M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Engine + Driveline => Topic started by: tim_s on December 19, 2006, 05:03:37 PM
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Hi guys,
I'm going to rebuild the spring assembly for the oil pump shortly, and was wondering if anyone had attempted to slightly raise oil pressure by packing washers in the spring assembly? I'm not too happy with the oil pressure at the inlet side of the cylinder head; but this has been an issue since before I owned the car (I bought the car prob 5 years ago at 70k miles); while replacing parts in there I'm wondering if i could just tweak it up to help with higher rpm running. Just an idea at the mo, but was wondering whether anyone has any thoughts?
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seems like it should work, i would talk to a machine shop or something before you go through with it though
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Adding shims will only compress the spring, it won't add to it's calibrated strenght which is what holds the valve. If you want more oil pressure, I'd suggest getting a stronger spring or better pump. But too much pressure is not better then not enough. If I were you, I'd go another route to ensure that the head is lubricated appropriatly. See how they do it in high reving race cars that are subject to big Gs.
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Adding shims will only compress the spring, it won't add to it's calibrated strenght which is what holds the valve. If you want more oil pressure, I'd suggest getting a stronger spring or better pump. But too much pressure is not better then not enough. If I were you, I'd go another route to ensure that the head is lubricated appropriatly. See how they do it in high reving race cars that are subject to big Gs.
washers will help.
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Adding shims will only compress the spring, it won't add to it's calibrated strenght which is what holds the valve. If you want more oil pressure, I'd suggest getting a stronger spring or better pump. But too much pressure is not better then not enough. If I were you, I'd go another route to ensure that the head is lubricated appropriatly. See how they do it in high reving race cars that are subject to big Gs.
Any more info regarding other routes etc?
I understand what you're saying regarding spring rate remaining unaffected by adding shims (assuming that the spring rate is not progressive), but regardless increasing the compression on the spring, the force on the valve will be greater, right (and thus more force required to move the valve and relieve oil pressure)? I'm not looking to significantly raise oil pressure, but am not too happy with the current state of affairs with regards to the inlet side of the head; its caused light scoring of the cam bearings etc over time, which I've polished out, but don't want a repeat. I also think this may resolve some tapping from the inlet tappets.
On another tack, anyone know what the difference between m42 and m44 oil pump rotors is? They have different p/nos, and the m44s I've worked on seem to have impressive oil pressure.
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Too much pressure is not a good thing. Racers use high volume pumps which gives them slightly higher pressure due to the extra fluid, but just raising pressure can damage the bearings. Febi's pro-built engine uses a stock pump, I think we should be fine.
If your head is not getting enough, either look into a new pump and timing housing (you need both) and get some brushes to run down the oil channels and clean out the sludge (brushes made for this purpose are available, try Summit or PAW). Even if you managed to raise pressure and vollume, there is nothing to say it will do anything dramatic on the top end if there is a restriction in the feed channels.
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Yeah I thought about it a little more and adding shims will slightly raise the pressure but like Sheepdog said, more pressure might not be the answer. When is there an oil shortage in the head? During normal driving or during hard driving and high revs? How old is your pump?
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Thanks for the replies!
The engine is clean throughout, and the oil pump rotors are in good condition. I only built the 2.1 about 10k miles ago. All oil channels are clean, there is no sludge anywhere; I've owned the car since 70k miles, done 5k oil changes with synthetic oil, plus I cleaned every single component when I rebuilt the engine. It's safe to say the engine is very clean and no passageways are blocked. I'm going to change the spring, valve and pickup soon, as I didn't do these when I rebuilt; i'm regretting that now! Will prob do the oil pump rotors too for good measure.
The oil pressure at the oil switch was ok when I last tested it. This is not a major issue, but the oil system doesn't seem to be as good as perhaps it might:
Cyl head pressure seems low as there's more or less no oil being blown out the rocker cover breather and there's inlet lifter noise. Coupled to the fact that the inlet cam had some scoring, and whirred since I owned this car (until I polished the bearings etc), I've come to the conclusion that even before I owned the car (the inl cam whirred when I bought it, over 50k miles ago), there's prob been an issue with oiling on the inlet side of the cyl head.
