All;

The A/C compressor makes some pretty terrible noises at idle, which goes away at higher RPM. I've only had the car a little while, the previous owner actually went to the trouble to buy a NEW OEM compressor, hoping to stop the issue..it's obvious the compressor IS new, perhaps less than a year old, but he said replacing the compressor didn't change the nature of the problem.

It's an L98, with the V-belt setup, and I think I've discovered the problem.

There's a round brace that bolts to the top corner of the top bracket, and then mounts to a stud below and behind the compressor, somewhere around the exhaust manifold....mine's missing, which I suspect was his problem all along.

However, looking closely, it appears the exhaust manifolds on my car are not the original L98 manifolds. The casting number indicates they were used on mid 70's V8's. They're the 'ram' style, with a bar running across the top of them, tying the runners together.

Having not actually seen the missing bar in question, this makes me wonder...WHERE does the bottom of this bracket mount, and does the fact my car has the incorrect exhaust manifolds prevent me from mounting this brace, if I should find one?

Secondly, anyone know if any other cars use the same brace, other than TPI F-bodies?

The exploded drawing I found on thirdgen.org shows the P/N as 14082307 for the brace. Not surprisingly, GM discontinued it a long time ago.

 

Factory tpi has that brace bolted down to an exh manifold bolt/stud that is about 3/4" long past the bolt head. Then a but holds the brace to it. Think it's the 3rd from the frt exh bolt goes to that's how my serpentine one is.

 

The brace looks to go to exhaust bolt #3... in front of port #3.




The final pics gratuitous bracket setup shots. I think the tall valve cover bolt is in the way of the braces, and the header does not have an extended boss to support the bracket.

From another TGO thread...
https://www.thirdgen.org/forums/atta...0110206_4a.jpg

 

Any idea where to find the support bracket/Rod? They are long discontinued by GM...seems to me that the best bet would be to find someone with a TPI car that swapped to a serpentine setup, and still has the original brackets.

 

GM came out with a TSB for noisy compressors that added the brace in the photo for v-belt equipped cars.



I'd try to find and add this brace the existing brace that runs from the top of the bracket to the 3rd exhaust manifold stud.

 

Actually, neither of those brackets are on my car, which is most likely the source of the noise . I haven't been successful yet in finding them anywhere.

 

Thanks so much for posting this.