[saudekeep]

There are around 110k miles on my 1998 GT. Whenever I let off the gas pedal there is a vibration primarily felt in the floor of the vehicle and my seat. If I add gas again I can 'rev' my way out of the vibration; although it doesnt disappear altogether as soon as I add gas. It is more pronounced at highway speeds.

There is also a rotational-type vibration when I'm coming to a stop. By rotational I mean that it feels like it happens everytime something makes a complete rotation (ie. warped rotor maybe?)

I'm not sure if the two are related. :scratchchin

 

[djslimfm]

menn! careful!

start by going right away to tire shop and check for a loosen knobs

 

[djslimfm]

sorry had to many things on my hand @ that moment

you should check your tires!! for loosen knobs could be by jealousy or some stoned employee @ pep boyz lol !

if all the knots are tighten and everything looks ok by looking then check for a egged tired that could be the one giving you all this harsh driving i my self have this problem just that im to lazy to go and change it right now..! lol but in my case th eegged tire just feels above 60MPH :so

 

[racin366]

Check your tires really well, my guess is one or more of them is bad or out of balance.

 

[djslimfm]

true..... truee.......
then u can have a bud and watch the game...!!

 

[232-K7]

if it were my car i would check my tires for any flat spots and balancing, also, is the rotational vibration only felt when your braking? if so possible warped rotor, if you only feel the vibration when slowing down in gear but not nuetral, maybe a trans mount or something like that

 

[saudekeep]

Wow, lots of replies right away, thanks.

I have been experiencing this for a few months, but last month I had two new tires put on the rear. I rotated the rear tires and wheels up to the front because they still had half their life on them.

I thought that the problem might have been a bent rim or out of round tire so I paid careful attention before and after. I know that if the steering wheel vibrates the front tires/rims are bad and if the car in general vibrates the rear tires/rims are bad. Well when moving the front rims and new tires to the rear nothing changed. So I beleive this rules out the lose nuts and out of round tires/rims. Would you guys agree?

As for 232-K7's response, I'm not positive that the vibration comes about while slowing down in gear but not in neutral but I want to say that it vibrates regardless of the gear setting. I will be driving home in 1 hr and will pay special attention to this.

Again thanks

 

[DZEE]

Braking vibration is usually warped rotors.

Check your driveline and u-joints.
Get the rear on blocks, leave in nuetral, and rotate the drive shaft. Check both joint for any play. Try it in many positions. Also check for slop at the forward yoke where the shaft goes in the back of the tranny. I had a F-150 that had a vibration on decel and I had to replace the tailshaft housing to tighten things up.

While it is on blocks fire it up and let it idle in gear. Watch the driveshaft for any out-of round movement. Also a good time to watch your rims and tires for out of round or bent rims. Some tire wobble is ok since none of them are perfect. Look for an obviuos flat spot or bulge.