As for increasing oil pressure not necessarily being a good thing, I understand that too much oil pressure can be problematic, but I'm only considering a very slight change, not to an extent where this would become problematic for bearings etc. I've seen similar methods used for a very long time in motorsport; in fact it was thinking about old rally minis that got the idea into my head in the first place!
I think I'll probably just rebuild the oil pump and check over the lower timing case to make sure all is well. I will do some comparisons between my oil pump once rebuilt and an m44; should be interesting.
I'm hoping that its just a partially blocked pickup, or some air getting through, but the engine is worth too much to take any chances with.
Any other ideas gratefully received!
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Oh and the lifter noise is intermittent; sometimes it does it more or less all the time (not at idle, but coming off throttle and often on throttle too!), other times I can do a journey and have very little sign of noise. And it is not timing chain (new) or injector tick!
It can be infuriating though, as an engine I've spanked all this money on should sound good, not like a tractor!
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Try something less viscous, like veggie oil.
lol
But seriously, I am interested in the results of this. My lifters are noisy as well and I have wondered about sufficient oiling.
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Oh yeah bmwman, you reminded me of something I hadn't mentioned to you guys. I changed my lifters over a few months back for some spare e36 lifters I had lying around to try to reduce lifter noise. My old lifters ended up in a much newer e36, in which they were jus about silent. In my car it is mainly the inlet lifters that make some noise.
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what if its the lifter tray that is worn, have you checked the bore sizes of each and compared? perhaps its moving around a little...
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nope, good call but its not that! Noise is intermittent for a start, plus i think the problem has spanned two sets of carriers. I drove the car for the first time in a while today and the noise really isn't too bad and is intermittent enough that i think new lifters would cure it; i'm still going to do some work on the oiling though as regardless I'm not convinced its getting adequate oiling there. The breather not getting much oil blown through, for instance, is not a good sign, nor the gradual slight scoring that the inlet cam had. I have a 264 inlet cam to put on at some point, I'll change the inlet lifters then.
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So you are not seeing any oil buildup in your throttle body? There really should not be much at all, with proper pressure or not. The tick is something I have tried repeatedly to figure out and have not as of yet. From the sound of peoples' experiences, it must just be some innate behavior. Both of the 318iS's I have owned tick loudly. Personally, I think the injectors play a big part in it.
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Hi bmwman, if you recall I'm running ITBs not a signle TB; but no, I don't see much oil coming off the rocker breather. I should be seeing some I'd imagine the way its been used; on m44s I've replaced the recirc valve in the past when they start to recirc oil too much and consume oil/foul up the inlet, I seem to have the reverse problem with mine.
tbh I'm a bit surprised at all the alternative theories, although I welcome the input and like the food for thought. I've taken the scored cam, lifter tick and not much recirc'd oil as pretty conclusive evidence that oil pressure is a bit low at the inlet side of the head. any other theories must be a fair bit less likely.
I don't believe its innate behaviour as such, but does seem to be pretty common on the older engines; I don't often see these problems with later cars. I'm interested to see what impact the work I'm going to do on the oil pump pickup and spring etc will have. I'll pop some new tappets in soon too.
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Yes, I am interested to see your results. The tick is annoying, regardless of whether or not it is harmless, and I would not mind ridding myself of it.
Where to you have the PCV system routed to? Did you make a common vacuum system between the 4 runners post-TB or what? Where does the valve cover connect into the vacuum system?
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yeah i have the ticking noise, and it ONLY game after i rebuilt the head... its also intermittent, and i believe its starting to spread to a second lifter. I was going to replace them, but at 15$ each for 16 lifters, it seemed like an unnecessary cost as all of them checked out to be fine. perhaps it is the lifter not holding oil and its releasing it to fast causing the upward stroke of it to run insufficiently lubricated? I'm not trying to argue lack of oil pressure I'm just throwing out food for thought, as i too would like to solve this problem.
