Vibration with A/C on
Thread Starter
Advanced
Joined: Feb 2001
Posts: 79
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From: Brisbane, Queensland,Australia
Vibration with A/C on
I am experiencing a vibration when the A/C is switched on. It actually feels like a miss, however i took it to the dyno shop who confirmed that it is not something that is happening in the engine.
Would it be the compressor or could it be any of the pulleys failing under load ??
BTW... the air actually works fine !!
Any help would be appreciated
Thanks
Steve
Would it be the compressor or could it be any of the pulleys failing under load ??
BTW... the air actually works fine !!
Any help would be appreciated
Thanks
Steve
Burning Brakes
Joined: Dec 2000
Posts: 1,161
Likes: 0
From: Orangeburg, NY
Re: Vibration with A/C on (sm90)
With the info you provided, there isn't enough to come to a complete conclusion, but I'll give it a try. First, is the unit completely filled with freon? If the unit is low, the clutch will engage/disengage making it feel like a vibration. How is the a/c clutch? Does it make nay noises when engaged? is there rattling? It may also be the a/c clutch?
Melting Slicks
Joined: Apr 2001
Posts: 2,104
Likes: 220
From: Ca.
Re: Vibration with A/C on (sm90)
And what yr is your car? On the 85-88's there is a bracket that bolts from the smog pump to the manifold-without it you'll get the vibration. To test just push hard on the smog pump bracket by hand while it's running and it should shut up if thats the problem.
Thread Starter
Advanced
Joined: Feb 2001
Posts: 79
Likes: 0
From: Brisbane, Queensland,Australia
Re: Vibration with A/C on (sm90)
Sorry guys,,
It is a 90 6sp. I don't hear any noises coming from any of the components. It is something that has recently started, therefore i don't think it is the bracket issue. With the car turned off, i can spin the inside part of the pulley. There is some resistance, but it is not free spinning. With the belt off the outside of the pulley spins freely.
Hope that helps
Thanks again
Steve
It is a 90 6sp. I don't hear any noises coming from any of the components. It is something that has recently started, therefore i don't think it is the bracket issue. With the car turned off, i can spin the inside part of the pulley. There is some resistance, but it is not free spinning. With the belt off the outside of the pulley spins freely.
Hope that helps
Thanks again
Steve
Le Mans Master
Joined: Apr 2000
Posts: 5,589
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From: DrunkDefender
CI 1-2-3-4-5-6-7-8 Veteran
CI-IV AutoX Champ
CI-IV Burnout Champ
St. Jude Donor '07-'10
Re: Vibration with A/C on (sm90)
Wonder if this is the same thing as mine? My drives fine, but has the same bad vibration but only when the a/c is on. If I turn it off then nothing? It pulls up to 5000rpm without vibration. if I turn it on then it vibrates starting at 2500rpm and gets worse as it goes up. My ac cools just fine though.
Racer
Joined: Jun 2000
Posts: 333
Likes: 0
From: Wichita KS
Re: Vibration with A/C on (red90sixspeed)
My 90 does the same thing. It starts to vibrate under acceleration about 3500. When the AC is off there is no vibration. My AC also cools just fine. I usually have the top off and don't run the AC but on those 100+ days the AC has to come on.
Instructor
Joined: Oct 2000
Posts: 206
Likes: 0
From: Nashville, Tn. 37211 TN.
Re: Vibration with A/C on (robblk90)
I don't know if all the L-98 have the brace from the a/c compressor to the exhaust manifold or not. I do know that it sounds exactly like my vibration problem until I added the missing brace. There is also another brace on the other side to th alternator. Bought the missing part from Contemporary Corvette for $10.
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Heel & Toe
Joined: Oct 2001
Posts: 15
Likes: 0
From: norcross ga
Re: Vibration with A/C on (sm90)
Could this be related to the frisbee on the waterpump pulley,that everybody talks about removing?I thought that was there to dampen vibration from the a/c.Does your car have this dampener on the pulley?
