M42club.com - Home of the BMW E30/E36 318i/iS
FAQ / REFERENCE => How-To's => Topic started by: sheepdog on July 11, 2006, 08:42:23 PM
-
Not really a how-to or guide just what has happenned, and what I think may have led to it.
First off, based on what Bmwman91 and my discussion, I think it is safe to say the M42 pickup screen is worthless. If something gets into your pan, it will end up in your pump. Second thing to remember is that the pump housing on an M42 is aluminum, THIN aluminum. The shitty part is that it is located against the block. Dealer replacement parts will run nearly $1000 by the time you are done.
What you see below is what happens when the timing chain decides it is time to start falling apart, yet not fail entirely. The rollers go bad, end up in the pan, and then get sucked up, the result is what you see below.
Something that was found along with this though, is that all of the sprockets were extremely sharp and worn.
While Bmwman91 and I are not sure (he has doubts), there is a possibility that replacing the timing chain tensioner contributes to this problem. Reason being, both of us had this happen, and had replaced the tensioner a few thousand miles before (probably between 3-5k). Which is probably enough time under added tension that the chain finally shredded apart enough to cause problems. Though we are not sure. Any input form others woudl be helpfull. The bad part is that it could have happenned regardless due to age or stress, plus not changing the tensioner is just as bad possibly..
My best recomendation is change your chain at 120k, I have heard that BMW recomends it at this mileage. If you must do the tensioner, I would recomend pulling teh cam gear cover (very easily done) and popping teh tensioner open before starting the car, rather than use the "rev to 3000 for 30 secnd method". During that 30 seconds, your chain is slapping around an awefull lot.
Also, change your chain. While a pain in the ass, it is FAR, FAR easier than what I now have to do.
What is involved in the T-chain (basic overview, yes, it is a lot):
Drain oil, drain coolant, pull the hood off, remove rad hoses and heater return hose, remove radiator, remove shroud. Remove fan, clutch, all belts. Remove the A/C pump and mounting bracket. Pull the lower and upper pansd, then pull the thermostat and housing, (you may get away without pulling the water pump, but you will have to pull the pulley) valve cover, upper t-chain/cam cover, timing sensor, lower crank pulleys, and lower t-chain cover. The pull the tensioner, upper chain guide, and idler gear. You should be able to pull the chain but you may want to remove some guides to make things easier. I recomend replacing the cam gears, (take a picture for proper bolt placement), idler gear, and crank gear along with the chain otherwise you may end up doing it again sometimes in the future.
Now if you are unlucky and wait too long...
You get to get a ride home and then pull the oil pump/front engine assembly, which you see below. This means pulling the water pump (for sure) as well as dealing with the profile gasket, and possibly the head if you do not figure out how to do it without. Bmwman91 did it without, and I am planning to.
This chunk of aluminum is VERY expensive, and is a shitty design. If you have to do this, buy another motor and cannibalize parts.
What it should look like.
(http://www.m42club.com/images/doug/IMG_3886.jpg)
What mine looks like. Notice the crack, about 3-4inches long! and notice the lower chain guide, the plastic is completely gone from the mounting post. Looks like there may be a crack on the other side of teh housing as well.
(http://www.m42club.com/images/doug/IMG_3883.jpg)
-
Well, I have replaced tensioners on both cars and I never put it in unspring...for fear of this exactly. The guides I have read for tensioner replacement call for you to remove the timing case covers and press on the tensioner with the guide rail to release it manually prior to starting the motor...probably for the exact reason Sheepdog has mentioned here.
My chain was missing TONS of pieces because the previous owner had let the tensioner go for a loong time (I am guessing), but did not replace it because it is normal for a lot of older BMW's to be sorta noisy.
-
In the garage, we thought the crack only went across the top area. The pics revealed it was much worse and wraps around underneath. After looking some more though, it looks like it may have another on the opposite side.
-
Yeah, I am leaning toward letting the tensioner go bad for so long is a main cause to the chain going bad, though worn sprockets do not help and mine were bad. I do wonder if putting in the new one did not make things worse after it was going bad already.
At any rate, my engine was noisey and unfortunately I had no idea what actually was "loud". There are no other 318's around to listen to. At a show though a BMW master tech noticed and told me even though I was planning in doing the tensioner soon anyhow. It was more quiet, but still a rather noisey motor.
If in doubt, change your tensioner.
