Notices
GMT 800 & Older GM General Discussion 2006 & Older Trucks | General Discussion

Air conditioning blows warmer at idle

Thread Tools
 
Search this Thread
 
Old 07-14-2010, 08:53 PM
  #1  
TECH Veteran
Thread Starter
iTrader: (11)
 
maddboost's Avatar
 
Join Date: Jul 2002
Location: Elmhurst, IL
Posts: 4,332
Likes: 0
Received 0 Likes on 0 Posts
Default Air conditioning blows warmer at idle

I have a 2003 Silverado SS with just over 80,000 miles on it. I have owned it since it had 9,000 miles and I have always noticed that at idle or in stop and go traffic the air conditioning either blows warm air or air that just isnt as cold as when Im moving. I plan on taking it to the dealer but was wondering if anyone else has experienced this problem.
Old 07-14-2010, 09:28 PM
  #2  
TECH Addict
iTrader: (5)
 
Parke10's Avatar
 
Join Date: Nov 2007
Location: Bakersfield,Ca
Posts: 2,232
Likes: 0
Received 1 Like on 1 Post
Default

a/c pump wont be turning as hard at idle, might be why
Old 07-14-2010, 09:36 PM
  #3  
I have a gauge for that
iTrader: (42)
 
Atomic's Avatar
 
Join Date: Jan 2006
Location: Huntsville, AL
Posts: 16,252
Received 374 Likes on 255 Posts
Default

not enough airflow over the condenser so pressure builds and the compressor shuts off to keep the system from exploding
Old 07-14-2010, 09:45 PM
  #4  
TECH Resident
 
oldred95's Avatar
 
Join Date: Dec 2006
Location: Enid, OK
Posts: 870
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Atomic
not enough airflow over the condenser so pressure builds and the compressor shuts off to keep the system from exploding
The high pressure cut out switch doesn't open until like 450 psi on most systems. Its just there to keep the compressor and lines from blowing to pieces.

In most cases the high side pressure just gets higher then it should be and the system becomes very inefficient. Air conditioning is all about heat transfer.

I would say pop the plastic piece off the top of the core support that covers the radiator and condensor and look down in between the two and see how much trash is in there. Usually a garden hose is sufficient enough to wash one out or a blow gun and a good air compressor works too. My rule of thumb is if it will suck a sheet of paper against the grill and hold it then its pulling enough air across the condensor. Could be a weak fan clutch.
Old 07-14-2010, 10:07 PM
  #5  
Launching!
 
SlvySS's Avatar
 
Join Date: May 2010
Posts: 201
Likes: 0
Received 1 Like on 1 Post
Default

on my 03 ss the a/c works with out the ac button pushed, the condensore runs all the time, but if i press the a/c button i dont get any air , maybe thats your problem
Old 07-14-2010, 10:45 PM
  #6  
TECH Resident
 
oldred95's Avatar
 
Join Date: Dec 2006
Location: Enid, OK
Posts: 870
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by SlvySS
on my 03 ss the a/c works with out the ac button pushed, the condensore runs all the time, but if i press the a/c button i dont get any air , maybe thats your problem
Seems like around 2002 for whatever reason they started keeping the AC on with just the recirculate being on. My dads truck always did this. My 99 even with the recirculate only on will not turn the AC on. The AC button has got to be on before it comes on, or on defrost.
Old 07-14-2010, 11:19 PM
  #7  
9 Second Truck Club
iTrader: (11)
 
tarinitup's Avatar
 
Join Date: Sep 2005
Location: Odessa Texas
Posts: 2,442
Likes: 0
Received 1 Like on 1 Post
Default

The problem is airflow related like Atomic stated. Install some electric fans and it will help it out.
Old 07-15-2010, 12:29 AM
  #8  
TECH Fanatic
 
SILVERADO11's Avatar
 
Join Date: Sep 2009
Location: PHX AZ
Posts: 1,818
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Atomic
not enough airflow over the condenser so pressure builds and the compressor shuts off to keep the system from exploding

X2!,

could have a bad fan clutch, install some electric fans they help alot
Old 07-15-2010, 02:54 PM
  #9  
TECH Veteran
Thread Starter
iTrader: (11)
 
maddboost's Avatar
 
Join Date: Jul 2002
Location: Elmhurst, IL
Posts: 4,332
Likes: 0
Received 0 Likes on 0 Posts
Default

Ill have to check the radiator when I get home from work.

Ive always planned on installing e-fans but I want the easiest plug and play option possible.
Old 07-15-2010, 04:42 PM
  #10  
PT's Slowest Truck
iTrader: (19)
 
budhayes3's Avatar
 
Join Date: Apr 2004
Location: Hackensack, NJ
Posts: 17,863
Likes: 0
Received 2 Likes on 2 Posts
Default

Originally Posted by oldred95
The high pressure cut out switch doesn't open until like 450 psi on most systems. Its just there to keep the compressor and lines from blowing to pieces.

In most cases the high side pressure just gets higher then it should be and the system becomes very inefficient. Air conditioning is all about heat transfer.

I would say pop the plastic piece off the top of the core support that covers the radiator and condensor and look down in between the two and see how much trash is in there. Usually a garden hose is sufficient enough to wash one out or a blow gun and a good air compressor works too. My rule of thumb is if it will suck a sheet of paper against the grill and hold it then its pulling enough air across the condensor. Could be a weak fan clutch.
+1...and as mentioned above, this will cause less air flow across the condenser. I will admit though, my truck used to blow slightly warmer at idle or in traffic, but since I installed the 05 Efans it's ice cold all of the time. My 96 Blazer, which has the factory clutch fan, blows noticably warmer at idle, and it's clean between the rad and condenser, as I replaced the radiator recently and cleaned any junk out of there. Fan clutch is good too...it's just the nature of the beast in some cases.


Quick Reply: Air conditioning blows warmer at idle



All times are GMT -5. The time now is 10:39 PM.