LAWTON54

On an 81, is it normal for the compressor to vibrate during operation?
I have replaced the compressor 2x and still no luck. Any ideas?


[Modified by LAWTON54, 8:41 PM 8/10/2003]

LAWTON54

TTT

LAWTON54

TTT

Desertdawg

What kind of vibration are you getting? is it just vibrating in the mount a little? or is it shacking the whole engine bay?

I think they all wiggle a little, but that could also depend on where you are getting you compressors from, NAPA and places like that are a :nono: in my book.

LAWTON54

It vibrates in the mount at idle. It seems to put too much of a load on the engine. I also own a 68 and I do not notice any vibration or extraordinary load when I turn the air on. They are different types of compressors, but I dont think that the vibration and load the I am experiencing on the 81 are normal.

Bobchad

I posted the same problem on my 77 and came to the conclusion that this is one of the idiosyncracies with the car. Just off idle the drag on the compressor and the long run of the belt causes a vibration that shows up with the belt hitting a tab on the underside of the bottom belt run causing a light ringing bell sound. Evidently the General put this tab here because they knew of the potential problem and was trying to protect the lower radiator hose underneath it. Several others posted that they were having the same problem.

Crash80

My 80 does a kind of oscillating vibration at idle as well. This only started after I had some engine work done. I can up the RPMs ever so slightly and it goes away. Here is where I have concluded my problem is coming from. There is a bracket that attaches from the manifold, under the carb that goes to more compressor bracketing. It is held there with a bolt. That bolt has always been missing on my totally stock Vette. After my last round of work done on the car, the mechanic replaced this bolt. (This mechanic is awesome, how many do you know who would put a bolt back that was not originally there when they started work on it?) I have lessened the effect of the vibration by taking the bolt out and putting a rubber washer on the compressor end of the bracket and re-installing the bolt. Everytime I take the bolt out, the vibration goes away. Check and see if this might be your issue as well. The first time I heard it, it sounded like something bad was about to happen, like big parts were getting ready to start to fly around under the hood.

Best of luck!
CVT4ME :cheers:

Master Ho

I wonder if the original bolt vibrated out of the hole or if someone removed it somewhere along the way...

Crash80

who knows? I think someone probably removed it to rid of the vibration. Once it is in place, it is pretty tight and secure. The compressor is fine without it. It does not wobble or shift about at all.

CVT4ME

LAWTON54

Thanks for your idea, I am going to try taking the bolt out first and then I will try the rubber washers and see if the vabration and noise go away in either case. Thanks to all that answer my post.


[Modified by LAWTON54, 4:34 PM 8/11/2003]

LAWTON54

Thanks for your idea, I am going to try taking the bolt out first and then I will try the rubber washers and see if the vabration and noise go away in either case.