-
A bad tensioner lets the chain flop around causing excessive wear on the rollers and gear teeth. The worn through rail in the photo is worn on the slack side assuming a BMW engine rotates clockwise from the front. The tensioner takes play out of the slack side and drag keeps it tight on the other. The cam gear teeth and chain rollers are easy enough to check if the engine is noisy - remove upper front cover. A worn tensioner causes a dinstinctive sound. Once you know what it is, it's obvious. Until you know it's baffling. Someone pointed it out to me. Listen to a new 318is. They're pretty quiet.
-
For those wondering about costs to do this...
For me:
$200 used motor
$80 in gas (St. Louis to Chicago and back, yes, I am nuts I guess)
$20 oil
$80 in misc gaskets and such (I am also doing hoses and belts, but keeping the waterpump as it is in good shape and expensive to replace).
I am also changing to the e36 timing chain, rails and sprockets.
About $380
Normal cost for this (based on real OEM) this is bare minimum:
$300 Timing chain case
$53 oil pump
$120 chain
$55 Guide rail (for some reason the same one broke on me and Bmwman91's)
$100 gaskets and such, buy a bottom end kit
$20 oil
$25 oil pump pickup
You may also need to replace sprockets, mine were very sharp which is not good. $220 A full guide rail set is about $220.
Basically if you need it all, About $1000.
Do yourself a favor, find a slightly used e36 engine to cannibalize.
-
My cost:
$80 Used Timing Case & pump gears, Shipped (from some guy on Bimmerforums)
$60 for all gaskets (Pelican Parts)
$30 New Pump Sump Screen Boom
+
-------------
$170ish
Now, I had just rebuilt the whole timing case about 2 months prior. All those parts through Pelican Parts cost me about $450.
-
My cost:
$80 Used Timing Case & pump gears, Shipped (from some guy on Bimmerforums)
$60 for all gaskets (Pelican Parts)
$30 New Pump Sump Screen Boom
+
-------------
$170ish
Now, I had just rebuilt the whole timing case about 2 months prior. All those parts through Pelican Parts cost me about $450.
I think we both got off cheap.
I cannot even imagine paying a dealer to do it all with new parts, YIKES!
-
I may have a similar issue. What I know so far about my "new" cabrio is that about 40k miles ago it had the hydraulic lifters and chain tensioner replaced.
The latest service record (2/06 - last time car was driven) from the previous owner shows that they found a lot of metal and plastic in the oil pan that was clogging the pump pick up. They removed the debris, re-installed the pan and filled it with oil. They wrote "engine noisy. parts in oil pan may be from timing chain tensioner guide rail coming apart."
What do you guys think? Does it sound like I have the same thing going on?
Thanks
Rachel
-
How many miles on the engine?
-
How many miles on the engine?
115k
-
It sounds like guide rails at least may be the problem. The guide rails are the only plastic I know of in the motor that are likely to disintegrate. The metal would be the chain and gears. You'll have toi pull the covers off to tell for sure. You might park beside another M42 and see just how loud it is. You may not need to do anything. I think M42's are just plain noisy!
If you do the work yourself, a good used motor would probably cost what the parts would if it looks like the pic above or even needs guides, chain, and a few gears.
Where do they get those parts prices? The main cover is $300 by itself.
-
I may have a similar issue. What I know so far about my "new" cabrio is that about 40k miles ago it had the hydraulic lifters and chain tensioner replaced.
The latest service record (2/06 - last time car was driven) from the previous owner shows that they found a lot of metal and plastic in the oil pan that was clogging the pump pick up. They removed the debris, re-installed the pan and filled it with oil. They wrote "engine noisy. parts in oil pan may be from timing chain tensioner guide rail coming apart."
What do you guys think? Does it sound like I have the same thing going on?
Thanks
Rachel
Not good.
I would stop driving. Pull the lower pan, and pull the upper timing case cover (cam sprocket cover) and valve cover. Takes all of 5 minutes, you will need some new gaskets. Take a look at your chain, look for missing rollers, all you will see is the pin. Mine was showing only the pin in some cases, and parts of rollers were missing.
Be prepared to order up a new chain (bend over), gasket kit, lower and right side guides immediately.
That is exactly what you will find in there when it goes.
Be prepared, you may find a cracked pump, though not punched though, you may also find very worn sprockets. Better to get it now before the timing case/pump housing gets damaged.
