[webermaster]

OK guys today after I drove my car in the morning for like an hour I drove back home, parked for like two hours and start the car again going out I hear this annoying noise coming from the engine part! So I stop and listen to it, and it seems like it is coming from the pulley part... call my shop and send them a video they told me it might be the water pump going out... then I went to another shop the owner help to spray some lubricant on the pulley belt and told me it might be the belt too dry causing the problem... Anyone know what happend here? I will upload a video so you know what I am saying.


Click the link below for the video:

 

[wadesalot]

Can't tell from your video. Typical things are certainly water pump or any of the other rotating pulleys in the system like the alternator, a/c compressor or the belt tensioner pulley. I doubt it is the belt but that is easy to inspect to look for cracks or splits. Easy way to check is to remove the belt and spin the various pulleys to see is something feels rough, or use a mechanics stethascope or long handled screw driver to put in contact with each area and listen for something unusual. Don't let someone set you up for a big bill based on just listening. This will need some investigation to get to the right problem.

 

[Eric Lam]

did u try this test?Techtips - Diagnosing Serpentine Belt Problems
i had the same noise from the belt.MB changes the belt 3 times,an alternator,power steering pump ,belt tensioner pulley and center guide pulley with shims.eventually they change the center guide pulley(272-202-14-19) again and remove all the shims.BTW all the works done to the car werent necessary .The problem was the center guide pulley only.So far so good no noise for a month.Also all the works are done under CPO warranty .so my cost is zero.

 

[webermaster]

Thank you very much!!! Which one is exactly the center guide pulley??? I guess I will have my shop take a look at it next week! Is it OK if I still drive it???

 

[Eric Lam]

google this part number 272-202-14-19.i was driving it without any issues.by any chance will the noise goes away after the engine reach operating temp.?and also you can try to spray a little WATER(only)on the belt and see the noise go away.If it does ,most likely the belt is slipping.I had no issues driving my car for days before i take it to the dealership to have it fixed.

 

[webermaster]

Thanks Eric!!! I guess I am going to buy the guide pulley first because it is not that expensive!!! Sorry to hear about all the unnecessary parts you have replaced!!! Seems like this W164's parts wore out much much faster than my old W163!!! I am starting to think I made a wrong mistake buying the W164.... : (

 

[Eric Lam]

Actually i didnt mind for all the new parts they put in the truck.first it cost me nothing(under CPO warranty)that might save me all these works later even thought i have 2 years and unlimited miles extended warranty beside my CPO.second.i did test drive 3 new loaner cars.GLK,C300 and CLA 250.thirdly MBUSA gave me $350 service credit for the inconvenience.And the most important part is.i know the truck doesnt have any major fault.best of luck to you and hope the pulley is the only culprit.

 

[20swrt]

Good isolation skills is much better than replacing parts one at a time. The way that noise sounds - the frequency seems more in tune with the belt. To make sure - spray some belt dressing while the engine is running. if the noise immediately goes away - replace the belt. Be careful. Do not spray on the pulleys.

 

[Eric Lam]

Have you locate the problem(s)?

 

[webermaster]

Hi Eric haven't got the chance to go to shop yet and also the sound disappear these two weeks!!! Also my shop is hell of busy so I probably going to drop it off maybe next week or so! Will let you know once its check!

 

[Diamondrichlb]

Any update? I have a 2011 with noise coming from the engine compartment. There's a medium pitch noise with a little grinding in it that happens when I start it up. Then just general engine noise that I can hear from 100 feet away. The service department says all is normal. I have no idea how a modern car can be built with engine noise this loud and be called normal. Amazing!

 

[webermaster]

HI there no updates yet my shop is extremely busy!!! But the sound disappear these two weeks, I did some research and it really seems like one of the supporting pulleys or the tensioner pulley causing this sound!!!