Vibration when travelling over 80MPH
09-30-2002, 03:24 AM
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Vibration when travelling over 80MPH
I have noticed that once the car gets to about 75-80mph a vibration sets in.
I have had the tyres balanced....it helped a little but the vibration is still there still there. I also note a little vibration when taking off which disappears once I'm travelling.
Are we talking engine mounts? The top of the intake (On 87 S4) looks high relative to cross bar, (which should suggest the mounts have not collapsed) but rev engine at idle and engine does not move ( which suggests they have collapsed!!!)
Any ideas AND are the two different types of vibration related.
Thanks.
I have had the tyres balanced....it helped a little but the vibration is still there still there. I also note a little vibration when taking off which disappears once I'm travelling.
Are we talking engine mounts? The top of the intake (On 87 S4) looks high relative to cross bar, (which should suggest the mounts have not collapsed) but rev engine at idle and engine does not move ( which suggests they have collapsed!!!)
Any ideas AND are the two different types of vibration related.
Thanks.
09-30-2002, 05:13 AM
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Burning Brakes
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Jim,
Check your toe-in of the front wheels - If this is adjusted after the car has been lifted, and the car not forced down to normal riding height, then you have no toe-in but toe-out, and when you increase the speed the wheels will starts 'bumping'
I was fighting with this problem for a long time but mine 'bumping' starts typically at 105-110 M/h
Check your toe-in of the front wheels - If this is adjusted after the car has been lifted, and the car not forced down to normal riding height, then you have no toe-in but toe-out, and when you increase the speed the wheels will starts 'bumping'
I was fighting with this problem for a long time but mine 'bumping' starts typically at 105-110 M/h
09-30-2002, 07:49 AM
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Supercharged
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Jim-
What kind of balancing are you having done? THe static machine balancing (I think that's what you call it) just spins the wheel and tire a bit to tell the tech where to put the weights. Problem- if you have a bent rim or a flat-spotted tire, or an otherwise out-of-round situation, this will not pick it up.
Solution- Find a place that uses dynamic balancing. This involves a roller that applies preasure to the tire as it spins up. This machie will then tell the tech how best to position the tire in relation to the rim and will be able to determine if you have a bent/warped rim or a bat tire.
I find the the static balancing is ususally good upto about 80-85 MPH, but if you want smoothness at high speeds, you have to go for the dynamic balancing.
If you seach the archives, you should find reference to the type of machine that does this. Hope this helps.
What kind of balancing are you having done? THe static machine balancing (I think that's what you call it) just spins the wheel and tire a bit to tell the tech where to put the weights. Problem- if you have a bent rim or a flat-spotted tire, or an otherwise out-of-round situation, this will not pick it up.
Solution- Find a place that uses dynamic balancing. This involves a roller that applies preasure to the tire as it spins up. This machie will then tell the tech how best to position the tire in relation to the rim and will be able to determine if you have a bent/warped rim or a bat tire.
I find the the static balancing is ususally good upto about 80-85 MPH, but if you want smoothness at high speeds, you have to go for the dynamic balancing.
If you seach the archives, you should find reference to the type of machine that does this. Hope this helps.
