Bad vibrataions!! help me

[mustangmatt15]

hello all! i am new to this website and to the mustang scene. About a week ago i picked up my first fox body.. a 90' GT after a day of driving it around not beating on it , out of the blue a bad vibration started when the engine rpm's got up to 2500+ and got worse as the engine speed got higher. The vibration DOES still occur while the car is still in nuetral so that basically eliminated driveline problems. Today i replaced the harmonic balancer with an O.E. one and it still does it. We have came up with many conclusions such as possibly being clutch/flywheel related or internal engine related such as a bent rod of some sort or crank related. The car has a new cap, rotor, wires, and plugs. Help me PLease! -matt

If it matters engine mods are as followed- CAI, a mild cam, headers, h-pipe, flows etc...

 

[88mouse]

Welcome. Where did you get the new bal. at? The rubber in the middle of the two pieces of steel are bad about comeing out on stock bal..

 

[rockytoohot]

Could also be the fan clutch. If the fan is wobbling, it will cause the engine to vibrate.

 

[Nibbie]

Trying to find vibrations is tricky, alomost anything can vibrate, motor mounts, engine internals, harmonic balancer, drive train parts-such as clutch, flywheel or automatic parts. Bent drive shaft. Does it happen when driving or when you sitting still?

 

[fastford91]

your vibration problem could be coming fram any of the suggested spots ! another could be the motor mounts! check them out it fairly easy to do! ive had acouple friends have this problem and it was the motor mounts!

 

[mustangmatt15]

we checked out the fan and it seems to be OK... the motor mount seem pretty stiff.. It occurs while i am still with or without the clutch in as well while im driving. I think i am going to get the car in the air and take off the inspection cover off of the bell housing to see if there is any suprises in their. -matt

 

[billbraskey]

im having the same exact problem right now!! its driving me nuts.. my car starts vibrating at about 55-60 and get worse the faster i go still does it if i push the clutch in.. or am just at 1000 rpms coasting 60..so its gotta be wheels tires right? does this sound like what your car is doing? how do motor mounts make your car vibrate..?
my motor has less than 1000 miles on rebuild..gt40 irons e cam rpm intake all tires are newer have good tread.. car sat for almost 2 years recently could that have made flat spots on my tires? got the rear balanced yesterday didnt fix it..
p.s not trying to hijak your thread just didnt want to start the same exact one ..

 

[mustangmatt15]

PROBLEM SOLVED the fan clutch was toast i was just to stupid to realize it! Thanks for the suggestions -matt

 

[billbraskey]

anyone got any ideas for me? not ym fan i got electric... ot does not vibrate at all wen its not in gear and im revving it up sitting still...so its not the motor right?? still vibrates gong 60 or so with it in nuetral...

 

[mustangmatt15]

mine vibrated while i reved it neutral and while i drove... if its still vibrating while u are driving and are in nuetral it has something to do with your drivetrain such as your drive shaft, rear-end, or trans bill -matt