Take a look at my pan when I pulled it...
The black chunk is plastic is from the guide. The bolts were from the upper pan, and bits of metal are rollers from the chain. Also lots of aluminum. Whoever pulled that pan and did nothing should be shot as ANY time you find metal in the pan it is a bad thing unless it is fine metal shavings from a recent rebuild.
Check this picture.
http://www.m42club.com/forums/vbgarage.php?do=getimage&id=4 (http://www.m42club.com/forums/vbgarage.php?do=getimage&id=4)
-
What did it sound like. Did you pull the pan for checking out what happened to Febi with the gasket/loose bolts problem or was it because it was noisy?
-
What did it sound like. Did you pull the pan for checking out what happened to Febi with the gasket/loose bolts problem or was it because it was noisy?
Well before I changed the tensioner, I had a lot of ratle from about 3000-4500rpm. Afterwards, the rattle was muffled and from 3750-4250 or so.
The problem is, I have never heard a stock m42 in proper condition run, so trying to tell you how different it sounded is difficult.
I was planning to pull the pan that weekend to check for what happenned to Febi. When it happenned, I assumed I had suffered the same fate. I wish. This is far more expensive, and a whole lot more work. Had it been what happenned to him, I would have been running again in a couple hours rather than weeks.
I have to admit, the more I work on this engine, the less impressed I am with it. It runs good, but the engineering behind it is crazy. Some of it is genius, other portions of it seem to be designed by a moron. German engineering my ass.
-
I have to admit, the more I work on this engine, the less impressed I am with it. It runs good, but the engineering behind it is crazy. Some of it is genius, other portions of it seem to be designed by a moron. German engineering my ass.
I think the greatest feat of German "engineering" on the M42 is the oil sump in front of the crossmember. Everything is a compromise in design. The M42 is a rather high output for it's day and it does have a chain instead of a belt. To put the sump behind the crossmember would require a redo of the crossmember or raising the motor which is not desirable from a handling standpoint. It would require a separate suspension and crossmember layout for the four cylinder motor - translation $. That may be why the stock ride height is so high - translation $.
-
I think the greatest feat of German "engineering" on the M42 is the oil sump in front of the crossmember. Everything is a compromise in design. The M42 is a rather high output for it's day and it does have a chain instead of a belt. To put the sump behind the crossmember would require a redo of the crossmember or raising the motor which is not desirable from a handling standpoint. It would require a separate suspension and crossmember layout for the four cylinder motor - translation $. That may be why the stock ride height is so high - translation $.
Ford has had it there for years.
My complaint is the aluminum oil pump housing, which is very thin, not tomention aluminum, the pickup screen to stop anything from getting into the pump, that does not stop debris from entering as it goes right through, the excessive number of gaskets used to seal up the front of the engine, the cooling pipe down the side, the rediculous vacuum line shapes (why is the 3 way splitter rubber instead of a plastic "t"?). The fact that they make it so easy to change a thermostat or waterpump, yet attach the fan in a way that it itself is royal pain in the ass.
Things like that.
And it is not just the engine. The entire car is like this. Take the steering rack for example, it is SUPER easy, yet the CSB is somewhat of a hassle.
Anything you mess with on a semi-regular basis is simple to do, anything beyond that, is a royal pain in the ass.
-
Well, I do take back what I said about the screen, it does seem sufficient in strength, I could not flex it with my hand. That does not change the fact that a peice of timing chain went through it! Makes you wonder what kind of suction is actually going on down there to be capable of that.
Sorry so blurry, it was hard to get decent pics.
(http://www.m42club.com/images/pumpsuck/IMG_3912.jpg)
(http://www.m42club.com/images/pumpsuck/IMG_3901.jpg)
-
Well....
Here is what is left of the inner oil pump ring....
Boom!
All the kings horses and all the king's men... yeah, yeah, yeah, them fuckers could not put this peice of shit back together again either!
(http://www.m42club.com/images/pumpsuck/IMG_3930.jpg)
Here is the outer ring, still in the housing...
It is seized in there, it took a bit to get it out, as you will see later.
The arrows pount to destroyed teeth from metal getting in between.
(http://www.m42club.com/images/pumpsuck/IMG_3926.jpg)
Here is an interesting shot:
Arrows 1 and 2 point to cracks in the housing. They are stress cracks from how tight the outer ring was pressing against it. It was so tight when hot, that on each side of each crack, the part is warped. There is still more to see of how bad this truly was in the next picture.
