skullbox15

Been hearing a loud noise upon cold start for the last few months. Didn't think much of it until I came across this video:

https://www.youtube.co/watch?v=YeUx-_rRpeU

Mine sounds very similar, but may not quite as long/loud. Hard to tell from the recording, but this is about the best I can do without breaking out the full-blown shotgun mic:


What do you guys think? Car only has 37k on it.

AMGonFire

Been talked about many times. My car does it as well. Been doing it since I bought it. 2 1/2 years ago. It's the camshaft adjuster making that noise. Had them replaced still made the noise. 3 Benz dealers told me it's normal. Heard other m156 do it as well. Do I think it's a normal sound no but they said everything internally looked and functioned normally. I haven't had any issues and car runs great. 20k miles with that noise on cold starts.

Merc63

Drain the oil and fill it with Shell Rotella 5w40 T6, thank me later

m a x i m u s

Not normal, but my tech told me it is harmless.

AMG3.2

+1 on the Shell Rotella. Just switched and my start ups are noticeably quieter when comparing to M1 0W40.

I don't hear anything out of the ordinary OP.

skullbox15

I'm leaning towards that as well. You're not the first person to mention this and I think it makes a lot of sense.

BLKROKT

The Rotella T6 is an excellent oil, and I've also seen a big improvement in noise, but just beware that is it not MB-approved spec.

Merc63

I've been running it for two years now works great. I buy 20L at a time on sale. Use it in all my trucks.

Another thing to note, don't follow the MB drain intervals, if you're hearing start up noise change your oil. 15,000km is too long.

hachiroku

these videos sound like camshaft adjuster.

i'd recommend the same as others and try a new oil. the one time i ran mobil1 my engine was making really crazy knocking noises. switched back to motul 8100 and haven't ever heard it again.

QWKSNKE

Bottom video sounds normal to me. Top vid sounds like ****

skullbox15

I'm in FL, and saw an interesting comment from this guy in UAE that tears apart these engines daily:



He's actually recommending 10W60 for FL weather, and blames the low weight oil for the premature wear on the camshafts.

bullitt69

I've been in contact with that guy in Youtube comments, he is very helpful and knowledgeable. His videos are very interesting to watch.

It was a discovery for me that the camshaft adjusters have a part inside which can literally be installed the other way around and the adjuster will be as good as new!