have done it so poorly!
Cylinder 1
(http://www.e30tuner.com/assist/m42hg2019/borescopecyl1.jpg)
Cylinder 2
(http://www.e30tuner.com/assist/m42hg2019/borescopecyl2.jpg)
Cylinder 3
(http://www.e30tuner.com/assist/m42hg2019/borescopecyl3.jpg)
Cylinder 4
(http://www.e30tuner.com/assist/m42hg2019/borescopecyl4.jpg)
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So Jim from MM called me earlier. I guess it bugged him that the engine is out on its ass again. Despite repeated mechanical issues with the expensive product I purchased, I have maintained a good working relationship with them. I expressed to Jim that I don't really feel like I ever ended up with the product I paid for, even if the last HG install involved my own errors, and MM would like to try to make things right for good.
The short story is that I am pulling the engine and shipping it out to them. They'll tear it down, and I'll make the call about what to do or not from there. They aren't doing it for free, but it is at a reduced cost that I think is fair. This is somewhat of a "lazy" solution, but I just don't have sufficient time and energy to deal with this correctly myself right now. If MM was not willing to work out a deal then I might feel more motivated since I dislike the idea of throwing money at things, but they seem willing to stand behind their product.
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Nice of them to stand behind a ~6 year old engine with how many miles?
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I have put something like 40k miles on it. Yes, I am impressed that they are willing to help me out, granted it is not free, but to offer to do it for a reduced cost is cool.
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My gut tells me the damper issue started it. Did you install a M42 or M44 headgasket?
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It was an M44 HG, the +0.3mm one since the head had been machined multiple times by then.
Yeah, the failed crank damper had something to do with the failure for sure. I got some pretty big detonations when it was coming apart and the ECU lost proper track of timing.
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Hey there, any updates?
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Hey, yes! I have been posting mostly on r3v and there is too much to cross post at this point. Post 31 in that thread (link below) is where I guess things diverge from here, although the actual substantial updates start at post 55.
Basically, I have the engine in my garage, all of the parts I need should FINALLY be showing up next week, and I have totally overhauled both the engine wire harness and the whole front chassis wire harness. There is still a little repair work to do on a couple of things (replacing decayed connectors and the crumbly front pad wear sensor cable), and some other minor stuff to address while the engine is out, but I am otherwise ready to get this thing together and running.
https://www.r3vlimited.com/board/forum/e30-technical-forums/engine-drivetrain/m42/9882794-m42-head-gasket-blown-project-thread
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Good to hear. Just went through it all there. I will keep looking there.
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Although I am most actively updating over on r3v, I would like to make sure that I share some stuff. For one, I made a full color wiring diagram for the engine harness. See the PDF link for that.
http://www.e30tuner.com/assist/m42wireharness/EngineHarness_M42B18_E30_318iS_OEM.pdf
Also, I am going to be up and running soon. Again, all of the long and boring details are on r3v along with many photos of all the other stuff I have done while waiting for parts, but at this point it is fully reassembled and in the car. I was going to be running a week ago, but all 4 fuel injectors are stuck shut since they sat for 3-4 months after being cleaned. It is apparently a fairly common thing to have injectors stick closed if they sit dry for some amount of time. The 250 cc/min ones I had in there worked, but are a little lower flowing than ideal, and I swapped them for some 300 cc/min ones. Sssquid Tuning cleaned and flow matched my old ones, which sat for too long in my garage, and they were kind enough to let me do an exchange for the higher flowing ones which were also cleaned and flow matched. As soon as I get a chance to burn the updated tune, I should be up and running (maybe tomorrow!).
While waiting multiple months for parts, I completely rebuilt the engine harness, and the entire front chassis wire harness (everything forward of the fuse box). All new Tesa tape, replaced any damaged connectors, and new cable straps. It is so nice to have a proper wire bundle up there now with no sticky goo or crumbling tape. I also totally cleaned up the power wiring for my sound system in the trunk, came up with a much cleaner routing arrangement and 3D printed a nice cable management + fuse holder bracket which mounts onto the gas door lock actuator. Again, pics are on r3v which is linked in my previous post.
