There is a jack hammer under my hood - efans, ac, what is it?

[Dr Tahoe]

HI All,

I recently had flex-a-lite fans put in, but not sure that is the problem. 03 Tahoe with 87K on it. When I take off under light thortle, I get a jack hammer sound. When I let off the throttle, it goes away. When i hit the gas, I don't hear it. Only hapens when AC is on.

Here are my thoughts, but want to get your opion:

1) AC clutch is going out, and under low throttle, it is lock up until the belts push it hard enough. (is this it?)

2) efans somehow are getting started and electrical system makes them stall..

3) something in the engine.

I think it is #1, but am not mechanical. Reading here, it sounds like ac compressors go bad.

Let me know what additional info is needed.. gotta get this fixed... it's driving me crazay. Great truck with a horible sound.

Dr. tahoe

 

[bkboatnsleds]

Could it be the tensioner pulley... When AC is on more drag on the spring? Perhaps its bad

 

[ghost]

i had the same problem.. not so much a jack hammer sound but when a/c was on and hit throttle you could hear a lout ass noise, kind of screaching noise. it was the clutch on my compressor. grabbedt a new a/c kit off ebay and everything is all good now!

oh and my hoe has the same amount of miles on it as yours. its a pretty common problem, but the kit was 150$ off ebay for a remanufactured compressor with new accumulator and everything else. Hope this helps, good luck!

 

[TnTahoe]

definately the ac, just replaced mine, be sure to check that orifice tube for debris, i also had to replace my condenser as well