1989 Mustang Vibration Problems

strikeratt · 10-03-2009

Hey all, I'm still having problems with higher RPM vibration problems. At 3500 RPMs in any gear, including neutral, the car will violently vibrate as if misfiring. It will also only do this after it starts to get warm. So guys and gals, what would you say it is.

Any questions just ask.

mmperfdiesel · 10-03-2009

Are you getting any trouble codes? Check the O2 sensors. I found that a bad one will make it do some stuff that doesn't make sense.

strikeratt · 10-04-2009

Quote:

Originally Posted by mmperfdiesel

Are you getting any trouble codes? Check the O2 sensors. I found that a bad one will make it do some stuff that doesn't make sense.

No codes that I know of, I'll run a test tomorrow to see if they're just minor ones that won't show up for whatever reason.

O2 sensors are new, still could be a bad one though.

SM90Stanger · 10-04-2009

How are your engine mounts? I am thinking worn out mounts for some reason...

Steve

johnnshepherd · 10-04-2009

i drove my friend's 87 vert 5.0 a few days ago and it would do it above 60

strikeratt · 10-04-2009

Quote:

Originally Posted by SM90Stanger

How are your engine mounts? I am thinking worn out mounts for some reason...

Steve

Mounts are new poly mounts

Quote:

Originally Posted by johnnshepherd

i drove my friend's 87 vert 5.0 a few days ago and it would do it above 60

Wish it was a speed issue because then I could say tires or shaft and such, but I could be sitting in a driveway and bring it up to 3500 and it'll vibrate hard.

StangLX93 · 10-05-2009

i would suspect the Harmonic balancer, if it hasnt been replaced then that would be a suspect,

strikeratt · 10-05-2009

Quote:

Originally Posted by StangLX93

i would suspect the Harmonic balancer, if it hasnt been replaced then that would be a suspect,

New balancer and flywheel both balanced to 50oz

This is why I'm having a hard time figuring it out ... almost everything is new.

strikeratt · 10-07-2009

I would also like to add I'm pretty sure it's not a balance problem due to the fact it gets worse and very noticable when the car gets warm

91badazzgt · 10-09-2009

Hey buddy. My Gt did the same thing. had a 1970 302 in it. the kidthat owned the car before me had the balancer mixed with flywheel,had a .28oz balancer and a 50oz flywheel. ID definitly check the balancer. see if the rubber is torn or cracked... thats where id start

strikeratt · 10-09-2009

Quote:

Originally Posted by 91badazzgt

Hey buddy. My Gt did the same thing. had a 1970 302 in it. the kidthat owned the car before me had the balancer mixed with flywheel,had a .28oz balancer and a 50oz flywheel. ID definitly check the balancer. see if the rubber is torn or cracked... thats where id start

Nah it's not a balance issue from what I can tell since it is hardly noticable while it's still cold. Plus the flywheel and balancer are new and balanced out to 50oz

strikeratt · 10-12-2009

No one? Common guys I know there's some ppl out there that probably know