Diesel Shake

[DJRACER]

Have A 85 300sd And The Engine Started Shaking Real Bad.its Idling About 800 In Drive And No Smoke.oil Pressure And Temp Good.its A Little Sluggish Off Line But Always Been That Way.could It Be A Injector Or Low Cylinder? Is There A Way To Check Both Without Taking It To A Garage?

[coachgeo]

engine mounts and/or engine shock or the tranny mount (or all of the above)finally went south.

Check your motor mounts (you are looking for a collapsed mount) they should be holding the engine up off the frame.

If they are good...come back and talk to us

[meltedpanda]

Rock can be adjusted with rack damper on back of IP. Do you have the new bolt or old style.
Sudden onset is of some concern. Fuel filters clean?
Check mounts as mentioned
let us know

[SD Blue]

If it started suddenly, you probably managed to get ahold of some bad fuel or a clogged fuel filter. If you have a source of biodiesel B20 nearby that worked the best for me. If not, an injector cleaner, such as power service or diesel purge should do the trick.

[DJRACER]

All The Mounts Look Good. It Acts Like Its Not Hitting On All 5 Cyl Until You Get The Rpm Up.any Other Ideas.it Has 170,000 Miles On It.if I Run The Idle Up To 1000rpm,it Doesnt Idle To Bad.

Originally Posted by DJRACER

All The Mounts Look Good. It Acts Like Its Not Hitting On All 5 Cyl Until You Get The Rpm Up.any Other Ideas.it Has 170,000 Miles On It.if I Run The Idle Up To 1000rpm,it Doesnt Idle To Bad.

Did it come on quickly or after any sort of event or was it just out of the blue/gradual?

This info will help us a lot in ruling out the possibilities...

[barry123400]

If you have never checked the valve clearances do it. Once you are sure that they are reasonable why not try loosening one injector line at a time to verify that all cylinders are firing or that you have a dead cylinder or a problem cylinder. Also would narrow down a fauly injector as well as a possibility. Costs next to nothing to perform the above yourself and may help you eliminate certain possibilities. I assume the idle is really rough. Assumptions are dangerous though. Keep posting as you go through things as your experience will help someone else in the long run, Edit: sometimes it is the simple things that are overlooked. SD blue has an interesting observation as a really bad batch of fuel is always a possibility. The primary reason i do not like my observation is the idle rpms are at 800. if you dropped a cylinder i would expect a lower idle to some extent. if the idle was 800 prior to the problem i would almost have to discount a dropped cylinder, on the otherhand you might maintain 800rpm with an injector fault.but just guesses really.

[mechmagcn]

My 81 300SD does this from time to time. It always has some shake to it at idle but sometimes it gets real bad (shakes the whole car). A quick dose of diesel additive usually clears it right up.

[meltedpanda]

could be sucking air as well, all fuel lines tight?