A/C Not blowing cold
 

My wife has a 2003 Chevy Tahoe with about 85,000 miles on it. The a/c does not blow cold while idling at red lights, etc. Also, it is taking a long time to cool off once she starts to roll. Any ideas so I know what to look for when I bring it to a mechanic?

My truck did that and had to replace the compressor. Check your belt to see if loose and check freon.

I would say low on freon but as previously stated it could be the compressor

Clogged orifice tube or low freon. Does condenser ever freeze up?

dink fill me in here, my ole ladys condenser froze up on the way to florida, was gonna get the orifice tube changed and re-charge the freon whats up with the condenser icing over

It could be a worn compressor clutch or freon charge.
You can get a cheap gauge at any auto parts store that is fool proof.
Just plug the quick connect to the system and it is color coded.
The colors tell you if it is low, good or too much refrigerant.
If'n I was home, I would check it for you. But I won't be home for 2 weeks.

Shaw, if the compressor and condensor start to freeze up, it may be the high pressure switch. In short, if it doesn't send signal, the compressor keeps pumping, in turn, it will make the condensor or more freeze up. It can kill a compressor in a hurry. Get it checked.

Roger that thanks man!

Check and see if you have an electric fan, for your radiator. You may have two if I am correct, one is to help pull air through the condenser for your ac, if it is not working your condenser is not efficient; especially when idling because no air is flowing through it ( ex. while at stop light) and causing high pressure on your AC system, thus poor cooling. Electric motor on fan may not be working.

Have this checked first! If you have the AC compressor changed and it still does it, now you have to fix this, double the money.

If it is not this then proceed with having AC system checked.

Hope this helps

my company vehicle is an 03 suburban and it does the same thing. Sucker won't cool off at all if its just idling. I went start it 15 minutes before leaving the other day, and the thing was just as hot as it when i first started it. It doesn't start blowing cold until I start moving. Brought it to the mechanic, he said its just old... I call BS, well either BS or my boss didn't want to pay for it to get fixed and he thought it was easier to just tell me that...

Sometimes a faulty fan clutch will cause A/C problems as well, or so I was told by a mech.

H2O is on target. 02-03 were transition years from manual to elctric fans. Some had em, others didn't. If that fan isn't pulling, it will not cool, just like your home ac.

Good call H2O

You are correct my friend. Same theory of low air flow through radiator when idling. AC condenser is right in front of radiator. Most vehicles are starting to have electic fans on them.

Also, on older vehicles the fins on the condenser will become plugged due to all the bugs it eats, they get stuck and it doesn't hurt to rinse it every couple years. That is the cheapest fix of all, but usually I am not that lucky.

Thanks, just trying to help others save some money, from my usually expensive learning lessons. :redface:

This is easy......get on the highway. If it freezes up, your low on freon. If it blows hot at a stoplight, your fan clutch is bad......at high speed, you have lots of air blowing thru, so fan doesn't matter. But usually your traveling for a long period of time so it has the time to freeze......FYI.....freon does NOT evaporate which means if its freezing up, you have a leak. I changed my evap last year, it was 800 bucks!!! Pull the dash, r&r, replace dash.....it'll never be as cold blowing as it was before......

Bad compressor clutch can slip at highway speeds also.
Mine did that when I got over 50 mph.
Worked will at idle and around town. Didn't work worth
a crap at highway speeds.

Make sure your radiator is full too. Last summer coming back from Florida we got stuck on I-10 and all of a sudden the A/C stopped blowing cold. Pulled off, filled radiator and it has t done it since. Maybe the clutch wS slipping but it hasn't happened again.

Just had my wife's 04 Yukon fixes yesterday. Hook to computer and scan it. On hers it was the temperature sensor had went out. It was telling the truck it was 50 degrees outside when it was actually 100 degrees. When u get going and the motor heat warms it up it gets hotter which makes it work. The computer will not run the ac if the temp is below 60 degrees.

ok, too much technical stuff for my dumb a$$. I am bringing it to Kwik Kar in Moss bluff at 5:15 to have them test it. Hope its just low on freon.

Ok, results from Moss Bluff Quik Kar: Freon too high: Blue guage reads 60 (tech says it should read around 30) Red guage reads 225 (tech said it should read 200). Says my orifice tube is the most likely problem. $3.00 part. $80 labor. 3 cans freon @ $20 per can. So for less than $200 I should be back in business.

Does this sound about right?

Yep!

Mais, Im smart ya me

Go back and read my first reply to your first post, the reason your pressure is high is because the condenser is not doing its job. Clean the condenser, and make sure the elecrtric fan motor is working, or the fan clutch, whichever you have.

I tried, let us know how it works out. If they open your line to change the orifice tube, please inform them to pull a full vaccum on your AC system (to remove all the Oxygen) before they charge it again with freon. If they do not, the freon mixes with the Oxygen in the line and becomes corrosive, then you will be changing the compressor and all other related AC parts.

Trust me, I hope it works for you. Just trying to help, this is not technical, just the way they make more money. Been down that road. Ask a few simple questions and help the ol' pocket book.

Its not the oxygen, its the humidity....pulling a vacuum actually boils out any water vapor that may be in the lines. Also helps to verify any leaks

tech told me that my fan is run by the belt on the engine and that it is always running when the engine is on. I will ask to have the condenser cleaned, too. I will also ask for a vaccuum on the line prior to re-charging with freon.

Btw, is there really a differnece in quality of freon i buy? He told me to get the best grade possible ( more money?) cause it will cool better than cheaper brands of freon -- true or B.S.?

Thanks for your help and input!

Fan is run by a clutch. That's why when you pull off from a light you can hear it.for a minute then it quiets down. When the clutch goes bad, fan doesn't turn the rpm it should, which means not enough air. Anytime an AC line is opened you loose all freon. A vacuum is pulled every single time that happens. Otherwise, you wont get the freon back in. So you don't have to worry about that, your mechanic is.gonna do it no matter what.

As for.the "grade" of freon???? He is blowing smoke up your a$$. Its all the same.......you want it REALLY cold?? Have him put butane in it!!! Kinda dangerous if you get in a wreck, but man, it blows ice cubes!!!!!

thanks for your help. Gonna steer away from butane. sounds great though! so, do I get the freon + oil or just regular ole R134 refrigerant? What about synthetic R134A or ULTRA Synthetic?

Oil, yes