vibration during acceleration
Thread Starter
Drifting
Joined: Jan 2010
Posts: 1,624
Likes: 48
From: Saudi Arabia
Took the car to a electrician , he said the ac clutch is fine.
He told me the problem might be because of the tensioner. !!
if there is a problem with the tensioner , it should be there while the ac is off ?? why it only happens when ac is on !!!!
He told me the problem might be because of the tensioner. !!
if there is a problem with the tensioner , it should be there while the ac is off ?? why it only happens when ac is on !!!!
Burning Brakes
Joined: Jun 2003
Posts: 1,079
Likes: 1
From: Niagara Falls ON
Check "all" of the bolts at the ac compressor. Make sure that they are all tight. Check the belt tensioner to make sure it is tight.
Also, why an electrician for an ac clutch? It engages with electricity but its function is physical. If the clutch has physical problems it will engage but could slip and cause vibrations. Check again.
Also, why an electrician for an ac clutch? It engages with electricity but its function is physical. If the clutch has physical problems it will engage but could slip and cause vibrations. Check again.
Thread Starter
Drifting
Joined: Jan 2010
Posts: 1,624
Likes: 48
From: Saudi Arabia
Check "all" of the bolts at the ac compressor. Make sure that they are all tight. Check the belt tensioner to make sure it is tight.
Also, why an electrician for an ac clutch? It engages with electricity but its function is physical. If the clutch has physical problems it will engage but could slip and cause vibrations. Check again.
Also, why an electrician for an ac clutch? It engages with electricity but its function is physical. If the clutch has physical problems it will engage but could slip and cause vibrations. Check again.
Do I need to remove the belt to check the tensioner tightness ?
The air is cool inside the car , clutch engages , the guy told me if the clutch is bad the air won't be cool !!
I'm not sure how can I know if the ac clutch is slipping !!
should I replace it ?
Instructor
Joined: Jul 2011
Posts: 166
Likes: 0
From: Chardon Ohio
Honestly I hardly ever run A/c anyway and it's done it ever since I bought the car. Also when I first bought the car the system was completely discharged and had to be charged several times before the seals would keep the refrigerant in and I thought the vibration was a dying compressor due to the lack of lubrication for however long it went without refrigerant.
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Thread Starter
Drifting
Joined: Jan 2010
Posts: 1,624
Likes: 48
From: Saudi Arabia
Honestly I hardly ever run A/c anyway and it's done it ever since I bought the car. Also when I first bought the car the system was completely discharged and had to be charged several times before the seals would keep the refrigerant in and I thought the vibration was a dying compressor due to the lack of lubrication for however long it went without refrigerant.
I can't drive without AC on and full ac , today's temp was 113F
actually I barely drive the car in the summer , I live in a hot humid area. Which sucks this time of year , and thats why I'm preparing for some online orders.
I need to check that.
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
Tensioners DO wear out but its a slowly increasing squeek or chirping vs a rattle or banging noise. More like what a belt would sound like...
IF you rev the motor and can SEE the tensioner vibrate ANY with or without the a/c on...replace it. A good tensioner will NOT vibrate or even jiggle as rpm goes up and down...it should smoothly move a little bit to compensate for the added drag on the belt.
A REAL tensioner can cost $150 locally...cheapo remans $90 or so.
You get exactly what you pay for in this dept.
IF you rev the motor and can SEE the tensioner vibrate ANY with or without the a/c on...replace it. A good tensioner will NOT vibrate or even jiggle as rpm goes up and down...it should smoothly move a little bit to compensate for the added drag on the belt.
A REAL tensioner can cost $150 locally...cheapo remans $90 or so.
You get exactly what you pay for in this dept.
Instructor
Joined: Jul 2011
Posts: 166
Likes: 0
From: Chardon Ohio
Burning Brakes
Joined: Apr 2011
Posts: 917
Likes: 25
From: College Station Tx
I am having the same issue. I've tried revving the engine in the driveway with the clutch engaged, no vibration. It only vibrates when moving down the road and the clutch engaged.
