Poor / No AC at idle

[tahoe4hogs]

I just bought a 2004 tahoe 4.8. The AC does not cool at all when it gets 90+ and I'm am not moving. It works fine the rest of the time. I'm thinking low 134 or the fan is just not getting enough air through the grille. Any thoughts?

brad

 

[Dynamo]

Sounds like your fan clutch may be bad. If it is not engaging then it would barely (if at all) draw in air through the condenser coil when you are not moving which would make your a/c not work well.

Shut the engine off after it has been idling a bit and the engine bay is plenty hot then see if you can move the fan by hand. It should be relatively stiff and not spin very much. If it spins freely then it needs to be replaced.

 

[WickedGoat]

Check the fan as Dynamo suggested. If that is good, make sure you have enough coolant. Being that you have an '04, you may want to consider changing it since Dexcool is only good for 5 years or 150K miles. The reason I suggest this is because your cooling system needs to be up to ***** for your A/C to be at its best. You can also see if the A/C compressor clutch is cycling as it should be. Last thing to do is get the A/C system checked for leaks and have the system recharged.

 

[tahoe4hogs]

Thanks for the replies.

I checked the fan with it warm and I can spin it easily by hand but it will not spin freely. The AC was working pretty well at the time and its about 100 today. I will have to wait till it acts up and check it again. I'll check the coolant and compresser also.

brad

 

[scott99zx6r]

Sounds like an air flow problem. Def. check the fan clutch. When its warm it should engage (hard to turn). If its easy when warm its ****.

 

[OKLAGMCRUISER]

instead of replacing the fan clutch with a stock fan clutch upgrade to e-fans!

 

[tahoe4hogs]

I replaced the fan clutch now just waiting for a hot day to see if it fixed the problem. It's normally close to 100 this time off year but we just set a record for rain it july!

 

[JennaBear]

Do you have any aftermarket stereo equipment? If you put an overdrive pulley on there, you should see an increase in idle amperage and better AC. Efans would be a huge plus too.

 

[Rivieraracing]

I replaced the fan clutch now just waiting for a hot day to see if it fixed the problem. It's normally close to 100 this time off year but we just set a record for rain it july!

How much did you get your clutch fan for and is it OEM, I did the test as described in this thread and with the engine compartment hot it turned pretty easily with the truck off, I'm going to let it cool down and try that and see if it is the same!