Hi fellows my car recently makes this grinding noise in the morning when it is really cold (below 35F). The noise goes away when the engine is warmer. As you can see, the noise happens immediately at the starting point of the engine, and it doesn't last. I used to have a 2007 ML500 and it has the same problem. Dealers always can't solve it because they can't hear it when I bring the car in (because the engine is hot then) .Anyone can help me explain why this happens? Thanks a lot!
Also in the morning, when just started, if I go downhill, then I can hear a cluntch noise when the transmission shifts from 2nd gear to 3rd gear. But that only happens once, in the morning. after it shift to a higer gear or if the engine is not that cold when I star it, the problem never exists . I have attached 2 youtube video, please check those if you have the same experience. I really really really appreciate your help.

For the grinding noise: http://youtu.be/fp1chyeoDgU
For the cluntch noise: http://youtu.be/F0vfgona_SI
Thanks a lot!

 

The only thing I heard was beeping ....

 

actually that happens right before the beeping, you need to turn your speeker to the maximum thought. It is actualy friction-like metallic noise, happens at the same time as the engine stars, then it goes away,

 

Cold morning crank noise. I've had it too every winter for 3 years. Normal.

 

Really? Have you ever been to the dealer? I'm worried because my friend's 2010 ML350 doesnt make such noise. This makes me think that something is wrong becasue my car is 2 years older than his.

 

Uhh, he's got a totally different engine than you (either a 6-cyl gas or a 6-cyl turbo diesel). Can't really compare.

- Mark

 

so the noise for the V8 is normal? or in another word, most V8 has this problem?