i have a 92 GT and i was on my way home the other night and suddenly my car started shaking BADLY. the higher my r.p.m. got the rougher it would shake. so the first thing that cam to my mind was the motor mounts. i replaced those and it didnt change a thing. then i find out my harmonic balancer was goin and so i replaced that thinkin that was the problem.
so tonight after i changed the balancer i started it up and it is still shaking, not one bit of difference.
the motor is running very nice so its nothin to do with that.
the best way to describe it is as my car was a big massage chair on HIGH and gets rough the more u rev it up
any info will great.
thanks

 

Is it doing it while you are in gear driving or just sitting there at idle?

 

at idle and while i drive

 

trans flywheel. Dive shaft may me loose. Push in the clutch when it start doing it and see if it quits.

 

What have you recently taken off or worked on in your car?

 

Does it shake when sitting still or only driving....my bet the pressure plate to a dump

 

With a smooth properly running motor you can drive for a long time with a broken/worn out motor mount and never know.


Here are my guesses,..

harmonic balancer
flywheel
clutch
pressure plate

Timing chain? Possibly jumped time?

Fuel injector came unplugged, defective or clogged? Possiby an entire bank came unplugged?
Spark plug wire disconnected, or plug fouled?
Vacuum lines?

Difficult to second guess,..

but any of the above can perform what your describing.

Start with the basics and what you can visually see first. If nothing found,.. open it up.

Worst case scenario you chucked a rod cap,.. not likely but possible.

Hurst

 

well the motor itself is running great, no mis-fire or injector problems.
and i just replaced the motor mounts and harmonic balancer because thats wat i thought the problem was


and it does it sitting still when i first start it, while its idling, in 1st, in 2nd, in 3rd, in 4th ,in 5th, just all the time. it gets rougher the higher the r.p.m gets

 

Cant be running too great if its shaking like hell.

Since you have it figured out,.. I'll let you do your thing.

Hurst

 

im not sayin im doin my thing
but thanks for the info hurst