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Funny noise

What is the embarrassing clickety sound my 2001 Tahoe makes when I accelerate with the AC on?

We can’t tell from here.

How many miles are on it?
Where does the sound seem to be eminating from?
does it only occur with the AC on?
Are there any other thing sthat affect it?

If it only happens with the AC on, it could be either a failing compressor (or clutch), or even a component of the AC system such as a charging valve or expansion valve.

80,000 miles for a 2001 Tahoe.

Sound comes from the engine compartment and I would compare it to putting a playing card on the spokes of your bicycle. Of course much louder. And ONLY when the A/C is on.

And only when I accelerate from a complete stop.

Or…running a stick along a picket fence.

Have you opened the hood and tried to ascertain its origin?

My guess is something touching a fan.

Does it make the noise while the car is sitting still and you’re revving the engine?
Does your radio go up to 11?

How old is the serpentine belt? The belt on my 2000 Blazer gets noisy after 3-4 years. The Goodyear Poly-V belt seems to be the quietest of the belts I’ve used. Use a spray bottle to wet the belt with the AC running to see if the noise goes away.

Ed B.

Joseph makes an interesting point. Many vehicles now have two seperate cooling fans, one activated by an engine temp sensor and the other activated whenever the AC is engaged. His guess that it might be the AC activated cooling fan is an excellent thought.

Now go open the hood…