Air Conditioning CRUNCH at startup

[grabinov]

I have an 04. 0 Laramie (if this makes any difference to this problem). When the truck is not warmed up - like when just started it in the driveway - and I turn on the A/C, I get a CRUNCH as the compressor starts to spin. It's bad - it sounds like a bunch of sticks caught in the belt running through a pulley or something. I checked, no sticks, no visible belt or pulley problem.



The noise does not happen when the truck is warm (or maybe I don't hear it when the engine is under load / truck is moving), and there is no noise and no problem when the engine is running with the A/C on. The noise only occurs when the A/C is started.



Has anyone had this problem? I couldn't find any posts on it...

 

[Matt400]

Originally posted by grabinov

Has anyone had this problem? I couldn't find any posts on it...

Mine has done that, very rare and extremely intermittent but has happened a few times. Loud enough that anyone else on board says... what the heck was that!?

No way to track it down being so intermittent for me.

 

[klenger]

Mine's done it too. I ignore it.

 

[sag2]

Mine has done it since the weather has started to warm up (February for us) and it does it mostly after a cold start, but will do it when warm if it sits for a while. It sounds like there might be a bit of oil slugged in the compressor, and it has to pump it out as the clutch engages.

Mini van had it and they come out with a software flash to start the compressor while cranking so you would not hear the clutch make the noise. Also with a little V-6 it made more of a noise than our Cummins does.

Drive it and enjoy that cold air. The third gens have one of the best performing A/C's I've seen.

 

[roperteacher]

Mine makes a "Clunk" everytime I turn on the A/C especially when cold. It's more of an instant "Thud" than sticks running thru. But every single one of my trucks has done it so I don't worry...

 

[XJSuperman]

same here... rare but it does happen.

 

[DPKetchum]

When buying mine and on the lot it did that. Started several others and they all did also. warm weather or used daily it dosen't.

 

[JoelCool]

Mine did it once. I didn't like it. We'll see how it goes through the Summer months.

 

[lil red cummins]

most of my vehicles have done this when you first turn on the compressor after not being used for a while. i believe it is a rust build up on the clutch faces. because the mating surfaces are not perfectly clean, they "slip" momentarily till the rust (or dirt) is wiped off.



thats the closest i have come to diagnosing this phenomenon.



jim

 

[inarush76]

Mine makes the noise as well, also mine and several others I have spoken to have had freeze up problems. A/C almost quits blowing (blower running) and will see ice build up on lines near firewall. Shut off a/c for a little while and all is well again. Most prevalent during rainy weather or high humidity. My 98 has never done this in similar conditions. Evaporator case drain problem?



James

 

[Tony T.]

AC sounding off at times.

Mine has also done the thud sound from the ac being turned on. First time I heard it I thought that a cat had got in engine compartment an lost one of his nine lives.

 

[sfr1047]

Here in Arizona I use mine every day and every day the A/C clunks hard when I turn it on. So much for the not being used for a while theory.

 

[grabinov]

Thank you all, At least it's good to now I'm not the only one. I have a lot of warranty left, so if it (the A/C clutch) is going to fail, it'll probably be covered...