M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => Engine + Driveline => Topic started by: Chema GB on August 05, 2024, 06:50:30 PM
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Hi guys, I would like to comment on one of the main problems I have with my 318is and I am waiting for your help.
The case is that I have had the car for 3 years, and at the beginning sometimes in winter when I started it, the chain rattled for about 2 seconds.
The noise in particular is the one at the beginning of this video:
https://www.youtube.com/watch?v=5vAx-XkHej8&t=597s
The question is that it started to make the noise more and more often, and nowadays it sounds if the car is stopped for 1 week (before I used to use it the same way and it didn't make it).
That's why searching in forums, videos, etc. I saw that it was a recurring problem in the M42 caused by the chain tensioner, or otherwise it was something normal as the tensioner was unblocked and hence the noise the first few seconds.
Therefore I checked the following things:
-Chain tensioner: I had already fitted the one from the M44 which was the new BMW reference as the one from the first M42 was giving problems. Even so, I replaced it with a new one and it is still the same.
-Oil viscosity: I have always used 10w40 oil even when it hardly made any noise. Change oil to Motul 10w40 + Liqui Moly ceratec (previously washed with Engine flush). Still the same.
-Chain: The car has 114.000km. The mechanic told me that the chain sounded a little bit, a scraping at about 2000rpm before opening the big throttle. I don't know if it could be wear but I would be surprised with so few kilometres (and with good maintenance).
-Oil pressure: the pressure sensor has been checked and is working. It would be necessary to measure the pressure with a pressure gauge, which I still have to do.
In short, it's a problem that is bothering me and I don't know what it could be, because the problem has been getting worse over time.
I hope someone can help me hahaha
Thank!
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I'd guess (and hope) you just have a few stuck lifters, based on that video. The early M42 was pretty infamous for that, in fact it continues to be a BMW problem, I replaced a bunch in my N52! I'd be tempted to try a slightly thinner oil to see if that helped with the problem. Mike.bmw notes a similar problem in this thread (http://www.m42club.com/forum/index.php?topic=19684.0). Either Shell Rotella T6 5w40 or Liqui Moly Lifter Additive might have done the trick. I've used Rotella T6 myself and will certainly vouch for its quality. Liqui (Lubro) Moly makes all sorts of wonderful stuff as well.
I'm not sure what your build date is, and I don't want to make you worry, but the early M42 motors also have some known problems with the cam idler pulley bearing. Usually the bearing will fail, but in severe cases the mounting boss can be torn off the inner cam chain housing case.Here's a good example of that failed idler bearing from bmwman91 (http://www.m42club.com/forum/index.php?topic=13574.0). The later M42 (and M44) were upgraded by BMW with a deflection rail to solve the problem. Check out this build thread at GRM (https://grassrootsmotorsports.com/project-cars/1991-bmw-318is/project-bmw-318is-m-parts-connected-m-part/). I think that was around late '92 build dates? If you have the early E30 motor, I'd check that bearing & idler gear immediately, with an endoscopic camera or likewise.