I read on an older post here that the vibration can be the result of a missing bracket that goes from the back of the compressor to the header. This bracket is oftentimes removed and left off if headers are installed. The PO had shorty headers installed and this bracket is missing. The header install was really crappy so I went back with stock. Now I am looking for the bracket.
I read on an older post here that the vibration can be the result of a missing bracket that goes from the back of the compressor to the header. This bracket is oftentimes removed and left off if headers are installed. The PO had shorty headers installed and this bracket is missing. The header install was really crappy so I went back with stock. Now I am looking for the bracket.
Thread Starter
Drifting
Joined: Jan 2010
Posts: 1,624
Likes: 48
From: Saudi Arabia
It works but I don't want to drive the car with vibration that leads to something more serious.
I am having the same issue. I've tried revving the engine in the driveway with the clutch engaged, no vibration. It only vibrates when moving down the road and the clutch engaged.
I read on an older post here that the vibration can be the result of a missing bracket that goes from the back of the compressor to the header. This bracket is oftentimes removed and left off if headers are installed. The PO had shorty headers installed and this bracket is missing. The header install was really crappy so I went back with stock. Now I am looking for the bracket.
I read on an older post here that the vibration can be the result of a missing bracket that goes from the back of the compressor to the header. This bracket is oftentimes removed and left off if headers are installed. The PO had shorty headers installed and this bracket is missing. The header install was really crappy so I went back with stock. Now I am looking for the bracket.
It can't be because of the bracket.
Nothing changed in my car , the problem suddenly came up.
maybe one of two :
1- AC clutch
2- Tensioner
I'll check the tensioner when I go home.
Thread Starter
Drifting
Joined: Jan 2010
Posts: 1,624
Likes: 48
From: Saudi Arabia
Did you remove the A/C braces when installing headers?
No , just wasted time and money. Still in the progress of troubleshooting the cause of this.
I changed the tensioner pulley and still the same. Will be changing the AC compressor clutch and see if it works
Last edited by Mohammed_z; Jul 13, 2012 at 03:16 AM.
Advanced
Joined: Jun 2012
Posts: 89
Likes: 3
From: Zimmerman MN
Mine does this too. Only with A/C on and at about 2300 rpm. It does it while accelerating or decelerating and always at 2300 rpm. Weird. It vibrates the whole car all the way back to the tail pipes. I thought it might have been a u-joint at first, but it does it at a complete stop too.
I also have headers, that seems to be something we all have in common with this problem...no?
I have not checked to see if that compressor bracket is on mine or not.
I also have headers, that seems to be something we all have in common with this problem...no?
I have not checked to see if that compressor bracket is on mine or not.
Thread Starter
Drifting
Joined: Jan 2010
Posts: 1,624
Likes: 48
From: Saudi Arabia
Mine does this too. Only with A/C on and at about 2300 rpm. It does it while accelerating or decelerating and always at 2300 rpm. Weird. It vibrates the whole car all the way back to the tail pipes. I thought it might have been a u-joint at first, but it does it at a complete stop too.
I also have headers, that seems to be something we all have in common with this problem...no?
I have not checked to see if that compressor bracket is on mine or not.
I also have headers, that seems to be something we all have in common with this problem...no?
I have not checked to see if that compressor bracket is on mine or not.
Let me know when you find the problem , the vibration sucks and the weather is hot here.
Also take some pics of the bracket.
Burning Brakes
Joined: Apr 2011
Posts: 917
Likes: 25
From: College Station Tx
The FSM shows a brace that appears to go from the back of the compressor bracket and bolts on to the header. I don't have this brace on my car. I've looked at a number of LT-1 pics here and I don't see it on any of them either.
Race Director
Joined: Jan 2002
Posts: 12,263
Likes: 86
From: O'Fallon Missouri
Edit: Both a/c braces can be used. It was the alternator brace I had to eliminate with the header install. See next post for updated pic.
Last edited by STL94LT1; Jul 15, 2012 at 11:29 PM.