Loud Clunk when air conditioning is turned on

[RamThatStroker]

Guys,



I've been driving my dad's truck this week and I noticed it has a loud clunk when the air conditioning compressor engages. It even knocks the engine idle down when it does it. Is this normal or is their a problem... ??



Thanks ahead of time...

Joe

 

[lschultz]

Mine does it too but not every time have not noticed the idle dropping like you. The 00 I had would make the AC clunk sometimes but it seems like this 03 does it more. I have tried turning the AC off when I turn off the highway(about . 3 mile to house)and leaving the fan on to dry the evaporator out but it does not seem to make that much difference. I guess its one of those quirks

 

[smartineau]

mine did it for the first time tonight.



I have used my AC about 20 times and as I said tonight was the first. I could not get it to repeat.



steve

 

[robobx]

twice mine has made an electrical short sound not a clunk, but a zapping, sparking, electrical sound. don't know what it was, but it didn't sound good.

 

[David Muench]

Mine sometimes makes somewhat of a clunk noise when the clutch on the AC compressor engages. Doesn't sound very bad to me, my 2001 made a similar noise. It's just easier to hear over the engine now.

 

[Duck]

I took mine into the dealer for this problem, they said it was normal, but didn't have any more details to offer.



Here's a post from a little while back that is right on the money, IMO

AC Probs



Following the advice of turning off the air about 30 seconds before shutting down and not turning the air on for about 15 seconds after starting- I haven't heard the noise in quite a while.

 

[Bill Stockard]

There was another thread on this topic. Yep, our '03 does it, as did our '00 truck, and my '00 GMC Jimmy does it too. Also, I can feel the compressor vibration in the accelerator pedal at highway speeds.



The '03 Cummins engines so quiet and smooth that they create less vibration than the A/C compressor!!



Bill

 

[RamThatStroker]

Thanks guys for the help. I just wanted to make sure there was nothing wrong with dad's truck. Now if I can only convince him to BOMB it and life will be good



Joe

 

[Prairie Dog]

As we get older we have to start making decisions for our parents. Go get your dads Visa card and do whats rite for him.

 

[rbattelle]

I get the clunk too, but only when the compressor is first engaged. I attribute it to the large pressure differential that exists at the first startup.

 

[RamThatStroker]

Originally posted by Prairie Dog

As we get older we have to start making decisions for our parents. Go get your dads Visa card and do whats rite for him.

Great idea prairedog, my dad is so old school he's always preaching to me saying that if the factory would've wanted that way they would've put it that way Of course he doesn't complain when he drives my truck and it's only slightly modified. So I think I may have to take the steps for him. Now... where does he keep that credit card



joe

 

[Blakers]

Mine made the clunk today for the first time too. I've really only used the AC recently as it's been so cold all spring.



Someone said the 03s have electric clutches on the fans than come on with the AC - could the clunk be the fan clutch rather than the compressor clutch?



Does the fan clutch stay engaged all the time with the AC on? The fan sure screams! Seems like that would suck fuel.



Blake

 

[Neal Whyte]

My 98 Dodge use to make the clunk and so does my 2003 from time to time. A trick that works to stop the problem on both trucks that I have found is to turn off the a/c with the motor running for a few seconds (like 15 or 20) before you turn off the motor. The next time you turn on the a/c it don't make the noise.



I'm not an expert but I assume the compresser has pressure on it and turning it off before the motor is turned off must releave it.



Happy 4th to everyone