mystery sound in my Merced 2012 c350
02-01-2023, 04:42 AM
#2
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MY'14 W212 M276 3.5NA @60kMi
mystery eng noise
Have you located the red latch to open the engine hood?
Can you find time to look at fluid levels before your engine quits. Car issues rarely heal themselves.
It sounds like water pump/belt tensioner related...
(beware of hot coolant)
Can you find time to look at fluid levels before your engine quits. Car issues rarely heal themselves.
It sounds like water pump/belt tensioner related...
(beware of hot coolant)
02-01-2023, 03:56 PM
#3
Junior Member
Thread Starter
Yes I checked all fluid levels, also the noise stops when I stop, but the engine runs fine. I took out the fuse for the secondary air pump and the abs fuse, and that noise is still there. The sound does not vary with engine speed or if I put it in neutral and rev it up
I am hoping someone here knows exactly what the sound is from It does not sound metallic , also If I park on a hill and turn off the engine , OFF , then put the car in neutral with the engine off and coast with the engine OFF , there is no sound at all, but if I start the engine as I am rolling, the noise starts right away , just like you hear in the video, but when I stop the car on the side of the road the sound stops too.
I am hoping someone here knows exactly what the sound is from It does not sound metallic , also If I park on a hill and turn off the engine , OFF , then put the car in neutral with the engine off and coast with the engine OFF , there is no sound at all, but if I start the engine as I am rolling, the noise starts right away , just like you hear in the video, but when I stop the car on the side of the road the sound stops too.
02-01-2023, 04:08 PM
#4
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MY'14 W212 M276 3.5NA @60kMi
not engine.... then tranny?
As you've proven, it's not the engine...
Then it's transmission !
Is this a 4Matic all wheel drive with a transfer case else rear differential??
What mileage and service history on this vehicle?
Then it's transmission !
Is this a 4Matic all wheel drive with a transfer case else rear differential??
What mileage and service history on this vehicle?
Last edited by CaliBenzDriver; 02-01-2023 at 04:10 PM. Reason: diff
02-01-2023, 04:28 PM
#5
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Thread Starter
it's a 2012 C350 4 matic all wheel drive. Has 118,000 miles. Transmission fluid changed at the proper Interval at the dealer . I cannot find a single reference on Google or YouTube that matches the sound in the video. It makes no noise when coasting with the engine off but as soon as the engine starts when in neutral while rolling , the noise starts and the noise stops when I pull over and stop with the engine e running
02-01-2023, 05:29 PM
#6
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MY'14 W212 M276 3.5NA @60kMi
Transmission SHOP
the question then become ...
> How does one find a knowledgeable shop for MB transmission work??
> That's a shop with practice to run ADAPTATIONS using MB Xentry computer subscription....
This maybe best answered by your trusted repair shop who has partner contacts.
You mentioned dealer service, I don't think they doctor transmission but can definitely install any rebuilt unit ready to install as part.
> How does one find a knowledgeable shop for MB transmission work??
> That's a shop with practice to run ADAPTATIONS using MB Xentry computer subscription....
This maybe best answered by your trusted repair shop who has partner contacts.
You mentioned dealer service, I don't think they doctor transmission but can definitely install any rebuilt unit ready to install as part.
