SOLVED - Engine rattle on startup, timing chain rattle on low rpm driving
Thread Starter
Junior Member
Joined: Nov 2024
Posts: 47
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GLK350, SL500 (R230), E55 (w210)
I have a C350 2013 (M276) with startup rattle as well, and my engine also falls under the "replace chain tensioner and install check valve" category.
Might try this mod, since it fixed the startup rattle for you.
You still haven't replaced chain tensioners and installed check valve, right?
Another suggestion I got from a retired Mercedes mechanic was to try thicker motor oil.
Might try this mod, since it fixed the startup rattle for you.
You still haven't replaced chain tensioners and installed check valve, right?
Another suggestion I got from a retired Mercedes mechanic was to try thicker motor oil.
Unfortunately the warm-startup rattle is due to the tensioners losing pressure and needed 1 or 2 seconds to pressurize again.
MBWorld Fanatic!
Joined: Sep 2015
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2013 glk 350
Does thicker oil help reduce noise ? What oil? A mechanic recommended I try a 1/2 qt of Lucas just to see if noise is reduced , I still have not checked pressure my noise is all the time now .
MBWorld Fanatic!
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From: New Hampsha
'17 GLS450, '14 GLK250, Grandpa's Roadster
Newbie
Joined: Jul 2025
Posts: 13
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2013 C350 AMG Sport+, 2006 ML320
Switched to 5w40 yesterday (from 5w30), let's see how it does. It does feel different when driving.
From what I've read it might be the tensioners, or it could be something with the camshaft adjusters that cause rattle.
Local mechanics told me it's the timing chain that might be worn.
Retired Mercedes mechanic was certain it could not be the chain in any case, said it could be the tensioners.
Car has 172.000 km on the clock.
My startup rattle is on
- cold startups
- warm start, after it has been off for 15-30 min
& always goes away after 2-3 seconds.
It does not rattle when just turned off and turned on again in less than 15-30 mins after turning it off.
Last edited by gbm; Jul 25, 2025 at 01:12 PM.