Arrow 4 shows how far around the cracks went. 3 points to the uppermost area undamaged. Odd, since just below that is a rib, hower it cracked the rib and left this. It did still score it though. Look at teh gouges all the way around.
(http://www.m42club.com/images/pumpsuck/IMG_3941.jpg)
Here we have the misc. parts of the oil pump. The big ring is the oil pump backing plate. Notice the chunk missing!. That lines up with the 2 cracks in the previous picture. You can see the ripped out part just to the right of it, it looks like a washer. Look at the scoring on the back plate.
(http://www.m42club.com/images/pumpsuck/IMG_3944.jpg)
-
Anyone have an odd oil or coolant leak they just cannot find the source.
This is the backside of the timing chain case that goes against the block. You can see it had been leaking. Which was probably caused by the fact that some bolts were barely hand tight!
Anyhow, the top area, opens to air, no seal between it and the head, and there is about a 1/16-1/8in gap there. I had all sorts of sand and crap fall out of there.
Thing is, looking at this, you can see I had seepage from the coolant and oil system on the upper right hand side area.
If you have mystery leacks, this could be your cause. Some things to keep in mind, when I worked on aircraft, we hessitated to just tighten leaky lines and such, because while you may stop it, you may also make things worse. This gasket is a royal BITCH to get to. It takes A LOT of work.
For those unsure of what you are looking at, this is the back side of the timing chain housing. This is the block side. It is also one expensive chunk of aluminum. This one is now worth about 25 cents to a local recycler.
(http://www.m42club.com/images/pumpsuck/IMG_3947.jpg)
-
This is one of BMWman91's pics from when his went. This mounts on the front of the block in this picture.
That is also shows how much you have to do to get this off.
(http://www.m42club.com/forums/vbgarage.php?do=getimage&id=31)
-
im sorry for you pains mate. if it helps id like to say this is a very informative thread, keep us posted with the great pics and details
-
It looks as if the culprit is either the timing chain and plastic guides or the lower sump gasket and pan bolts.
1) Any ideas on what would be the recommended "M42club.com" service interval for replacing the lower pan gasket and the timing chain and guides?
2) Does BMW have a recommended srvice interval for any of this?
3) Also would it be worth it to go ahead and take the timing case off the block and replace that gasket?
I'm starting to worry as I am at 196,000+ miles and have only done a chain tensioner at about 140,000. Parts are pretty much $300 for the chain, tensioner, guides, and gaskets. Or maybe I should just wait and use the "what's that noise" method.
-
The destruction was certainly caused by the timing chain roller(s) getting through the pickup screen, plastic could not do this. What caused the chain to destruct is partially open for debate. The chain was certainly in bad shape due to being run too loose. The second half is that changing the tensioner while in the condition it was in, may have acclerated its destruction. For those wondering, there was nothing ever came out in the oil (I watched and listened for anything) and nothing was in the filter when the oil (and filter) was done just before (2000-3000 miles previously). The tensioner had been in for maybe 3000-4000 miles. It may have also just decided it was time.
Honestly, I am just amazed any of these motors are holding together. I am not sure I want to even check my rod or main bolts for fear they will be loose. On the other hand, I do not want to risk disturbing them or distorting the bearings. I have been told that unofficially, the t-chain is due at 120k miles. Is it true? I have no idea, but it tends to go with most other timing chain replacment times. Though I have also heard of many chains going 500k plus despite this recomendation from manufacturers. I have also heard the tensioner should be changed every 40k miles. If this engine blows after all this I am buying another motor and dropping it in. I am NOT doing this again. There is a good side to this, I think (hope).
Here is what I will do, or do over again (preferably while it is out, or never):
Which by the way, I would probably just pull it next time, seems like it would be simpler.
First pull the pan, and check the bolts and sump, all bolts removed one at a time and locktighted and retorqued 15% over stock torque numbers.
Then the front of the engine, pull the covers off. Check the sprocket teeth and chain, if bad, pull the housing and replace the gasket while there, you already have 90% of the work done, may as well. Better now than later. If the chain and sprockets are fine, replace the tensioner, and Re-torque the entire t-chain housing, and work my way back out from there re-torque'ing and locktight'ing everything.
