W124 Engine Vibration Problem? - PeachParts Mercedes-Benz Forum

lpozzo · #1 09-30-2013, 01:52 PM

Hi,

I have a 1990 300D (2.5TD) with 165K miles and I am experiencing vibration/rattle and knocking noise when decelerating(below 20mph to full stop) and when car is in reverse gear.

Engine usually is fully warmed up(80c) and I experience vibration especially on driver's side area. It seems almost like the engine is out of sync.

Could it be the accessory belt tensioner shock? What about the motor mounts? I appreciate any insights or things I can test to find the problem. Thanks.

Louis

lpozzo · #2 10-01-2013, 08:26 AM

I called a MB Dealership and it seems that the belt tensioner shock is about $60 so it might be worth replacing and seeing if it solves my problem.

The MB dealership quoted me $120 per motor mount. I also found them on ********az for $44. Does anyone know if they are the same brand/manufacturer? Thanks.

VA-Merc · #3 10-01-2013, 08:47 AM

I have an OM603 engine...but I will speak from experience...don't get the cheap aftermarket motor mounts if that is what you are looking at...you will do them again within 2-3 months. Lemfoerder I read somewhere is the OEM supplier...they carry them on this site. A little bit more pricey but worth it so you don't have to do the same job twice.

zorecati · #4 10-01-2013, 08:53 AM

Quote:

Originally Posted by VA-Merc

I have an OM603 engine...but I will speak from experience...don't get the cheap aftermarket motor mounts if that is what you are looking at...you will do them again within 2-3 months. Lemfoerder I read somewhere is the OEM supplier...they carry them on this site. A little bit more pricey but worth it so you don't have to do the same job twice.

I just replaced my mounts on my 603 with Lemfoerder. They were 70 bucks a pop. Agreed with not buying the cheap stuff on mission critical parts like mounts.

Double check but i believe these are correct for your car.

http://www.pelicanparts.com/catalog/SuperCat/3308/MBZ_3308_ENGMIS_pg1.htm#item5

lpozzo · #5 10-01-2013, 01:41 PM

Thanks for the guidance. Do you think that my problem sounds like an engine mount issue? What do you think about also replacing the transmission mount as well?

Is there an engine dampner/shock also for my car? Thanks.

sixto · #6 10-01-2013, 06:59 PM

The engine mounts contain oil so they provide the damping function of separate shocks on older MB Diesels. It's easy to check the condition of the mounts - there's a flat spot on the edge of the mount above the crossmember. There should be a gap of at least 13mm between the flat spot and crossmember. The FSM shows how to make a go/no go gauge to measure the gap. Basically, if you can stick a finger in the gap, you're good.

The belt damper absorbs the jolt of sudden loads such as when the AC compressor engages. It does nothing while the engine is running in steady state with the AC compressor engaged or disengaged. I suppose a problem with the compressor could cause engine jerkiness but the Klima relay should probably pick up on this and open the compressor clutch.

Sixto
87 300D

vstech · #7 10-01-2013, 11:15 PM

vibration on decel, or reverse is going to be from the passenger's side mount. get a QUALITY impact wrench and an IMPACT socket set, and a long extension, and an impact universal joint and it takes two seconds to remove the bolt holding it in. then just gently jack the motor up off the mount, and remove it, and install the new one.

chazola · #8 10-02-2013, 05:52 AM

Sounds like an engine mount, especially at your mileage. Another easy way to check it is to stick a finger in there- if it's good it should be easy to put your finger (unless it's really fat

) between the bottom of the mount and the frame.

lpozzo · #9 10-02-2013, 08:32 AM

Hi All,

Thanks very much for the guidance and test I can perform. I will check the gap on the engine mount.

The vibration definitely occurs as soon as I start deceleration, or let go of the gas pedal and at times even occurs at idle when car is in gear. Thanks.

Best Regards,
Louis