Speaking of the engine wire harness, I integrated my MAF conversion and wide band O2 controller into it. This is the wiring diagram which represents the harness that I have in the car now. Eventually I plan to go with a stand alone ECU, probably an AEM Infinity 506, at which point I will have to unwrap it all and make even more modifications.
http://www.e30tuner.com/assist/m42wireharness/EngineHarness_MM2100.pdf
Re-taping it will be super easy next time since it will not be 30 years old and sticky, and the new top-of-the-line Tesa engine harness tape uses an acrylic adhesive (not rubber like the old stuff) so it comes off very cleanly. For those that might want to re-do their engine harness, you will want to buy Tesa 51036 tape in 9, 19 and 25mm widths. I do NOT recommend buying it on Amazon or eBay since those places have tons of fake Tesa tape. You should get it from a reputable distributor. One that I can recommend is Waytek Inc (https://www.waytekwire.com/products?pSearch=51036). Also, you will need paper towels and at least 200mL of 99% isopropyl alcohol to clean off the old adhesive goo. It is a lot of work, but you need to clean the old crap off, and it takes 2-4 passes with towels and alcohol. Oh, and wear some rubber gloves...the adhesive does not come off of your skin very easily.
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As always, excellent progress.
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So I got it fired up today. Mechanically, it runs correctly and does not make any odd noises or give any other indication of a major problem. However, it is not currently running correctly. When I started it, it immediately wanted to idle at ~2000RPM. After doing that for a couple of minutes, it would drop to ~1500RPM for a moment, rev back to ~2000RPM and then just keep quickly oscillating like that.
I think that I have ruled-out the AFM (MAF conversion) and TPS since disconnecting those did not really make a difference (the engine would stumble briefly and then resume the previous behavior). I had checked the ICV a month or so ago and it was moving freely when 12V was applied, so I don't think it is stuck open, and I will check again tomorrow. When the engine is revving up to 2000RPM, the AFM output does rise to ~2.25V, which means that metered air is getting in somehow...so it is not a vacuum leak at least. I think that the only sources of a leak like that could be either the ICV, or the TB itself.
Back when I got a spare TB and cleaned it, I used acetone. Some of you may have noticed that the M42 TB (and maybe other engines too?) have a slick gray coating that looks like it was dripped or smeared into the bore. Whatever it is, acetone dissolves it, and when I was done cleaning the TB I could see slivers of light around the perimeter of the throttle plates when I held it up to a light. So, I guess the gray stuff was (maybe?) a sealant intended to produce a zero-clearance fit between the throttle plates and bores. When I noticed the newly created gaps, I wondered if it would be enough to cause enough air to leak by that it might cause issues at idle, but the gap around the perimeter was only ~0.002" (0.05mm) based on checking with some feeler gauges so I figured it would be fine.
I believe that the engine changed from a steady 2000RPM idle to oscillating due to either a switch from open-loop to closed-loop idle control, or some other switch in the software based on coolant temperature. I only ran the engine for 2-3 minutes since I don't want to get it fully warmed up until I am ready to drive it to get the piston rings seated.
Anyway, has anyone else had experiences with leaky throttle bodies? Is a gap that small enough to get the engine to idle at 2000RPM?
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Update. Yeah the TB is a non issue. The one thing that I had assumed could not be the issue, turned out to be the issue lol. It is the ICV.
The car was running fine on it 7 months ago, and I have no idea how sitting for that long could have caused it to die. I did blast it out with brake cleaner, but I doubt that hurt it. Basically, it operates smoothly and does not stick. When I hook it up to my adjustable power supply, the following seems to be the case:
1.7-2V: vane starts to move
3.5V: vane is fully closed
7V: vane is fully open
I am not sure what the normal behavior is supposed to be, but it sort of seems like maybe the return spring is weakened or broken. Either that or there is something going on with the ECU or tune. I got the oscilloscope on the ICV terminals while it was running and the PWM signal is present, so it is not like the signal is stuck ON. I'll try a used ICV to see if that helps, or maybe suck it up and buy a new one.
