Compressor on 77

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Jul 5, 2003 | 06:30 PM

Jerpitcher

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From: Yuma Arizona

Compressor on 77

I've got a 77 corvette, and just replaced the water pump. After putting everything back together and running the car a bit, I noticed a clicking-type noise. It only happens around 900 rpms and when the A/C is on, so I think its the front of the compressor vibrating for some reason. Does this sound logical to anyone? Could it be the tension in the belt? Thanks for your help!

Jul 6, 2003 | 08:28 AM

Bobchad

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From: Norcross GA

Re: Compressor on 77 (Jerpitcher)

I had the same problem last year and based on the reply to my post it is not an uncommon problem. The fan belt is so long that it develops some slop and hits a tab that is between the belt and the lower radiator hose. Tightening it up helps some but tooo much and you will reduce thebearing live of the compressor. I was hoping a new water pump would make the problem go away but evidently not.

Jul 6, 2003 | 08:45 AM

Jvette73

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From: Severna Park Md

Re: Compressor on 77 (Jerpitcher)

Does it click constantly or intermitantly? With the ac on its normal to hear a clicking noise as the compressor clutch cycles on and off.

Jul 6, 2003 | 11:46 AM

Jerpitcher

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From: Yuma Arizona

Re: Compressor on 77 (Jvette73)

Thanks for responding, Jvette, it happens constantly at about 900 rpms with the AC on. When I turn off the AC it stops. Its rather loud, and I was thinking it might have been the plate on the front of the compressor rattling or something of that nature. Thanks again...

Jul 6, 2003 | 11:47 AM

Jerpitcher

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From: Yuma Arizona

Re: Compressor on 77 (Bobchad)

Thanks for responding also Bobchad, Would it matter that it didn't do it before I replaced the water pump? I had to move around a lot of stuff to get the job done. I was maybe thinking the plate on the front of the compressor was rattling. Just a thought, and thanks again!

Jul 6, 2003 | 12:49 PM

Ganey

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From: CORVETTE 77 385 C.I. TEXAS

Re: Compressor on 77 (Jerpitcher)

Run it w/ the hood open, if the A/C is low on freon it will cycle the clutch on the front on & off, easily visible.

Jul 6, 2003 | 01:25 PM

Jerpitcher

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From: Yuma Arizona

Re: Compressor on 77 (Ganey)

I'll try that, thanks a lot!

Jul 6, 2003 | 02:15 PM

mrvette

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From: Orange Park Florida

Re: Compressor on 77 (Jerpitcher)

The early A6 compressors are the ling type about 16 inches front to back and about 5-6 inches in diameter.....the R4 type is about 8 inches diameter but ony about 5-6 inches deep front to back....

the A6 will very seldome cause a fan belt vibration problem, ti's a much smoother better design....

the R4 is one of those terminal GM screwups trying to save weight....they are aluminum, and pulse like crazy, causing belt loading variations meaning it slapps all over the place on the lower, return section of the belt....

try going back to your original belt, or tightening it up a bit more....if you look at it under flourescent lights you will see it vibrating aack and forth hitting that metal protector plate for the lower hose....the prescence of that plate tell me GM guys knew of the/a problem...but could not cure it.....lovely institutional screw up....

GENE