Hi, I've got a 2002 Dodge ram 3500 V10, automatic, box truck converted to a flatbed. I've been trying to diagnose an issue with not much luck. The engine has a mild shake to it at idle and gets worse under acceleration. It does not stall, have a rough idle,etc. Recent new parts are:spark plugs and wires, ignition coils, throttle body cleaning, and a fuel pump. All done within the last 3 months. I initially thought it was a suspension issue because of the shaking but I've surely ruled that out. Any help or input appreciated.

 

Try a cylinder balance test. Disable one cylinder at a time, and see what the engine does. Be careful just pulling plug wires though, the coils have enough juice to wack ya dead, under the right circumstances...... So, use insulated pliers, and just have the plug wire ground somewhere else while testing. (to the block would be good.)

Disable the IAC while you are testing. (Just let the engine warm fully, let it get to its stable idle speed, and then unplug it.)

See if any one, or more... cylinders have little or no effect on idle speed, those are going to be your problem children.

This procedure WILL set some codes though, you can just disconnect the battery for 10 minutes once you are done, to clear them. (be sure to plug everything back in too.)

Welcome to DF!

 

With a 17 year old truck I would check the harmonic balancer. Make sure it's not seperating, or anything. My 360 sat for awhile, and the rubber dry rotted and failed, and the whole outer ring came loose. Now if that happened to you you would notice it p, but if it's only a minor flaw it can cause this too.

 

all engine shakes i have ever seen have been due to misfires, which can or can not trip the codes. i take a glass half full of water and sit it on the motor...then unplug each cylinder one at a time until the water does not jump around like crazy and there is the culprit.

 

so how do we fix it with a fuel injector?

 

If the injector is the problem, it gets replaced. Gotta find which cylinder is the problem first.

 

Thanks for all the input/replies.. due to the lack of time (this is my work truck) I have the truck at a reputable Mechanic shop. As soon as they and I know what the issue I'll post here. Keeping my fingers crossed..

 

As of right now they are still diagnosing but said it appears a cyclinder is running lean. Fuel injector possibly?.. should have an answer today they said.

 

Let us know what ya find out.

Injector is a pretty good bet.

 

maybe a simpleton reply here, but have you checked the engine mounts? It seems that a broken one would magnify the normal vibrations.