Engine noise, please help me diagnose it! - PeachParts Mercedes-Benz Forum

mpolli · #1 07-24-2017, 05:27 PM

I had a recent experience with a timing chain defect (stiff link) and the symptom was a cyclical/periodic noise with a repetition rate about 1Hz. Yours seems to have that repetition rate also. That is about the time it takes for the chain to go around once at idle. There is nothing else on the engine that revolves at that speed (at least not on my engine). Do take the belt off to make sure.

In my case I had to change the chain. Mine is a M111.

Good luck

DigitalArts · #2 07-24-2017, 06:16 PM

Quote:

Originally Posted by mpolli

I had a recent experience with a timing chain defect (stiff link) and the symptom was a cyclical/periodic noise with a repetition rate about 1Hz. Yours seems to have that repetition rate also. That is about the time it takes for the chain to go around once at idle. There is nothing else on the engine that revolves at that speed (at least not on my engine). Do take the belt off to make sure.

In my case I had to change the chain. Mine is a M111.

Good luck

Unfortunately I took off the serp belt and ran the motor only to still hear the noise. It sounds almost absolutely like it's coming from the area around the thing that makes the vacuum noise for 90 seconds after starting the car, but the trusty mechanic's stethoscope proves that doesn't make any similar noise.

If it is the timing chain, what are my options aside from replacing it? I was just on the edge of contemplating replacing this car with an e55 actually. If it will go for another 25-50k miles then I'll just deal with the noise.

It's a shame I can't guarantee that a new chain tensioner would fix it, that part looks to be about 50-60$.

mpolli · #3 07-24-2017, 06:22 PM

Sorry I am no expert on that. If it was a M111 then at least I could speak from experience. I suppose you could try the tensioner. My guess is that won't help but maybe someone else has a different opinion. I could be wrong.