2009 w211 M272 E350 4MATIC Cold Morning Start Noise
12-30-2022, 05:54 PM
#1
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2009 w211 M272 E350 4MATIC Cold Morning Start Noise
Please view the 1 min. Video attached at the link below from start to end.
Initial noise is Key turned at Position 3. At 25seconds, I turn on the ignition. This only happens on cold morning starts. Before I head to the shop, I need to know what all can be the reason for the noise. I got a complete oil and filter change done today. Shop noticed nothing. Car runs smoothly and quietly when warm.
There is one way I eliminate the noise every morning is double Start the car in the morning. 1st start-shut off in 2-3 seconds and then start a 2nd time and there is no noise.
Initial noise is Key turned at Position 3. At 25seconds, I turn on the ignition. This only happens on cold morning starts. Before I head to the shop, I need to know what all can be the reason for the noise. I got a complete oil and filter change done today. Shop noticed nothing. Car runs smoothly and quietly when warm.
There is one way I eliminate the noise every morning is double Start the car in the morning. 1st start-shut off in 2-3 seconds and then start a 2nd time and there is no noise.
Last edited by Oracularman; 12-30-2022 at 06:37 PM. Reason: Video link
01-02-2023, 07:31 AM
#2
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Location: Melbourne, Australia
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2010 ML550 VIN WDC1641722A564750, 2010 B180
I'm assuming that the noise was there before the oil change. There's plenty of evidence to suggest that its a stretched timing chain issue. The common symptom is noisy on start up until oil pressure builds and this engine is infamous for that. Listen to the top of the rocker cover at the front of both banks with a screw driver handle pressed to your ear. I doubt the noise is anything else such as an idler or anything associated with your serpentine belt but it pays to check that. Remove the belt, start it when cold and see if the noise persists. At worst you can rule this out.
I assume you haven't got a check engine light on the dash. Get it scanned in any event. The M272 engine has this problem up until a certain build date (in theory). Find your engine number, and then search for the Mercedes Star Bulletin that will tell you if your engine number falls within the specific engine number ranges that had this problem.
If it falls within the range, or even if it doesn't, is sounds like a stretched chain which could be caused by the chain itself stretching or one of the sprockets it runs off having worn usually associated with the V6s balance shaft. It might also be a cam position sensor being faulty (doubtful) as you'd get a check engine light for sure.
There's plenty about this on the W211 forum and Ive seen alot on the W164 forum which uses the same engine so do a search and you'll most likely find the bulletin and plenty of other experiences. Search timing chain and balance shaft issues M272.
I assume you haven't got a check engine light on the dash. Get it scanned in any event. The M272 engine has this problem up until a certain build date (in theory). Find your engine number, and then search for the Mercedes Star Bulletin that will tell you if your engine number falls within the specific engine number ranges that had this problem.
If it falls within the range, or even if it doesn't, is sounds like a stretched chain which could be caused by the chain itself stretching or one of the sprockets it runs off having worn usually associated with the V6s balance shaft. It might also be a cam position sensor being faulty (doubtful) as you'd get a check engine light for sure.
There's plenty about this on the W211 forum and Ive seen alot on the W164 forum which uses the same engine so do a search and you'll most likely find the bulletin and plenty of other experiences. Search timing chain and balance shaft issues M272.
Last edited by BlackML550; 01-02-2023 at 07:58 AM.
