Air Conditioner problem???

[mconstable]

Did a search and couldn't find anything, but when I first kick on the A/C it engages with a pretty loud crunch... sure doesn't sound normal, anyone else having this problem? thanks in advance!!!

 

[AggieJustin]

Is it doing it all the time, or just after the truck has been parked for a while?



Even though mine's not a 3rd gen, I notice it on mine after my truck has been parked at the airport for 5 days. When the compressor first kicks in, it makes a loud crunch/pop. Just started doing it over the last few weeks.



JM

 

[ThomasWhite]

about three weeks ago I posted a topic dealing with this problem my 03 was having the same problem you just described. I took it to the dealer and they ended up putting a new compressor in, I took it on a two week trip pulling a heavy 5er with no problems, yesterday I jumped in for a quick trip down the street and "bam" there the same noise again so I guess its back to the dealer...

 

[Bill Stockard]

After setting overnight the A/C compressor on my '03 3500 engages with a clunk. My '00 3500 did it and even my '00 GMC Jimmy does it too. I think it has something to do with the oil collecting in the compressor overnight and/or the refrigerant pressure being equalized on low and high sides of the system.



Bill

 

[mconstable]

I do think it's on the first start-up of the day... thanks for the info!!

 

[Fitter48093]

Here's my idea, After running the compressor and shutting down the refrigerant is in a gas state. When it starts to cool it will condense. Rule of physics says refrigerant likes things cool. So if the outdoor are temp is less than the cab temp, it's possible the gas will collect in the under hood area. Now the accumulator will take some of this up and " store" it , But what's in the compressor stays and turns to liquid. When you start the air what your hearing is the slug of liquid the compressor is trying to pump. Try bringing engine up to temp before starting air, this will help boil some of the liquid out of the compressor. And leave nothing but vapor. it's also helpful to shut the air off before stopping engine.

 

[GLolas]

Question..... on 2003, how often should the compressor be cycling on and off. Mine seems to do it quite often. In some cases like three or so seconds. It still blows cold and there don't seem to be any problems but I noticed that it was doing this while idling in front of the house the other day.

 

[Prairie Dog]

Mine does that too, only runs maybe 5 seconds but I haven't had it in any really hot weather. Maybe it will stay on longer in high humidity and heat?

 

[M36]

I have the same clunk. I also noticed, and does anyone else have a peculiar odor when turning off the AC and using just the vent? I get a terrible odor, that eventually goes away.



Jim

 

[Prairie Dog]

Originally posted by M36

I have the same clunk. I also noticed, and does anyone else have a peculiar odor when turning off the AC and using just the vent? I get a terrible odor, that eventually goes away.



Jim

Jim, Are you sure it's not just your diet?

But really its normal and can be minimized by turning off the a/c and running the vent on high for a couple of minutes before you stop the truck.



Also, I think the short cycling of the compressor may be normal. I had a repair done to my heater box and they had to evacuate and recharge my a/c. It worked the exact same way before and after the repair.

 

[Duck]

Originally posted by Prairie Dog

Jim, Are you sure it's not just your diet?

But really its normal and can be minimized by turning off the a/c and running the vent on high for a couple of minutes before you stop the truck.



Also, I think the short cycling of the compressor may be normal. I had a repair done to my heater box and they had to evacuate and recharge my a/c. It worked the exact same way before and after the repair.

PD - I've been trying this for a few days now and so far the noise has disappeared.

I think you hit the nail on the head about the gas/liquid state.

 

[rustyrod]

AC Big Stink and Clunk

Prairie Dog and I have the same headache causing, down right nasty smelling AC Blues!



My dealer tried to tell me it was the AC recirculating the leather seat smell. . What more could I ask. He is the same guy that thinks he fixed my drive-train clunk by saying "they all do that"!



I have found that you can make it stink if you come to a quick stop and then accelerate rapidly. At about 50 mph, the rot comes reeking out of the vents like the exhaust of a moldy vacuum cleaner with something dead inside. It gives me an instant headache. I seldom get headaches and this smell can bring one on in a heartbeat. I wonder what chemical soup I'm breathing?



I am bringing my truck in and will go through the stop start sequence with my service mgr. I will let you know what he finds and please do the same for me

 

[Midnight]

The refigerant is in a gas state when coming out of the compressor to the condensor. From the condesor to the evaporator where it has dropped in pressure to a gas state and then back to the compressor to start the process all over again. Praire Dog is correct, you should turn the a/c off and just leave the fan on high to help dry up any condensation to eliminate the stink. The dealer can spray the face of the evaporator with a chemical to get rid of the stink. I have heard of and seen where rodents some how find their way into the duct and find a nice place to s~it. That stinks.

 

[Prairie Dog]

Re: AC Big Stink and Clunk

Originally posted by rustyrod

Prairie Dog and I have the same headache causing, down right nasty smelling AC Blues!



My dealer tried to tell me it was the AC recirculating the leather seat smell. . What more could I ask. He is the same guy that thinks he fixed my drive-train clunk by saying "they all do that"!

But, but, but, I don't even have leather seats.

Is there anyplace I can buy this condenser B. O. stuff?

 

[MMeier]

A/C deodorant

If your D/C dealer won't sell you the stuff go by your local DORF dealer. You usually spray the stuff into the ducts till it comes flowing out all over the place then let it sit for a bit, then fire up the system again, oh by the way if you do go to DORF be sure to park directly in front of the showroom, sales guys love itwhen all their prospects run over to see the competition!!:-laf :-laf

 

[Kilby]

Re: A/C deodorant

Just go to a NAPA store and tell them you want the AC deoderizer stuff in a spray can. I just bought this stuff last week for my old Dodge. I think it ran $11. 00 for the can.

 

[Boonieman]

The A/C compressor will cycle like that if there is very little load on it. For example, the cab has cooled way down, or you have the fan on low, especially in recirc mode. In warmer weather, or the fan on high it won't cycle nearly as often. It's the low pressure cutout on the suction of the compressor causing the cycling. It will also cycle like that if your low on refrigerant, but you won't have nice cool air either. The compressor will also cycle like that if it has high discharge pressure... . which normally means you have a leak in the system and got air in your system, or the condenser is dirty, or a combination of a dirty condenser and really hot outside air. And just a note on the stinky smell, if you run your A/C on recirc mode alot, you don't pull in any fresh air and it will cause the vent system to stink up really quick. I very, very seldon use recirc mode at all. I always keep a window slightly crack to keep the cab purged and constantly bringing it fresh air. Mine has no smell.

 

[azpete]

Just another question about the ac clunk. I have an 01 and it just started doing it this summer. After starting the truck in the morning and let it run for a min or two when I turn the air on , not only the clunk but the engine stumbles for a fraction of a sec like it was going to die. Is that what everyone else is experiencing? Am not sure but to think that when I have the DD Comp off it doesn't do it. Will have to experiment with that.

 

[Prairie Dog]

Re: A/C deodorant

Originally posted by MMeier

... if you do go to DORF be sure to park directly in front of the showroom, sales guys love itwhen all their prospects run over to see the competition!!:-laf :-laf

MMeier, You've got a very tasteful mean streak. I'm glad your on my side.

 

[Eric_77]

Two things run your truck on vent for about the last 2-3 minutes of each trip to defrost the evaporator and second don't use recircultae for extended times as you draw in body odor that then causes bacteria to grow on evaporator surface.