Consider replacing all vaccuum lines, coolant hoses, belts, waterpump, and t-stat as well as plugs and wires. A lot, yes, but so much is easily accessed at this point that requires so much removal to do again later, it is rediculous not to. You may not think so now, but trust me, by the time you get the t-chain husing off, and the engine is very easily accessed and you realize what it took to get there.
-
im sorry for you pains mate. if it helps id like to say this is a very informative thread, keep us posted with the great pics and details
Thanks, glad someone is getting something from all of this.
This will be a great car by the time I get done with this, however I am almost ready to move on. Not a perfect car yet, but it will have had a lot gone over by the time it is done and should be mechanically sound for a while. I love this car, but I have too much time underneath it, which will not improve much considering how much I drive it.
Last 2 years or 20k miles, which is when I got it, I havereplaced or upgraded:
6 tires (Yokohamas)
steering rack
tie rod ends
guibo w/new bolts
center support bearing
fuel tank (that was as much fun as this)
all belts
main hoses (May do the rest)
lots of vaccuum lines (may do the rest)
air conditing
stereo (Alpine)
speakers
brakes (Axxis Ultimates)
Headlights (Hella upgrade) h1 100w. high / h4 Silverstar lows (bright as hell)
Shift knob
2 rims
rearview mirror and mount
Drivers window
Lots of knobs and switches
Fog lamps (cheap Piaas, not great looing, but necessary)
fixed winsheild washer splitter
fixed wipers (one blade would not stay tight)
replaced bottlecap spare with bbs (no idea why it was like this)
Got the parts and plans to fix central lock system, re-paint the lower black body area, and straighten the bumper alignment. Probably put a chip soon too.
-
Like everyone else has said, at least the silver lining is that 1) you know it's been done right now, and 2) This has been a very informative and helpfull thread for the rest of us. I, for one plan on putting this information to good use, as time and $$ allow.
Unfortunately, it'll have to wait till after I move to Pensacola here in about a month. I'm sitting right near 150k right now, so everyone cross their fingers that it'll make it!
Keep the updates coming. I may not be posting much with everything on my plate (new baby, graduating, commissioning, transfering to P-cola), but I'm reading every day.
Brian
-
Just a heads up to those who end up replacing the timing chain housig,
you do NOT have to lift the entire engine or remove the engine.
Unbolt the passenger motor mount from underneath, place a 6in x2in block of wood against it (vertically), then use a floor jack to gently lift the motor up a bit. This will give you the clearance necessary to clean out the gasket and remove the bolt above the steering rack.
Make sure to check that things are secure before shoving your fingers up in there. Also use a mirror to check that all of the old material is removed.
You should be able to slide in the new gasket from the front.
Oh, a bit of advice, if you buy a lower end gasket kit, be sure to also purchase a profile gasket, as they are not included. Ask how I know... :mad:
Try finding one at 4pm on Sunday of a 3 day weekend...
-
I experienced this on my sedan a while ago. Started her up on my way to work one fine morning...Oil light comes on...shiet :mad: noticed car was low on power and rattles like a tractor. Oil pressure is very low. The car can still be cranked but its VERY LOW on power.
I have a lower mi. used motor to swap it out with. I might just salvage some parts from the old motor to keep as spares since I have no desire at the present time to rebuild it considering time and resources available.
This issue seems to be random depending on the history of the car along with partial servicing (e.g. when doing the timing chain tensioner alone too late) versus complete complete timing chain case items being replaced (e.g. when doing the profile gasket)
Dunno how I missed this post earlier on!
-
Excellent thread. I feel lucky that mine made enough noise in the driveway when the previous owner brought it to my house for me to replace EVERYTHING prior to even driving the car. My lower guide was broken in a couple places and my chain was about to fail. I also found that while I had no bolts in the sump none of my internal oil pan bolts required a wrench to remove.
-
Hey guys, the m42 I got in my car is a 1994. I know BMW made some modifications to it compared to the 1991 one, so does anyone know if it still has all the problems mentioned here and in the oil pan thread??
-
Hey guys, the m42 I got in my car is a 1994. I know BMW made some modifications to it compared to the 1991 one, so does anyone know if it still has all the problems mentioned here and in the oil pan thread??
Absolutely, but it does not have a 2 piece pan, and all bolts are outside.
Easier to check if they are loose or have fallen out. However if the pickup bolts fall out, you will not be able to look as easily. This is less of a problem than the pan bolts though.
This is also a problem on 5 and 7 series motors as well.