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I'll have to check out the R3v thread. From what I've read here...you should get some sort of medal or something for your persistence. Keep at it, you've gone further beyond with the NA M42 than anyone...with the possible exception of Warsteiner...you're so very close to the ideal M42!
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Ha, thanks. Yeah I can't believe I am still messing with this thing! Warsteiner was a lot more hands-on with his build, since I farmed out the really specialized work to MM. But, yes, I am hoping that it will be the ideal M42 when it is all done!
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Dude....It's great!! All the work you're doing is totally hands on too. You'll be back up and running perfectly like day 1 in no time flat!
I had fun designing the motor I have....I have slide throttles that I never got to test!! LOL
Cheers,
~Ralph
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OK, I have finally found the cause of my high idle. After replacing the ICV (got one from roguetoaster which was in better shape than my old one) and swapping in a clean throttle body I got a hold of, there was no difference at all. I also tried swapping a spare ECU in to no avail. What DID work was swapping a slightly older revision of my custom tune in. Although it ran rich (old tune was for 24# injectors, current ones are 28#), it did idle at the correct RPM. The latest tune from Sssquid is a little bit "experimental" I think, so they will get me a corrected one soon, since I just emailed them with my findings. It must be that some bytes related to the ICV PWM signal got nuked since it was indeed the case that the ECU was opening it too much (air flow signal should be 1-1.5V at idle normally, and I was seeing 2.25V meaning that too much air was being allowed in to the engine NOT as a vacuum leak).
Anyway, I promise I will get all sorts of pictures up at some point relatively soon lol. I've been busy with work and dicking around with getting this thing running correctly lol.
(the above text is from a r3v post today...the car was idling at 2000RPM and being weird, and it has taken almost a week to determine why!)
Warsteiner, why didn't you get a chance to run the slides? I've always been curious about those. It sounds like they can be a mixed bag, although I would think that if you had the right camming linkage setup and tuning it would drive fine. I am already thinking about an RHD ITB kit haha!
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The damn car still does not run properly. It is perhaps not a software thing after all. I am going to lay out what all I did today and hope that the good folks on here can help me figure this one out, because I am thinking that it is going to be something pretty obscure. Everything is on the table, including faults in the wire harness since I had it totally apart for cleaning & restoration.
- Sssquid sent me a bone stock tune with the only change being what was needed to properly run 28# injectors. The car started and idled properly from a cold start, and I drove it a few miles. About a minute after that cold start, it would stall coming off the throttle (such as at a stop sign) unless I have it a little throttle. The idle would sometimes stabilize if I was careful to really ease off the throttle.
- I swapped out the MAF conversion for the old stock AFM (conversion is plug-n-play) and gave tat a shot with the stock tune. The engine was still fully warmed up. It idled better, did not stall at all, and the only hiccup was a small stumble here and there coming off the throttle.
- After the engine fully cooled off, I started it with the stock tune and AFM to pull it into the garage. It would stall without me giving it a little throttle.
- When the engine was fully warmed up still, I popped in some of the other high performance tunes from Sssquid. They are basically the exact ones that he has developed and successfully run on other 2.1L M42 engines from Metric Mechanic. The car would start and the idle would oscillate between 1100-1600RPM. I did not try driving it, just idling.
- With the engine cold and the performance tunes in, it will idle steadily at ~2100RPM for a minute or two, before starting to oscillate.
I checked the resistance between terminals 43 & 78 on the Motornic plug (the two lines for the coolant temp sensor) and it came out to 400 Ohms when the engine was still luke-warm. Wiggling the wires at the sensor plug did not change the value, so there is no broken wire. I am replacing it anyway since my problems seem to have some link to engine temperature, but it seems unlikely that the sensor is bad since it is only about a year old.
