So my mom's having some problems with her 1999 chevy blazer and the warranty's getting ready to run out (99,825 miles).

Two problems: the A/C is not cooling quite like it should, only on occasion, and there's a slight ticking noise coming from the engine when you are under easy acceleration (heavy acceleration drowns out the noise).

So I take it in to the shop this morning and await a phone call with a diagnosis of the problem. I finally received a call this afternoon telling me that the A/C checks out fine. Not a problem. They did tell me they hear the noise in the engine and it's not normal but they can't pinpoint where it's coming from or what it is. Basically, they are telling me that we can't find it so we can't fix it.

Can't find it, can't fix it. I understand that. But you're telling me you can hear a problem and know it's not normal and I have to deal with it?

Here's my beef: They know there's a slight problem now but can't pinpoint the problem. Warranty runs out in 175 miles and if something happens after that point we're SOL. So, 25-50,000 miles from now the engine dies b/c of this problem that hasn't been addressed, we have to eat it.

Anyone have any suggestions?

Already seeking a second opinion but is there anything else we can do?

That's not usually the case with warranties, in my experience. If you have reported the problem prior to the expiration of the warranty, you're covered. You need documnentation, though. This might not be the case with the A/C because they looked at it and said there was nothing wrong. Get them to say, in writing, that there is a problem with the engine, but they can't diagnose it.

Jim

The air conditioning problem might be due to a slipping belt as suggested above, or it could be a faulty AC pump clutch. These are usually electrically operated, and a bad switch, thermostat, or connector could make it cut in and out randomly. It could also be a blocked evaporator/condensor or condensor fan fault, making the system overheat and operate inefficiently. Another possibility is that the refrigerant is low or has a leak, which would make the system work more and more ineffectively until it stops completely.

The clicking noise could be a valve fault, lifters, rockers, or whatever, or valve guide wear. Does it change speed with the engine revs?

It just might be related to the AC fault, thinking about it. Possibly the pump clutch is slipping and that's where the clicking is coming from?

pca

If the A/C is cooling while the car is in motion but not while the car is idle, make sure that it is not your fan. If it is, you could end up with a cracked radiator.