Hello every one .I am new to this forum and i hope someone can help
I have a 1989 250d estate 5 cylinder om 602 without electronic control, the problem is that the engine shakes on medium throttle ,ie you over take a cyclist and and put your foot down the whole car rocks back and forth,a sort of surging if you change down a gear the problem goes, this problem happens at all speeds but does not happen in if you hold it flat out . it will start first time every time and the engine idles smoothly. The rack damper has been replaced ,the filters have been replaced ( tank gauze cleaned , pre lift pump has been replaced) . The engine mounts are worn but not to excess , the Injection pump timing is correct and there is no slack in the timing chain . the injectors have been checked buy a bosch specialist. If any one could help with this problem i would be very pleased Thank you in advance
David

David:

Transmission mount gone flat will cause a drumming vibration on acceleration, worse at high loads. So will a bad rubber mount for the center drive shaft support -- it gets soft and allows the driveshaft to "orbit" under high load.

Neither one is a big job.

I suppose bad rear subframe or differential mounts could cause this, but I'm not sure.

However, if you cannot see the angular section of the engine mounts, they have leaked out and you will have MUCH vibration under acceleration from the engine thrashing about. If they are less than 3/4" from the frame to the large rubber lip, replace them, it will make a large difference!

Very easy job with a floor jack if you don't have a turbo. If you do, it's a lift only job, I don't believe you can reach the mount under the trubo except from underneath.

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!