Weird noise at startup.

[yournamehere]

While in ATL this weekend I could shut the truck off for a moment and watch the temp rise as norml due to no air or water flow. Then turn the truck back on and hear a loud, grinding/ groaning sound that quickly quits. It never does this with the A/C off, only when it's on and only when the engine temp is hot. This sound is what I heard before the old compressor went bad. Is it posiible this compressor (which is still cooling very, very well is bad as well?). I went to AutoZone and bought a fan clutch because the guy that installed the a/c was running for a long time and could be hurting my gas mileage.

Any thoughts. I know it's hard to diagnose on the computer but thoughts will be appreciated.

 

[yournamehere]

What does a smog pump sound like when it goes bad or does it just lock up?

 

[bigbrown]

mine sounded kinda like you described. there's some metal brackets that hold the fan blades in there. when i lost a blade, that bracket banged around in there. if that ends up your problem, 99 bucks at nappa auto parts for aftermarket. not a tough job, tight fit though.

i just pressed and held a screwdriver against the pump while running to find where the noise was coming from. i could feel the peices bouncing around in there through the handle.

if it is your problem...replace it asap. it can seize.