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ok so a little update. Have replaced my later e36 BMW tappets (the lighter ones) for some new vw ones. noise is still there. sadly it seemed if anything to be a bit quieter on the old tappets, though hopefully the new ones will settle a bit. Also changed the oil pickup, couldn't get to the spring sadly with just the lower sump off and the weather's terrible so that will wait.
Anyone know if the spring assembly etc can be replaced with just the upper sump pan off?
I'm going to fit an oil deflector under the crank when there too, if the problem remains then I'll change the whole lower timing case and oil pump rotors.
bloody cars.
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bmwman, yeah I do have a common vacuum rail across all 4 bodies, but I don't use this for crankcase venting, the rocker breather is simply attached to the intake plenum. I have wondered about the pressure difference between the plenum (before the throttle butterflies) and the crankcase, maybe I would be better off running it into the vacuum rail and using a valve... opinions?
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Was your chain and every single one of your sprockets new when you rebuilt it?
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Hi nick, top sprockets and idler gear are original as they were as good as new; everything else is new. But I'm pretty certain the noise is not from the chain, it's the inlet tappets.
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im just about to start putting my engine back together, would you recomend I fit a washer?
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Anyone know if the spring assembly etc can be replaced with just the upper sump pan off?
You must pull the upper and lower pan.
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yeah sorry sheepdog didn't make myself clear, i realise the lower pan has to come off to get the upper one off; what i really meant is is that all? Is the spring etc accessable from underneath with the upper pan out of the way or will i need to pull the lower timing case? Was tempted to try the spring before changing the whole lot, but am still undecided as to whether to go for the whole lot in one go.
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yeah sorry sheepdog didn't make myself clear, i realise the lower pan has to come off to get the upper one off; what i really meant is is that all? Is the spring etc accessable from underneath with the upper pan out of the way or will i need to pull the lower timing case? Was tempted to try the spring before changing the whole lot, but am still undecided as to whether to go for the whole lot in one go.
You should be able to slide the upper pan to the side far enough by lifting the motor a bit and get to it.
You can see it here...
The clip is visible when the pan is off.
(http://www.realoem.com/bmw/diagrams/a/v/0.png)
Here is what it looks like with the upper pan removed (looking up at it), the spring is in the hole at the upper left in this picture. Left side is the front of the motor obviously.
(http://www.m42club.com/images/pumpsuck/block.jpg)
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Thanks Sheepdog. Since changing the tappets the noise is actually quite a bit worse than before; it comes and goes a bit, but is pretty noisy. I'm now contemplating replacing the oil pump this weekend. Any opinions on whether its necessary to replace the lower timing case when there? My method was going to be to undo engine mounts, lift engine as high as I can, remove lower and upper pans, then take off timing chain, loosen cyl head and undo lower timing case. My rear crankshaft seal seeps a bit, so I'm tempted to pull the engine and do that while I'm there; although i'm not too worried about this as its not major. It might make this a lot easier to have the engine on a stand though. I only have a weekend, and that includes driving to and from my folks' place which has the garage and block and tackle that I'll need. All this will be on the back of fitting the tappets to my car and replacing 318-is' headgasket last week. I also have £200 ($400) of tax and around £6-700 ($1400) on insurance to pay this month; and have just spent $200 on rear tyres. Not too happy with my car at the moment.
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Thanks Sheepdog. Since changing the tappets the noise is actually quite a bit worse than before; it comes and goes a bit, but is pretty noisy. I'm now contemplating replacing the oil pump this weekend. Any opinions on whether its necessary to replace the lower timing case when there? My method was going to be to undo engine mounts, lift engine as high as I can, remove lower and upper pans, then take off timing chain, loosen cyl head and undo lower timing case. My rear crankshaft seal seeps a bit, so I'm tempted to pull the engine and do that while I'm there; although i'm not too worried about this as its not major. It might make this a lot easier to have the engine on a stand though. I only have a weekend, and that includes driving to and from my folks' place which has the garage and block and tackle that I'll need. All this will be on the back of fitting the tappets to my car and replacing 318-is' headgasket last week. I also have £200 ($400) of tax and around £6-700 ($1400) on insurance to pay this month; and have just spent $200 on rear tyres. Not too happy with my car at the moment.
