Rattle on Startup
 

Hey guys - I have a rattle/vibration sound occurring only on startup. It's starting to occur more often and of course the dealer has told me they can't hear it. It's actually quite loud and sounds like its coming from the exhaust somewhere near the front of the car. Almost sounds like something is loose. Anyone else experience this issue?

Thanks

I get this also. Mine is intermittent. I don't know if we are talking about the same sound but mine sounds like the timing chain is dragging on something at initial fire up.

Mine honestly sounds like an exhaust hangar is loose or something. Only occurs when i initially turn the car on though - if it was an exhaust hangar i would imagine i could hear it through certain power bands, no?

If its from the engine it is the cam adjusters.

I've heard the sound of bad adjusters in other threads. The sound I get is more metallic in nature. Could it be the heat shield?

Cam adjusters will make a metal rattle on start up when going bad.

I have this same issue, my dealer said that it can't be the cam adjusters if I don't have a check engine light on. Any truth to that?

No.

I did a lot of digging around on this and say your threads. I called both local dealers and they said they've never heard of this causing a rattle. I am going to take it in but already feel like it will be a frustrating experience and they will say they don't hear it.

I've had rattles and all 4 replaced (one at a time as the rattles happened). On a side note, I've asked my MB rep and he said it doesn't cause any damage anyway. Not sure if his word is gospel, but he is pretty forthcoming and knowledgable, plus I asked him when my car was out of warranty.

I just have to get them to agree to do the work- already over the phone i felt they were brushing me off. I have a 2014 with 13k miles, so full warranty. Is this a long turn around time? Like a week or so?

No, it's not a huge job. Every time I had mine done, I had other things done, too, but it was 2-3 days total.

Here is a video I just took. Is this the same noise? Thank you!

Same sound I have had for the past 16 months been to the dealer multiple times for it it's the cam adjusters I had them replaced still didn't fix it car drives fantastic I'm not paying attention any longer good luck having the dealer fix it basically told me it's normal it's not but not hurting anything right now I'm keeping my ears closed on start up lol was told my valve train looks great so appears to not be hurting anything in 16 months or performance either just noisy o well if they fix it let me know please

Will do. Interesting that it's fairly common, my dealer claims they have never heard of this before :bsflag:

I will let you know if they do anything but I'm expecting a lot of pushback.

That's unfortunate. My dealership fixed all four no problem.

Use 5w40 oil. Lifters bleed down with the 0w40.

I do! What’s up with that?! I just bought a 2015 507 coupe.

Don’t call the dealerships as they would have never heard of any issues or problems whatsoever with any of their cars in since forever.

You know, I have thought about doing this myself because I get the cam adjuster rattle every now and then on cold start :y

Update:

Just looked and Walmart doesn't carry 5w40 :(

They always have 0w40 on sale so I guess I am sticking with that :)

Could always look at going with FCP Euro and then oil changes become way cheap too. Been using the LiquiMoly 5w/40 with quieter results than Mobil for a year now.

Just an option and I have to admit I enjoy FCP's warranty that makes an oil change cost about $20 now.

Mine rattles on cold startup.

I use M1 5-40. I’m going to switch to LiquMoly 0-40.

TC

I’v had my Cam adjusters changed as told by a specialized mercedes mechanic. Once changed he told me the car is perfect. Took it and on the first startup the sound is back. Had the oil changed already and using 5w40. Any other idea what could be causing this otherwise?

another question would be about another sound i have. It is similar to the video below.. anyone knows what is the reason behind it?


Thanks in advance!

Is your car a Performance Pack car because they have forged pistons and they can rattle when cold.
Mine does same at exactly same revs and always has.

mine is a c63 507 edition 2014..so you’re saying there’s no harm in that sound?