I have replaced or swapped the following items while troubleshooting the oscillating idle to no avail:
- ICV
- throttle body
- TPS
- ECU
- AFM (swapped with MAF conversion)
Sensors & stuff that have been replaced within the last year include:
- Crank position
- Cam position
- Coolant temperature
- Crank damper wheel (60-2 toothed pulley)
Before the HG blew late last year, I was having an issue where the car would stumble and sometimes stall about 1 minute after a cold start, and it would go away after another minute as it continued to warm up. That particular behavior probably started around the beginning of 2019. I assumed it was the tune, but maybe not. I am unsure if it is related to my current issue since the entire wire harness is now a different one, damn near everything has been replaced and/or swapped and I can't think of anything that does not check out properly on my freshly rebuilt engine.
Prior electrical measurements indicate that this is NOT a vacuum leak. First, I have had vacuum leaks before, and they do not make the idle enter a constant oscillation pattern as far as I have ever seen on an E30. Stalling and a stumbling idle, sure, but not the oscillation. Anyway, the air flow signal at idle when it is idling either too high or oscillating is around 2.25V, which means that the ICV is being opened too much. Since I have replaced the ICV, cleaned it very well, checked the wiring connections, and verified that the signal looks about correct with an oscilloscope, I think that there is some issue with one of the inputs to the Motronic which is causing it to purposely open the ICV too much. As far as I know, the only things that are going to have an effect like this on the idle control are the coolant temp sensor, AFM, air temp thermistor and TPS.
At this point, I think that I am just going to have to yank the intake and fuel rail for some inspecting, take apart the big Motronic plug to verify that nothing got yanked when I rewrapped the harness, and probe through every connection from the Motronic plug to each endpoint. I am at a total loss otherwise. The engine runs well enough when not idling that I do not think it can be some sort of major cam timing issue or other mechanical fault.
Any and all thoughts and insight are appreciated.
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This is more of a long shot and while it can prove to give you hesitation, not a high idle as you have stated, but but maybe ECU is trying to figure things out, the coil packs? Have you checked those? I didn't see them listed here.
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OK, the issue is mostly resolved. The car runs, and I had a good time driving it for 30 miles, running it about as hard as hard as I could while keeping it under 5000RPM (I am going to put more like 100 miles on it before really revving it just to be sure the rings are worn in). It turns out that it was a software issue after all. I have a corrected high performance Sssquid tune in the car, which is what he has developed across something like 8 other 2.1L M42's from MM. After driving a turbo diesel for 7 months, I have to remind myself that punching the throttle at 2000RPM isn't going to do much haha.
With that said, the idle still has issues, but they are relatively minor compared to what I was dealing with. They seem to be heavily dependent on engine temperature. I have outright removed the LLCO wire from the Motronic connector, so I know it isn't that lol. Anyway here's where the idle seems to be at now, in the order that I encountered the issues:
1) The car did the thing where it stalled after running for a minute as I pushed the clutch in coming to a stop sign. It started right back up and did not do it again (for a while).
2) Once it was warmed up, it would stumble and catch itself as I came off the throttle approaching most stops, and it would intermittently exhibit a 800~900RPM hunting when sitting at idle.
3) I drove it to visit my parents, and it sat for maybe 30 minutes. When I got in to start it, it did not want to start. As it cranked it just barely gave an indication of a couple of attempts to fire, and a little throttle was needed to get it to actually start. The temp needle was a little shy of the 1/4 mark at this start.
4) As I slowed to turn in to my driveway ~20 minutes after #3, it stalled. I again needed to apply a little throttle to get it to start, and it stalled again when I let off the gas to park. I again needed to give it a little throttle to start it.
I still have the stock AFM in there, and it has the little extension harness / low-pass filter that BMW issued to most M42's at the time. I am replacing the CLT sensor when the new one comes in later this week, although the current one seems to Ohm-out just fine. Also, I assume that the super light RHD flywheel is not helping anything. I will still be re-checking for vacuum leaks and messing with bypassing the ICV as since the above issues are a lot more similar to ones people have with more "common" faults in these cars.
For the record, the 7.4lb flywheel is fun as shit. Effortless rev matching, no weird noises at start (some people said that the RHD flywheel sounded raspy, but I do not notice anything) and crazy good response. To hell with the noisy rattling from the transmission, BMW should have shipped these cars with light flywheels!