The housing/case must be remove to access the pump gears, but it also forms the front half of the pump itself.
Remove the crank bolt before removing the engine. Unless you have the proper tool and help, you will not get the bolt off while out of the car.
Another tip, unhook the radiator shroud and slide it towards the engine, then slide the radiator out. This will allow you to remove the shroud and make fan removal 100 times easier.
Gasket-wise, you need a bottom end kit, water pump, water neck, profile gasket, and upper timing chain cover gaskets. I re-used my valve cover gasket. Get some spray on gasket glue, it will make the timing housing much easier to put on.
With all those bills, I would hold off and get the money for everything before starting. Then go in and replace everything, chain, housing, pump, sprockets, tensioner, idler... This way everything in there is fresh. Let it be and just enjoy driving it for a while. You are not likely to hurt the engine, many cars have this issue, not just the 318.
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When you say thatthe lower timing cae forms the front part of the oil pump itself, what do you mean? I've never dissassembled the lower timing case, but thought that the casing was simply a casing and the rotors, spring, valve etc were the important bits. Should I change it? I'm not too keen to have to get in there again, I'm pretty keen to resolve this in one hit but its a lot of money for a new casing.
As for engine dissassembly, I've had m4xs apart quite a few times dude, crank bolt etc is no problem. I don't have a radiator shroud, electric fan for me! Also my engine is new, so all timing chain parts etc are 6 months and around 10,000 miles old, I will only change what is essential to change (profile gasket, head bolts, both sump gaskets). Only thing that I'm not sure of is whether I can simply undo the engine mounts, hoist the engine up using block and tackle and give myself enough clearance to remove the upper sump and fit an oil deflector etc.
iirc the engine can be lifted a fair bit with the exhaust and box still fitted. if not, might be a bit tricky.
The reasons for being so concerned are pretty simple. My engine and car in general is worth a lot of money, and I want it to run properly after all I've put into it. This year I'm likely to do a load of miles, and do some european driving and probably a ring trip as well as some track time; it must be on top form. I also have a new wilder profile inlet cam to go in and I don't want to score it with insufficient oil supply etc. Also the noise is bloody annoying, and with the amount of mileage I do I simply can't put up with this noise. I didn't do the oil pump when changing engine because I'm an idiot; I decided that it was working fine and knew my oil pressure was fine last time I had it tested, so left it alone. In hindsight, that wasn't wise, especially as I had had a cam whirr fom the inlet side of the head since I'd owned the car. For the same reasons I won't put solid lifters in (unless I absolutely have to); I want to get to the bottom of the problem and fix it properly, not work around it. good find though!
Cheers for the suggestions and advice
Tim
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I guess we'll have to wait some more before we can finally see a video of the 2.1 ITB M42 :P Good luck with finding your problem.
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When you say thatthe lower timing cae forms the front part of the oil pump itself, what do you mean? I've never dissassembled the lower timing case, but thought that the casing was simply a casing and the rotors, spring, valve etc were the important bits. Should I change it? I'm not too keen to have to get in there again, I'm pretty keen to resolve this in one hit but its a lot of money for a new casing.
The gears sit inside the timing housing and a cover place forms the back half.
If you have oil slipping through on the sides you will lose pressure just as if the gears themselves are worn. Given that the housing is aluminum, that is most likely the worn part anyhow.
This is the backside of the timing housing minus the gears.
(http://www.m42club.com/images/pumpsuck/IMG_3941.jpg)
With the outer ring gear
(http://www.m42club.com/images/pumpsuck/IMG_3926.jpg)
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Thanks that's really useful. Makes a lot of sense. If I don't have time to pull things this weekend (I don't think I will), I'll order a new lower timing case next week.
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wait....why are you getting a new case?
I have to put the oil valve in tmr, should i use a thin washer to put more pressure on the spring? I also read that there is a spec for the lenght of the spring
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wait....why are you getting a new case?
