I finally got around to changing the right side engine mount in the 300D tonight. I did the other side a year or more ago, but never got around to the other one.

Had to jack the car up, no way to get to the top bolt from above, it's directly under the turbine on the turbocharger! Just barely enough room for a 19mm socket on a swivel-head 3/8" drive ratchet.

Amazing difference! The idle was better after the left side mount was changed, but after riding up to Indianapolis in my brother's SDL for the Brickyard, I decided I needed to do something about the rough idle in mine.

Funny, now it sounds and runs just as quiet as the SDL, doesn't thump when I shut if off, I can actually hear the road eating my tires off (I was inspecting the front suspension when I decided to change the mount -- new tie rods and a drag link get ordered tomorrow afternoon....). Quite a joy. It shook so bad the sunroof headliner buzzed, now it's dead silent in the car!

Don't put this job off, the difference will make you think you are in the worng car!

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Heck that buzzing noise is nothing compared to the donor car I drove home a couple of weeks ago. The hood and fender vibrated at least a half an inch at Idle.

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1984 280SEL, 62,000 miles
Euro model in the USA
1983 300D (Totaled out 10/2004)
New Factory Mint Green paint
Palomino int
1982 240D (Steak dinner for two)

^^Do engine mounts really effect idle - itself?

or are the vibrations just dampened?

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anybody? ^^^^

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The mounts don't do anything to effect the idle. They just dampen the movement of your engine along with the engine shocks. New motor mounts will lessen the shake, but you need to make sure your valves are adjusted and your rack damper bolt is adjusted properly for a smooth idle (among other things of course).

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Chad
2013 Jeep Unlimited Rubicon
OBK#44
"Pleasure in the job puts perfection in the work." - Aristotle (384-322 B.C.)

SOLD
1985 300TD - Red Dragon
1986 300SDL - Coda
1991 - 300TE
1995 - E320
1985 300CD - Gladys
2006 Nissan Pathfinder LE
1998 Acura 3.0 CL

It just dampens the effect of the engine idle. Engine mounts are a cushion to soften the feel of the engine!

My bolts are a hex bolt on the bottom and I didn't see a nut on top, 19 MM or otherwise?

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Save and enlarge for explanation of financial crisis!

http://www.mobile-phone-solutions.com Advice on cell phone signal antennas and amplifiers.

there's an 8mm hex bolt that holds the mount to the mount arm from underneath (through the hole in the crossmember) and 2 - 6mm hex bolts that hold the mount to the crossmember from the top. I used an "L" allen key to remove those.

This was for a w123. The w124 must be different.

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Chad
2013 Jeep Unlimited Rubicon
OBK#44
"Pleasure in the job puts perfection in the work." - Aristotle (384-322 B.C.)

SOLD
1985 300TD - Red Dragon
1986 300SDL - Coda
1991 - 300TE
1995 - E320
1985 300CD - Gladys
2006 Nissan Pathfinder LE
1998 Acura 3.0 CL

Whenever I get a new w123 diesel, the motor mounts and the valve adjustments are two of the first things that seem to be done. It makes a tremendous difference in my enjoyment of the car (especially at idle); my mechanic states that the motor mounts are usually good for three years. We'll see.

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- Brian


1989 500SEL Euro
1966 250SE Cabriolet
1958 BMW Isetta 600

Well , yes and no.
I used to change my motor mounts at least once every two years.
Shortly after I put a new motor (MB supplied compete motor), the mounts are still good after 6 years. one reason is total lack of any oil leaks from this motor and also every time that I change the lower, see through, in line fuel filter I pile up a ton of rags under the thing to absorb all the spills, one thing that really kills these rubber mounts.

Vahe
240D 77 350K