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OK, as promised it is time for the photo dump of app the stuff I have done since the last set of photos.
The rear shift carrier mount was in bad shape, and sort of expensive to replace, so I opted for the beefier Turner Motorsport upgrade. It was only marginally more expensive, and it would eliminate the last of the stuff in the linkage that was making extra slop. It does not fit exactly like the original one (the angle is a little different), but it is good enough to work properly. It was listed as being E30 compatible, so who knows.
(http://www.e30tuner.com/assist/m42hg2019/bmw079.jpg)
(http://www.e30tuner.com/assist/m42hg2019/bmw080.jpg)
I did make one small modification to the carrier. Rather than jam the mushroomed end through the new poly bushing (teehee), I just channeled my inner rabbi and filed it down. In normal operation the mushroom serves no function and just makes removal of the carrier more of a pain.
(http://www.e30tuner.com/assist/m42hg2019/bmw081.jpg)
(http://www.e30tuner.com/assist/m42hg2019/bmw082.jpg)
Here it is installed on the car.
(http://www.e30tuner.com/assist/m42hg2019/bmw083.jpg)
Here is the nice new 7.4lb RHD flywheel installed on the engine.
(http://www.e30tuner.com/assist/m42hg2019/bmw084.jpg)
I also bought the proper crank locking tool, which is a hell of a lot easier to use than the big ½” cold rolled plate I drilled holes in 15 years ago. It was $85 at Pelican Parts. The weight of the engine was more than enough to keep things from moving around as I torqued the FW bolts to 120 ft-lbs.
(http://www.e30tuner.com/assist/m42hg2019/bmw085.jpg)
Next up were the clutch disc and pressure plate. The FW and PP were dynamically balanced together and came ended up with <0.9 grams of total imbalance in the end. Cardelli Motorsports in San Mateo, CA did the balancing for me for $100 cash.
(http://www.e30tuner.com/assist/m42hg2019/bmw086.jpg)
(http://www.e30tuner.com/assist/m42hg2019/bmw087.jpg)
Next the transmission was bolted on. That was a super easy task with the engine up on the mobile workbench, and I got it to slide right into place. One hand to support it (so as to not load the pilot bearing excessively), one to start one of the big top bolts. And no, I did not bother cleaning the transmission. I had thought about it, but at that point I needed to get the project moving and out of the garage.
(http://www.e30tuner.com/assist/m42hg2019/bmw088.jpg)
And there it was, mostly ready to go back into the car. It had a nice new ground strap as well. I replaced all of the ground straps (engine, alternator, hood) with new ones from Bavarian Restoration.
(http://www.e30tuner.com/assist/m42hg2019/bmw089.jpg)
There were a few odds and ends to take care of before dropping the engine back in. Among them was purging the fuel lines that had sat for 7 months. This was pretty easy to do by looping the old feed hose onto the return hardline and hooking the battery up to the pump. If you hook the battery negative to the chassis and the positive terminal to C101 pin 13 (fuse box side) it will run the pump and have fuse 11 there for protection. I ran it for a few minutes and that was that. All flexible fuel lines up front were replaced with new ones.
(http://www.e30tuner.com/assist/m42hg2019/bmw090.jpg)
(http://www.e30tuner.com/assist/m42hg2019/bmw091.jpg)
Oh, and at some point I decided to cut my old flex disc in half to see how it is constructed. They are directional and need to be installed properly to put the proper parts into compression when applying engine power, leaving the other less stiff parts free for taking up vibration when engine braking. These things have some beefy fiber bundles inside (maybe aramid or glass, I did not check too closely).
(http://www.e30tuner.com/assist/m42hg2019/bmw092.jpg)
Anyway, here it is plopped into the car. The main items to reinstall first are the engine mount arms and mounts and the exhaust header. That saves you from a bunch of reaching around under there, and getting the header in/out with the engine in place is a hassle. A few of the other accessories were also installed. Leaving the intake manifolds off, and having the entire firewall wiring tray out, made it super easy to get in. I almost did not even bump the engine or transmission into the car at all while tilting and lowering it in. In the past the main trouble spot has been up at the firewall where the intake manifold would hang up on the wiring tray (or the main wire loom).