I have to put the oil valve in tmr, should i use a thin washer to put more pressure on the spring? I also read that there is a spec for the lenght of the spring
Where did you read about the spec nick?
as for the timing case, read this bit from sheepdog earlier on in the thread:
If you have oil slipping through on the sides you will lose pressure just as if the gears themselves are worn. Given that the housing is aluminum, that is most likely the worn part anyhow.
sounds like wise advice to me. will see how this wknd goes and if i dont find the time (car is not really a priority right now) then I'll order a new timing cover. I'd examine your existing one before splashing out however; a luxury I don't really have.
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its like 84.4mm, or something. its in the repair manual
shim no shim?
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I don't know nick, wish i had the answer to that one myself!
I'm looking into trying some cam carriers and cams that are known to be quiet in my car to see if i'm losing pressure through wear there, as well as changing the oil pump. I'm going to leave the lower timing case for now and take my chances. I know that (maybe 20,000 miles ago) I had good oil pressure at the filter housing. I've just set up my block and tackle and cleared some room ready for possible engine removal or whatever. Really want to get this problem nailed now, will be a few weeks though due to other commitments.
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my new spring was at least a mm longer then the old one so i left it out
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Ok well I've finally got onto working on my car today. Have no tappet noise now, changed the inlet cam carrier, inlet cam for a 264. Tested oil pressure and it is very good indeed, so haven't done any work on oil pump area. That will wait til I pull the engine - will leave that til the summer. With stethoscope to the rocker all is nice and quiet.
Sadly I have a pretty major unidentified ticking/tapping noise still remaining that I think of late I'd been confusing with my previous lifter noise. Sounds too major for injectors (and I've tried unplugging one injector at a time and can't identify a particular noisy injector) but is coming from that sort of area. I've had the ITBs apart but can't see anything. Spent all day on this problem, am out of ideas. Am going to pay someone to fix this i think. Have spent so long on this today without luck :( I'm pretty worried about it, but it doesn't seem like its coming from the engine itself. It's a big old noise though and i'm not sure whether I should keep on driving the car or not.
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sticky valve(s)?
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You have good oil pressure from the pump and lack of lubrication to the inlet cam bearings (scoring) and lifters (noise). You mention being able to remove the valve cover with no oil blowing from that area (again lack of lubrication). The lifters are quiet in another car (not lifters) and two sets of carriers rule them out. Scoring may mean something went through there.
Is oil present around the cam and/or lifters indicating sloppy tolerances. If not the oil just isn't getting there. All this says:
1) clogged or partially blocked passage(s)
2) misalignment of the block/head gasket/oil pump cover/head/carrier interface.
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I'm not really up on fuel injection but was curious as to whether the injectors tick when they open, close, or both? At what point in the 4-cycle scenario do these ticks occur? That may help in determining if they are the culprit. With throttle bodies is the sound louder or the same?
What was different with the carrier that fixed the intake side?
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ah didn't notice these replies. d clay there is plenty of oil pressure out of the valve cap, i don't think i said that there was a prob there - either that or just me being depressed about the damn car. i questioned whether enough was coming through the breather, on inspection it was fine. scoring on inlet cam was strange, but that was there before i owned the car, so who knows. tappet clearance is spot on now and tappets are silent.
i still have a pretty major tapping noise, getting worse and worse. i've ran it to a local garage who have no ideas either. i've just built up a new late spec head with some re-lapped valves and new stem seals etc that i'm going to stick on, hopefully tmrw, will also take it to bmw specialists nearby. i'm hoping when i tear it down i'll find the culprit. i've considered whether its little ends, as i'm not 100% what they sound like, but seeing the engine is 10k miles and 6 months old and built by an engine shop i trust i'm not convinced. don't have many other ideas though.
as for injector noise, injectors make noises at different frequencies depending on the fuel injection system. e30 m42 fires the injectors in alternating batches (1+3, 2+4). i don't know the standard number of squirts per cycle. mine on MS did 2 squirts per cycle, alternating (to minimise pressure drop in the rail). injectors can tick on opening and closing, or just on opening.