1993 300E 2.8 130K

When car is in drive, there's a vibration/rumbling sound under the hood.
When car is in neutral or park, the car runs perfectly.
Would this most likely be caused by a bad motor mount?

Thanks

 

I'm hearing the same noise in my car. I looked under the hood last night and it seems to be coming from the water pump area. I thought the water pump makes a different noise when it starts going bad but I know mine is on it's way out b/c there is coolant leaking in that area and it's not the radiator (got that replaced in August).

'93 300 TE 4M (103 engine)

 

If you look at the water pump area there is a small "shock absorber" that is mounted there. It is used for the belt tensioner. This shock fails and vibrates and makes a sound that is like a diesel. Motor mounts will make a bad vibration that you would feel and idle with engine in drive. You can usually just look at the motor mounts and see if they are shot or not. Motor mounts avg. life span is about 75k-115k miles.
Motor mounts and this "belt tensioner shock" are relatively inexpensive.

Dan

 

Thanks Dan. I will look at it tonight. One more item on the shopping list.

 

Anyone know the proper name for the above mentioned shock or damper? If I were to search for this part on the Internet, what would I look under?

 

That dampener is also part of the belt tensioner! I had a tensioner go bad and it made the noise you a describing! Shop the net I got mine for about $100!! Here's what it looks like !Odds are the bearing is gone on the pulley! On the link to the left of the page is a link for the dampener and adjustment screw.

Smokie


http://rep.speedycarparts.com/parts/...nes=-12-048696