Someone recently mentioned to me that GM had a fix for a rattly AC compressor. They said it was a bracket that bolts onto something near the belt. They even gave me the part number, but I lost the pack of cigarettes I wrote it on and don't even recall who told me. Does this ring a bell with anyone?


[Modified by Martin Angus, 8:50 PM 8/5/2001]

 

Mine does this too! Lemme know when you find out!

 

Mine also makes alot of noise. Please let us know if you find anything!! :cheers:

 

Not sure about other years, but the '86 has a bracket that bolts to the back of the AC compressor and the front bolt of the exhaust manifold, which eliminates the rattle. Mine did not have the bracket when I bought it, but I saw a photo of somebodys engine here on the CVF and realized that mine was missing. I got one from Contemporary Corvette with the necessary bolts for $10. There is a similar bracket on the alternator on the other side of the engine. Hope this helps. :seeya

 

I did find that my serp. belt was operating way beyond tensioner range. Replacing the belt helped the rattle, but didn't totally solve the problem. Where can I reach Contemporary Corvette? I couldn't find a website...


[Modified by Martin Angus, 2:27 PM 8/6/2001]

 

The bracket that you're looking for is no longer available except at a boneyard. It bolts from the back of the smog air pump to the intake manifold. Mine already had the brackets from the ac to the header and from the alt. to the header and still rattled until I found the other bracket from a boneyd. I beleive it also helps stabilize the combo bracket for the smog pump and the power steering pump-mine was cracked and the lower bolt had vibrated out. Hope this helps.

 

what kind of rattle?? the compressor on mine makes a noise like a snake sound only louder when the a/c is running and it goes on and off like that every five seconds or so.I'd fix it but it ain't broke,yet. :cool:

 

I checked the entire region with a stethascope. The sound is very metallic (like a loose metal plate) and it is definately coming from within the compressor. The scope localized it to the top front quadrant of the comp.

 

Could this be a high head pressure issue?? Mine does the same thing, but I have a hose coming apart from the inside and the orifice tube is probably plugged. Just a thought.

 

Check the clutch assembly. Is there oil on the hood above the compressor? Have someone operate the a/c while you observe the clutch, especially after the car has sat for awhile. Does the assembly appear to be slipping when the a/c is initially engaged? You can also remove the pressure plate and see if it or the rotor (pulley) is badly scored. It's held on with a 10mm bolt and though there is a special tool to hold it with you can us oil filter pliers (wrap the jaws with a shop towel) just as effectively. If the surfaces are badly scored, your noise may be cured by replacing the pressure plate and rotor or you can buy the whole assembly which would include the coil, though that part rarely goes bad or is the reason for the noise. Hope this helps.

 

Push hard in a couple diff. directions on the smog pump and the bracket that goes from the smog pump to the alt. If the rattle starts to shut up then you need the bracket. I thought it was my ac pump too-replaced it and it still rattled.....then I figured it out!

 

I have put pressure on the belt components and was able to eliminate the noise. I also changed the ac compressor twice with new ones to no improvement in the rattle sound...no doubt I need the bracket. The question is...where do I get it?

 

It looks like its the clutch making all that noise on mine. The thing is practically brand new and so is the compressor. What gives? :confused:

 

RE clutch going bad. Was the compressor new or rebuilt? What sometimes happens is the stationary shaft on the front housing (which the pulley fits over) gets out of round or chewed up when the bearing fails or just from sloppy installation and removal. Also, check the clearance between the pressure plate and the pulley. On mine (an '89) the specs are .02 +/- .006.

 

My rattle has been eliminated !!!!

I own a 1987 and am experiencing this same annoying rattle only with the A/C on. I thought the problem was due to a worn belt tensioner since the sound goes away when I apply pressure to the tentioner with a wrench. I replaced the tentioner and the problem still exists. I had also recently replaced the drive belt . The noise is definitely not coming from the A/C compressor but from the area around the tensioner. I checked the mounts on both the power steering unit and the A/C unit and everything is tight and vibration free. On a hunch, I checked with my parts supplier on the belt which had been recently installed to determine if this is the correct belt. The belt was manufactured by Gates and is part number K060888. According to Gates, this is the correct belt for a 1985-1987 Corvette. I then checked with Dayco and the corresponding belt manufactured by Dayco is part number 5060885. The interesting difference between the belts is that the Dayco belt is slightly shorter in length than the Gates belt. I was going to install the slightly shorter Dayco belt but it was not available, so I purchased the next size smaller Gates belt which is part number K060882 and the dimensions are 21mm wide by 2255mm in length. This belt is listed as the correct belt for a 1984 Corvette. I installed the new shorter Gates belt with no difficulty and the problem was resolved. My sense is that the shorter belt changes the position of the tensioner and this prevents the tensioner from bottoming out at the end of its travel. The rattling noise is "apparently" caused when the tensioner approaches the end limit of its travel and rattles against the housing to which the pulley is attached. This belt change may not address all the problems listing in entry, but it definitely corrected my very annoying rattling problem. For the price of a new (shorter) belt it's definitely worth a try. :D