(http://www.e30tuner.com/assist/m42hg2019/bmw093.jpg)
(http://www.e30tuner.com/assist/m42hg2019/bmw094.jpg)
After bolting on some more stuff, I turned my attention to the engine wire harness that I had completely rebuilt. The final remaining task was to trim the ignition coil leads to their final length. I took measurements of the wires, where things were stripped, etc., on the original connectors and duplicated that with the trimmed ones. All of the sheathing is new since I changed up how the bundles route from the main loom on the firewall, and getting it all neatly in place was a bit of a chore. The main 0.56” ID sheath that the 12 wires for the 4 coils ran through split into four 0.25” sheaths, and to get clearance on the ends for the heat shrink tubing and stuff I needed to slide it all up into the main one. Windex for the win, it does wonders for enabling things to slide around while also drying quickly. Anyway, I am getting way too excited about wiring lol.
I started by figuring out how exactly I wanted to route the main bundle to give it a proper service loop for strain relief, and then I played with a few different configurations for the individual leads. The one I settled on worked out so that none of the smaller looms would rub on the metal plug retainers, none of the plug ends would be subject to any movement from the chassis loom and everything could be conveniently zip tied into place and serviced in the future. This is a COP plate kit from HQ Autosport, but I made some changes to the fasteners and added some washers as spacers for ergonomic reasons (maybe I will do a write-up of how I improved upon it sometime).
(http://www.e30tuner.com/assist/m42hg2019/bmw098.jpg)
(http://www.e30tuner.com/assist/m42hg2019/bmw097.jpg)
(http://www.e30tuner.com/assist/m42hg2019/bmw096.jpg)
(http://www.e30tuner.com/assist/m42hg2019/bmw095.jpg)
OK, I will try not to type another giant paragraph about wiring. As much of a pain as it is, it is sort of fun if you are doing it right.
Once things were roughed into place, I cut the leads and sheath pieces I would need. From there it was just a matter of crimping the terminals on and putting the connectors together. As another FYI point, the rubber boots for these connectors are a real pain in the ass to get onto the 0.25” sheathing. It is the same diameter as the original sheaths, but the boots are either not intended for use on that size, or they are supposed to be REALLY snug. Getting them onto the sheath was a bitch…be warned!
(http://www.e30tuner.com/assist/m42hg2019/bmw099.jpg)
(http://www.e30tuner.com/assist/m42hg2019/bmw100.jpg)
(http://www.e30tuner.com/assist/m42hg2019/bmw101.jpg)
Here it all is laying in place before I actually finished it up.
(http://www.e30tuner.com/assist/m42hg2019/bmw102.jpg)
And here is the final setup. I am pretty pleased with the little service loop that connects the chassis to the engine. Compared to how I trimmed and routed stuff on the old harness back in 2006 when I invented the COP conversion (fun fact!), this is immensely better. Considering that shitty wiring job lasted 14 years with no broken wires or pierced insulation, this should outlive me.
(http://www.e30tuner.com/assist/m42hg2019/bmw113.jpg)
(http://www.e30tuner.com/assist/m42hg2019/bmw112.jpg)
And so, here it all is today. I have ~160 miles on the engine and have been driving the dog shit out of it. Damn it is fun, and despite being able to feel the car’s age, it is a hell of a lot more fun than most newer cars. All drivetrain and suspension stuff is effectively new, but it’s still based on 40 year old automotive design, so the way it handles and reacts feels a little dated. BUT, it is a go-kart compared to heavy newer sports cars, and despite being slower it has a feel that you don’t get anymore. I had mostly forgotten how much I enjoy driving this thing over the last 7 months of waiting and toiling!
(http://www.e30tuner.com/assist/m42hg2019/bmw109.jpg)
(http://www.e30tuner.com/assist/m42hg2019/bmw110.jpg)
(http://www.e30tuner.com/assist/m42hg2019/bmw111.jpg)
Other random crap….
