I got a 1990 Mustang GT with something unbalanced

[naildriverinnc]

I got a shimmy and a shake in the car it's not the harmonic balancer or the flywheel. Does anyone know how the car would act if the crackshaft was bad or could this be the cause of my shimmy and shake. The car is a 5 speed and this is what the guy done to the car before I bought it NEW 5.0L CRATE ENGINE W/ GT40 HEADS AND VALVE TRAIN
- NEW NEW WORLD T-5 TRANS AND SHORT THROW SHIFTER
- NEW 3.73 GEARS
- NEW HIGH PERFORMANCE FORD
MOTORSPORT CLUTCH
- COBRA INTAKE AND 70MM THROTTLE BODY
- COLD AIR INTAKE & UNDERDRIVE PULLEY'S

Any ideas? ..........anyone

 

[NKau]

Motor or tranny mount(s) bad or not tightened?

 

[MrStang123]

Get your tires balanced?

 

[NIKwoaC]

Driveshaft maybe. Check to make sure all bolts are in and tight. Best thing you could do right now is get under the car and look at any and all rotating pieces (drivetrain) and look for loose or missing bolts.

Edit: Does the car shake when it sits still? I should have asked this first. That would help narrow it down to the motor.

 

[NKau]

Edit: Does the car shake when it sits still? I should have asked this first. That would help narrow it down to the motor.

I read another post of his (if it's the same guy) where he stated the car does shake somewhat when in neutral, but worse with when revved. Not a whole lot of things it can be if that's the case.

To the OP, how well is it running? Does it rev cleanly and smoothly? Could be a really bad misfire?

 

[back2fox]

I went through this last year. After I changed the tranny mount, driveshaft, flywheel, harmonic balancer. I finally checked the motor mounts and one was loose.

Lesson learned. Check for loose nuts and bolts first.

 

[iwashmycar]

fan blades?.. ive done that and its not a very comforting feeling

 

[Strype]

I've had my fan blades eat into the shroud because of broken mounts before.

 

[naildriverinnc]

The car still has a vibration when sitting still and reviving it up. There is no lose of power

 

[naildriverinnc]

And I've checked the motor mounts they are fine

 

[naildriverinnc]

It idles very nice no misfires