Yesterday, noticed a metallic spinning noise as the truck was warming up. Got home yesterday and popped the hood to find that the pulley (upper left side of motor (driver's side)) would spin, stop, spin stop and was the source of the noise. I'm no pro mechanic, but figured this was the AC clutch. So two questions: A) can just the clutch be replaced or does it have to be the entire compressor (I'm guessing thats whats behind the clutch LOL), B) if so, how difficult is it?

Cheers,
Jeff

 

Yes the clutch can be replaced without changing the compressor. Question to you: Was the Defrost turned on? If so, the clutch cycling is normal because the A/C system is used to dehumidifier the air.

 

Ah, did not know that, but yes the defrost was on to defog the windshield yesterday as it has been rainy. So its normal for it to cycle, but is the noise indicative that the ring/bearing or something in it is wearing out and that it does need to be replaced? I have run the defrost before and this was the first time I have heard the noise.

Cheers,
Jeff

 

The noise can be caused by a compressor slowly locking up or bearing going out. Run the truck with the A/C on, listen again.

FWIW I recently purchased a 2002 Explorer from a seller that told me the A/C did not work. As it turns out the compressor was locked up. It would stall the engine at idle. In the process of figuring out the issue I ended up smoking the clutch which warped the plates. This resulted in a constant chirp with the engine running. 3 weeks and $600 later I have a new compressor, condenser, orifice tube and a working A/C system (with no chirping).

 

See, that may be an issue then. The AC was not working when I got this truck. Air blows but does not get cold. First thought was that it needs freon/R12 given its age, but as winter was here, wasn't worried about filling it just yet. And over the last couple of days, I have not heard the noise again even though the defrost has been on. The truck does stall once in awhile when I put it in park, so the compressor could be causing that also? Anyway to test to see if its locked up other than the cold air not working?

 

See if you can spin the compressor by hand. It will take some effort.

 

Copy that, will give that a try today.

 

Just tried to spin the compressor pulley. Didn't get it to move, but honestly, didn't crank down on it as its dark out already. The front of the pulley spins very freely however. Not sure if it is supposed to or not or how freely it is supposed to turn.

And saw you answered some fuel gauge questions in another thread. Fuel gauge works fine on the front tank, but only registers about half on the rear. Now when I first got the truck, it seemed to go a long time on the front tank before I switched over. Could the sender valve be the cause?

 

The front part of the pulley spins the compressor.

What kind of fuel mileage do you get when running on the front versus rear tank?

 

Well, the front plate on the pulley (not the pulley running underneath the belt), spins freely. Does that mean the clutch or the compressor are gone? I'm not sure on the mileage, I'll have to test that the next time I fill up. But given its a V8 and the tanks are only about what, 10 gallons? A tank lasted me more than a week of normal driving to and from work with just a few side trips to the store.

 

I think your clutch and compressor are fine. You can check the clutch air gap I suppose, 0.21 - 0.36 inches. Without hearing the noise I cannot give you much more than that.

In most trucks the rear tank is 19 gallons, the front is in the 16 - 19 gallon range.

 

Its just a metallic noise when the clutch kicks in. It is hard to explain.

You are most likely right, just trying to remember what I put in on the first fill up as its been a couple of weeks.