As you all have seen, I was chasing down gremlins as I tried to get it to run. Since roguetoaster sold me an ICV that was in cleaner shape than my old one, I decided to dissect the one I took out. I’ve never seen one opened up, probably because you have to totally destroy it to get it apart. The outer housing is staked in like 10 places (both the end, and on the sides) and one part is pressed in. Ultimately it is just a simple little electric motor. The design is sort of unique, and clearly not intended for high torque, but it works well enough. The single coil that makes up the stator interacts with the magnetized center cylinder and funky-shaped upper section that serves as a rotor of sorts. The I assume that the shape of the ferrous top is what allows it to interact with the symmetric magnetic field from the coil (I wouldn’t expect it to generate motion at first glance, were it not for the wedge shapes at the top which you can sort of see in the next pic).
(http://www.e30tuner.com/assist/m42hg2019/bmw105.jpg)
(http://www.e30tuner.com/assist/m42hg2019/bmw106.jpg)
This set screw (which is epoxied into place) sets the end stop for when the thing is not energized. It leaves the ICV open an amount that corresponds to the engine’s air needs at the designed idle speed, hence why unplugging it usually leaves the car idling reasonably well.
(http://www.e30tuner.com/assist/m42hg2019/bmw108.jpg)
This little flag is the thing you see moving through the hose barb. The ECU sends a 100Hz PWM signal to the ICV, and this little door flaps open and closed at that rate. Varying the on/off time in that 100Hz signal is how the “average” opening amount is created by the ECU to control idle (Motronic also uses enrichment and ignition timing to control idle speed and stability).
(http://www.e30tuner.com/assist/m42hg2019/bmw107.jpg)
Back when my fuel injectors were stuck shut, I tried to free them with a programmable power supply (you can program voltages and on/off times to make a pulsed output). I also had some spare wire harnesses that were cannibalized to rebuild the one in the car, so I took more parts from them and made my own little debug connectors for the injectors (and some other stuff just in case).
(http://www.e30tuner.com/assist/m42hg2019/bmw103.jpg)
(http://www.e30tuner.com/assist/m42hg2019/bmw104.jpg)
Phew…there it all is. Things are mostly wrapped up now, and I will make new threads for the other non-rebuild stuff I came across in this project. I’m going to cross section one of my old ignition coils for fun, and probably take apart the old MAF sensor element. Mostly I need to remember to make a DIY for how to improve the HQ Autosport COP bracket kit, and try to get measurements of the wiring dimensions. Granted, many of the measurements are useless unless you totally rebuild your harness since the stock ignition coil wire routing won’t leave you enough length to do it my way.
Thanks a lot to everyone for all of the input, encouragement and discussion over the many months since this all started! The E30 community is probably the #1 reason why I still have this stupid car lol.
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great pictures. I highly recommend the e30 m3 engine harness cover that goes on the passenger side. Will clean up the by even further. When I got it, it was expensive, like $20, no idea what the m3 tax is now a days.
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That certainly is a comprehensive read. It's almost exhausting to read it, I can only imagine what typing it all up was like. Thanks for sharing!
I'll have to check out that flywheel over at R3v...I couldn't agree more about the fun factor. A lightweight single-mass flywheel is always near the top of my upgrade list. You're running an awfully light 'wheel, but given the lightweight M42 & G240 components it must be a real pleasure to shift.
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Awesome updates, happy to hear its back in working order!
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great pictures. I highly recommend the e30 m3 engine harness cover that goes on the passenger side. Will clean up the by even further. When I got it, it was expensive, like $20, no idea what the m3 tax is now a days.
That certainly is a comprehensive read. It's almost exhausting to read it, I can only imagine what typing it all up was like. Thanks for sharing!
I'll have to check out that flywheel over at R3v...I couldn't agree more about the fun factor. A lightweight single-mass flywheel is always near the top of my upgrade list. You're running an awfully light 'wheel, but given the lightweight M42 & G240 components it must be a real pleasure to shift.
Awesome updates, happy to hear its back in working order!
