I am on the road with my 97 F250 PSD and the truck has developed an intermittent but SEVERE shaking. I really need some help here. By the way, can anyone recommend a good mechanic in Albuquerque?

The symptoms:

• Severe shaking which is intermittent.
• A low grade (barely perceptible but not normal) shake at idle
• More prominent going up hills
• The shake has a wobbly feel to it.
• Pushing in the clutch (going down highway) results in an immediate but short lived worsening of the shake which diminishes with lowering RPMs.
  • If you then (clutch still down) push down on the accelerator the shaking returns.
• Once the shaking starts it the truck has to be turned off and set for a min or two to prevent the shakes from resuming at start up.

Things that can be eliminated:

• Front hubs rotors and Ball joints & tires- new since the problem started
• U joints- checked
• tie rods- checked

Other information:

• Clutch is two going on three years old but seems to operate fine (does this argue for a bad fly wheel?) Onset of the severe shakes is NOT caused by use of the clutch.
• I feel like there has been some loss of power over the last month or two but nothing I can quantify.

Thanks in advance, I am really in a pickle here folks....

 

If the clutch is a Dual Mass type then that would be the culprit IMO.

It may be the engine, check the wire harnesses going to the valve cover gaskets, they contain the wiring for the glow plugs and injectors. Unplug them, inspect for burnt or loose pins/sockets in the connectors.

 

A couple tanks before this started I used some diesel fuel treatment I picked up at a Flying Js. Is it possible that the fuel treatment did something funky?

 

Your symptoms scream bad Dual Mass flywheel!!!

That would be my bet!

 

Sounds like a burned under valve cover harness to me.

 

Is that a major fix?

 

Is that the same harness that handles the glow plugs? A couple years ago I had to have those worked on, same time I had the present clutch installed as a matter of fact.

 

That would be them not to bad to fix just pull air intake an vavle covers

 

Is the test for this a computer diagnostic or do the valve covers have to be pulled?

 

Oh, and thanks everyone who has weighed in- its a big help!

 

Sorry but the VC has to come off

 

Not a hard fix on the VC's.
The flywheel is what it sounds like to me. I had identical symptoms and it was the DMF flywheel.

 

Me to. My DMF failed almost right after my II's were put in.

 

Got into the shop this AM, this is what they found, a whole bunch of missing ball bearings. Additionally, they are telling me there is an issue with the 'rag joint' in the steering. I guess I will be reading up on that tonight.

 

It was the "lack of power "comment that threw me...