I have read many posts here about the engine mounts....but I cannot determine if mine are bad. I have allot of vibration at idle and it contiunes as the engine speeds up although it does lessen some but I think it is just because the RPMs are up....
It is so bad, at idle, the hood of the car shakes and things rattle inside the car....
I looked at the mounts and I can't tell much....I did notice that when I put the car in gear the engine tilts a little so I held the brake and gave it some throttle and it lean some more....but it did not ever leave the mount......is there supposed to be play in the mounts or should they be solid and hold the engine steady during a load?

I have read about "rack dampers", "Diesel Purge", Engine Shocks" and other things...but frankly just don't know where to start....
Any advice would be greatly appreciated....
Brian

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1995 E300 Diesel
1994 E320
1999 C230K
1994 S500 W140
1990 300 SEL

Our 100kmi 190E engine would make knock sounds on startup, a rhythmic thumping feel when backing up at fast idle, and engine noise would increase slightly when the suspension would compress on road undulations. The mounts also failed the clearance test, which might not be valid with yours. On removal, I found they had collapsed about 1/2" or less compared to the new replacements, and the difference in engine behavior was dramatic. I replaced the engine mounts, followed by the tranny mount and all exhaust hanger rubber.

As your engine is larger and much heavier, with a lot more low-end torque, I would expect mounts have deteriorated.

Steve

The engine mounts usually look good. if they are slightly cracked on the "sides" then they are most likely bad. If you have engine shocks, replace as well... I think the shocks make the greatest difference in the shaking on the car. you can also tell how bad the engine mounts are by looking at the engine fan on the fan shroud.. compare the amount of space available at the bottom of the shroud to the top... again, spend a couple extra bucks and get the engine shocks, engine mounts and engine shock bushings... you wont regret it!

Newer style mounts have a min height before replacement.

Just how "loose" the engine feels pulling laterally against the valve cover and how the engine sits- I can tell. The mounts have narrow sides and when the engine mount collapses, it becomes solid-transmitting the side to side movement into the body.
yes, the dampeners can make a big difference.

Michael

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Michael McGuire
83 300d
01 vw A4 TDI
66 Chevy Corsa
68 GMC V6 w/oD
86 300E

For me the brake and gas it test is a very good indication of the mounts being bad. None of my engine mounts came of their perches. The Benz mounts don't fail the same way some other cars do by ripping apart. If the engine twist a couple of inches when you rev it I would say their bad.

Your hood shaking is a good indication to me that their gone too. You'll be amazed at the difference when you swap them out.

If they are truely in sad shape...

Check the flex-disks and rear mount. 2 mounts and new flex disks made my W124 feel like a completely different car.

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Michael McGuire
83 300d
01 vw A4 TDI
66 Chevy Corsa
68 GMC V6 w/oD
86 300E

I honestly have to say that I cannot tell you what is wrong witht he car yet with the info provided..

BUT: If you have had the car for years OR just bought the car and don't know the condition of the engine mounts, replace them they are rather inexpensice compared to the engine shocks.. ($100 engine shock pair v.s $25 engine mount pair)

if this fixes the problem, great.

before you do this, check your idle speed RPM (you can use a engine analyzer from Sears $50, but you will use it often on tune-ups if you are a DIY person) with it you can check your voltage.amperage, RPM.

you will need a 8mm & 6mm Allen to replace the mounts (not the allen L shaped one. You need the Allen that comes in a socket so you can use a "ratchet wrench."

Also check your timing...
after these are in spec:

you may also have a vacuum leak, take some wd40 (some may disagree) and spray along the vacuum lines, if you get a surge, etc.. replace/tighten vacuum hose(s)

then go further into checking your fuel system (start by checking the fuel pump relay and end with the fuel pump.. (cheapest part to most expensive)

Last thing you want is to buy something you didn't need right?
I am in the middle of figuring out a similar problem, so If I find something, I will let you know ASAP.

forgot: ENGINE MOUNT SHOULD BE COMPLETELY TIGHTENED ON THE ENGINE.. NOT LOOSE.
Do the same! :-)
Good Luck.
-Rafael

From my recent experience, rough idle alone is not a good indicator. I replaced all motor mounts, shocks and dampeners with zero difference to the tune of around $300. Just a differing point of view.

Bad engine mounts
http://www.peachparts.com/shopforum/diesel-discussion/121286-bad-engine-mounts-post868339.html