Thanks. Yes it is a tremendous relief to have this thing running well again. It is in bad need of a full repaint job, but I guess it's a real "sleeper" at the moment. I can't believe that I have had this car for almost 15 years, and have been driving this model of car for 20 years! I will say that having a second car that is newer and more reliable helps a lot with being able to enjoy the project car.
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It has been a couple thousand miles now, and I wanted to pop back in here with an update. Well, less an update than just a note. I am absolutely loving this engine and the car is more fun than ever. Whatever was wrong with the engine as it was originally built may never be known, but it is in a lot of ways a totally different beast now. It revs smoother, makes more power, makes less "hissing" noise, gets 20-30% better fuel economy, does not leak or consume oil and just generally feels more composed. Granted, I now have a really good tune for it from Sssquid, and a considerably lighter (and dynamically balanced) flywheel, but even still the engine itself is better than it was. All said, this is the sort of engine I feel like MM is probably known for building, and while it was frustrating as hell to never really feel satisfied with the original one, I am satisfied now. MM stood behind their product and reputation all along, and I would do business with them again.
I will probably never know what was wrong with the original engine that they built for me in 2012, and my only guesses are:
1) I did a lousy job of reinstalling the head after they replaced all of the valve springs (the springs they originally used were defective) and there was a pinhole leak or leaks the whole time. It seems exceedingly unlikely that a compromised HG survived 7 years of my hard driving.
2) A valve was slightly bent and not replaced when I sent the head back after the 2nd spring failed. Again, it seems sort of unlikely since they had the head totally apart to swap in the known-reliable dual spring setup (the original build used single springs).
3) MM did not correctly mark which valves came from which port, reinstalled some into the wrong locations & didn't re-lap them to the seats. This is my leading guess and I think that it would explain why so many of the issues I had seemed like they could be explained by compression loss / combustion chamber leakage.
Jim said that they did not find anything conclusive in the engine when I sent it back late last year after the HG completely failed. The cylinder bores were 0.001" out of round, which was not great, but is also not enough to completely explain the poor running. The current engine is built with a fresh block, with the bores matched to the old pistons (with new rings)...I sent the old engine back right around Thanksgiving last year, and they determined that it would be quicker to match-bore a fresh block than to try to get new pistons since supply logistics were a mess at the time. Completely machining the fresh block likely cost them more than a new set of pistons, but I appreciated the effort to turn things around fast. Anyway, if the old engine's problem was in fact #3 (poor valve sealing), they might have yanked the head apart before checking the sealing, or if it was messed up maybe they didn't want to say anything since that's sort of a head-slapper mistake. Either way, they put on their latest multi angle grind & new seats to match, so it is not an issue now (if it ever was).
Last time I spoke with MM to let them know I was pleased with the engine, they mentioned that they were developing a complete ITB kit for the M42. I think that I will give them a ring in the next week or two to see how that is coming along. Dyno data I have seen from M42's with dBilas and RHD ITB kits seem to show gains across the entire RPM range, and I would certainly be happy to get a bit more area under the curve. RHD's kit is well designed, priced well and available now, so it is one consideration. I'll see how things turn out with MM's kit. I am still very eager to get out to Missouri in the spring (fingers crossed that the COVID nonsense dies down by then) to visit Sssquid and MM. If travel is an option by then, I sort of want to get the car trucked out there for some live dyno tuning, and if the ITB kit is ready by then I can install it at MM, get the throttles synchronized and have some fun with them. Anyway, if I could hit 100HP/L I would be pretty stoked, even if that is a totally arbitrary goal.
The other item I am still thinking over is which stand-alone ECU system to go with. The "easiest" options are the PnP MS3Pro for M5x engines, and the Link E36X ECU, since both use the 88 pin connector and I would just need to move some terminals around. The other system I like is AEM Infinity 358 (can drive "dumb" coils directly) and the 508 (can't drive dumb coils, but has built-in WBO2 control and logging), with the major downside being the top-entry harness connection which would be tough to fit into the glove box and still clear the plastic cover. Motec and other motorsport ECUs all seem like they are likely to be entirely overkill for my application. I'm open to suggestions though.
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Great update and keep enjoying the drives.