Motor mount diagnostic help.. - PeachParts Mercedes-Benz Forum

dmtinker · #1 12-04-2007, 09:12 AM

The front, driver's side of my 82 300SD started vibrating yesterday. Today when I went out to start it, the vibration was severe. It felt like someone had a jack hammer on it. (this is while sitting at idle). After it warmed up, I took it out on the road. By increasing the RPMs the vibration stopped. It is only when idling that I notice this. I also noticed that it was less severe when the car was warm. My guess is that I have a collapsed motor mount and/or vibration damper (shock?) problem. I looked at the driver's side mount and it looks like the rubber has finally collapsed. I'll post a picture later.

Do these symptoms sound like a motor mount? How hard are they to replace. I REALLY do not want to do this job in 30 degree weather but I may not have a choice. Any input would be appreciated.

vwbuge · #2 12-04-2007, 09:24 AM

I just did mine a few months ago. Not really that hard but like you said, not something you want to be doing in 30 degree weather. You can look at them and tell if they are bad. Take a look and have someone start the car or manipulate the throttle while you are looking at them.

When I did mine the passenger side was on its way south and the driver's side was completely torn in two pieces.

ahuggard · #3 12-04-2007, 09:58 AM

The job is not that hard--I did it on a 617 a couple of weekends ago in 30 degree weather. It took me about 1.5 hours to do the driver side mount and about 15 minutes to do the passenger side. If you go to the DIY section of this forum, you will find several very helpful articles.

Good luck,

Alex
85 300sd 221k

LUVMBDiesels · #4 12-04-2007, 10:06 AM

Here are some tips...

1) Get a good pair of ramps

2) Get a decent floor jack and a piece of wood to lift the engine. You need to pick it up about 2 inches to get the mounts out and in

3) Replace them in pairs and do the engine shocks at the same time

4) Get either a long piece of pipe or 2x4 to 'persuade' the engine to drop down in the right place.

It should take about 45 mintues to an hour to do both sides.

It helps to have somebody to give you a hand, but I did it by myself.

dmtinker · #5 12-04-2007, 05:10 PM

Quote:

Originally Posted by LUVMBDiesels

Here are some tips...

1) Get a good pair of ramps

2) Get a decent floor jack and a piece of wood to lift the engine. You need to pick it up about 2 inches to get the mounts out and in

3) Replace them in pairs and do the engine shocks at the same time

4) Get either a long piece of pipe or 2x4 to 'persuade' the engine to drop down in the right place.

It should take about 45 mintues to an hour to do both sides.

It helps to have somebody to give you a hand, but I did it by myself.

I live in a house with 2 women and 3 dogs.....

dmtinker · #6 12-04-2007, 10:57 PM

Here are some pictures of the mount which I think show failure

vwbuge · #7 12-04-2007, 11:24 PM

My mounts were shot. The driver's side was torn in half. I had to beat my heat shields flat with a hammer. I'm pretty sure the metal heat shields on top are supposed to be flat. If those look bent up chances are the mounts are collapsed.

dmtinker · #8 12-05-2007, 12:25 AM

You can actually see in some of the pictures that the metal is torn.

JimmyL · #9 12-05-2007, 12:41 AM

It drops the engine down to where it is actually contacting a frame support underneath. My wagon was awful before the mounts were changed.
That one looks nasty and crushed. Buy you a pair and search for a replacement procedure here in the forum.