Replaced engine mounts, now engine sways
 

I had the engine mounts replaced yesterday on my 83 300D Turbo. The driver's side was deteriorated, and started a coarse deep vibration at idle that went away once throttle was given. Other than that, the engine has always idled pretty smooth. Now it has a wide oscillation/sway - not violent but pronounced and it makes the whole car sway side to side at idle. I took it back to the indy, and he double-checked the tightness of all the bolts, and even backed the mount-to-body bolts out and re-tightened them. I bought genuine MB mounts. The one thing I can see is that he screwed up the engine shock mount, and it is pulled through (in fairness, it was just about shot anyways, but now it is definitely torn loose). Would the engine shock mounts make that much difference in idle? It is worse once the engine is fully warmed, but it is still pronounced even when cold. I tried adjusting the rack dampener pin, and it doesn't seem to affect it unless I loosen the bolt and it gets worse. Any input?

engine shocks dampen the movement. Have you adjusted the rack dampner pin or replaced it?

new engine shocks are pretty expensive. $52 for the mount and then $51 for the shock.. I replaced my engine mounts and both shocks and mounts... maaan did that suck my wallet dry

I need to replace the rack dampener pin, as it is the old style - but the engine was fine before. The engine mount suddenly went to crap Tuesday - fine one day and vibrating badly the next - I saw the old one and it went to pieces.

Any chance there is an air leak down by the fuel inlet where the plastic filter is. Jacking up the Engine to change the Motor Mounts could have disturbed the Fuel Hoses there.
It is cheap to find out. replace the 2 pieces of 5/16 inch fuel hoses and see if the Engine is smoother.

An engine shock won't dampen anything unless it leaks!!!

The eng shocks dampen the side to side motion of the engine, especially when turning it off.

You lost me there, unless what leaks? :confused:

Charlie

You know, I noticed a couple tiny bubbles right at the 90 of the primary - I will check that tomorrow afternoon.

Don't worry about qwerty. He's acting like one of those guys who's trying to be a smart aleck. It's like the whole motor vs. engine thing, I know that technically, it's not a motor under our hoods, but most of us are not gonna harmfully chastise someone and not answer their post just because they said they had "motor trouble". We're all in an automotive forum and know he means dampen in the mechanical sense of absorbing a shock, and not in the sense of something having water on it.

Qwerty, is this you?
http://failblog.files.wordpress.com/...aphy-fail2.jpg

Your original post pretty well indicates that the engine shock was trashed. I've never changed mine but plan to. If you search the forum, you'll find the posts vary from a new shock having no effect to completely curing engine shaking problems. Do the low cost items first and the shock last.

Please post what works.

OK - here was the issue - it turned out to be a bad injector. I've had an injector that nailed when cold, and even nailed a little occasionally at mid-throttle. I cleaned it a couple times, and it would improve for a day or two then go back to its behavior. I got a single known good injector and swapped it in, and the nailing went away, and the idle improved IMMENSELY (and everything has gotten better - more power, better fuel economy - that one injector was truly the turd in the punchbowl). The only time the idle is noticeable is after a long drive, and I feel that the rack dampener bolt is the issue there (it is the old style).

your lucky you didnt get the HOT rough swaying idle

I'm in the same boat. Replaced engine mounts, tranny mount, engine shocks, and rack damper pin, did valve adjustment, ran some diesel clean thru, and it still shakes. Please forgive the naive question, but is there an easy way to test / fix the injectors? It's not too bad, but I'd like it to be better.

Thanks

The right way is to take them out and have them "pop-tested" where they are checked for spray pattern and pressure (they should start injecting at 135 bar for turbo engines). My one bad injector literally sounded and felt bad, had a distinct heavy pinging/springy sound if you listened to the body of the injector compared to the other four.