When should the timing chain be replaced?

[race2win]

So, by looking at the above pictures of my upper gears, you would say my chain set-up is OK? I got everything back together today, & although it is now running better than ever (it had lots of cracked vacuum hoses), it has this very loud rattle/vibration that I swear is coming from somewhere in the front of the engine (the car has always seemed to have this noise since I bought it). It is really bad at idle when the car is cold, & seems to quiet down a bit once things warm up, but I still can hear it at varying RPM & throttle inputs. I took a long screwdriver & touched the end to the front case so I could listen to it to try & pinpoint where the noise is coming from, & it sure seems to be coming from there. When it's rattling, it's almost like the sound is coming from somewhere near the center of the engine, on the driver side. Do these engines have a balance shaft? If so I wonder if it is something to do with that since my chain has no tell-tail signs of being bad. The car runs really good, just worried about this noise & don't want it to break & leave me stranded somewhere. Any ideas?

[jgraves]

The only complaint I have about replacing my current timing chain and all it's components, is that it is expensive.  It's going to cost me over $800 for all the parts alone.  Plus, you have to replace the head gasket to do it completely right.  The information on this thread has really given me a lot to think about.  I know I'm going to change my timing chain, because getting stuck on I95 between New Jersey and Atlanta is not something I want or need to happen.

[sennasixty8]

I just tried looking thru the oil cap and barely saw the sprockets, using a very bright LED flash light.  I could not see much past the top rail bridge under the cap.  

My new m44 tensioner was installed last week, and when the engines cold the chain racket is pretty loud.  This is my 3rd m42 e30, and is the noisiest so far.

[sheepdog]

So, by looking at the above pictures of my upper gears, you would say my chain set-up is OK?

The sprockets look great so the chain is not stretched. So long as there are no bits of chain rollers in your pan, you are fine. Those sprockets are like new.

Look at the tooth shape on this (non m42) sprocket compared to yours.
This is what a worn sprocket looks like.

See how pointy the teeth are.

[sheepdog]

The only complaint I have about replacing my current timing chain and all it's components, is that it is expensive.  It's going to cost me over $800 for all the parts alone.  Plus, you have to replace the head gasket to do it completely right.  The information on this thread has really given me a lot to think about.  I know I'm going to change my timing chain, because getting stuck on I95 between New Jersey and Atlanta is not something I want or need to happen.

My advice, find a junk yard or someone with a car they are parting out.
I got a used e36 engine for $200 and used those parts on mine.

Mileage isn't the issue, just condition. Even if you only replace the guides with used ones, it saves a bundle.

Do not use an old chain, with new sprockets or new sprockets with an old chain, they will VERY quickly wear in together and likely break the chain.


You do NOT have to pull the head to change the timing system. You have to replace the profile gasket to replace the oil pump not the chain. BMWMan91 and myself have both changed out the pump housing and profile gasket without pulling the head and ended up with no leaks. He pulled his motor, I simply unbolted one motor mount and jacked the motor up a bit. You need to pull the upper pan is why you have to do that. It's a pain, but less messy than the head.

BMWman91 and myself both blew up the oil pumps and had to replace the oil pump housing (over $300 alone from BMW). He got his parts for $50, I paid $200 for a whole engine. There are ways of doing this cheaper than you think.  Yes, new parts will last longer, but for $200 and a few hours work if you get 60k miles out of it, who cares. For all you know the rest of the engine could die before then, and considering how cheap used engines are for these, who cares.