My 95 ///M3 is having some noise coming from the front of the engine (top front part). Replaced the chain tensioner and the noise is still there, Sounds like if the timining chain is rubbing agains the valve cover (but it is not) the car has 115k miles on it, any suggestions before it goes to the dealer?

Gracias.

Where did you get the chain tensioner from? I purchased one from the dealer and had them install it and the noise was still there... they removed it at NO charge... after doing research, I found that there is a newer chain tensioner available... I called up Pacific BMW and they had it in stock and shipped it to me... I looks quite different than the stock tensioner and after I replaced it, the noise went away. Hope this helps?

Vanos unit failing. About $200 new, a Bentley manual will walk you through the replacement, but you really need the cam timing tools. The noise is the secondary timing chain hitting the valve cover between the cams. This is a good guess.

Do you have part number? Thanks.
Hoang.
I called up Pacific BMW and they had it in stock and shipped it to me... I looks quite different than the stock tensioner

I had a very similar sound at about 90K miles at idle and it varied with rpm. Sounded like the links of the timing chain hitting the valve cover. I already had the updated tensioner so I figured it was just a worn vanos.

One day I switched from 15W-50 to 0W-30 mobil 1 and it went away completely. I can't explain it but it worked. Maybe it has something to do with different hydraulic pressure in the chain tensioners due to the different viscosities(speaking out of my ass here)?

It may be a long shot, but what oil are you running?

Rich
95 M3

I've heard of similar symptoms for a bad VANOS unit--

I'd try to oil bit first though :)

I had the same symptoms and replaced the VANOS unit and the tensioners, and switched to 5W30 synthetic oil, but I still have the exact same noise you're talking about.

Good luck! I've been struggling with this problem for a long time.

Had my vanos cogs/gears replaced 2 times within 10,000 miles. The second time, the noise was louder AFTER they changed vanos parts. I bitched of course because my car was about to go out of warranty. They said they contacted BMW North America whom told them it was a "NORMAL" vanos rattling sound. I think Will Turner wrote a splurge about the same thing calling it normal. It is however worse on soem cars than others. I recently heard a 95 that had never had any tensioner/Vanos work done, I CRINGED! Sounded like it was about to come apart! The oil viscosity may have some validity since the Vanos is activated by hydraulic pressure- correct?!?

I am by NO means an expert on this or anything for that matter, but here goes....

I was looking at binh's cam kit install pics on the e36 m3 forum, namely the first one of the cam gears.

The arrangement of the gears and the oil operated primary chain tensioner between them leads me to believe that as the cam gears wear, a certain amount of slack develops in the timing chain.

When I used 15W-50, I believe the additional pressure caused by the thicker oil caused the tensioner to extend further, (since it works on oil pressure, right?) causing the chain to rub the vanos/valve cover, right between the gears.

This would explain the chain rubbing noise right under the vanos/valve cover!! So by switching to a lower viscosity oil, it reduced the extension of the tensioner, eliminating the rubbing.

This might also explain why changing the vanos and tensioner(s) doesn't always eliminate the noise since it's actually the worn cam gears that are causing the problem.

Am I nuts or what??

Rich
95 M3
Armchair "mechanic" ;-)

Originally posted by 94-325i
Do you have part number? Thanks.
Hoang.

The part number for the new style timing chain tensioner for my 95 M3 (manuf. 7/95) is 11 31 1 405 081. If replacing the tensioner, it is also a good idea to replace the gasket ring, which is part number 07 11 9 963 418.