A/C is not cold anymore....

[TCHRISD]

I have a 02 3.4L auto trans impala.
the a/c has stop getting cold. last summer it ran fine. Air blows and will get hot but won't get cold.

Can yall fine peeps give me some pointers of things that may contribute to this before I have to bring it to a mechanic.

thanks

[jerryg2112]

Might just be low on refrigerant. You could try topping it off with some R134. Buy the big can with the gauge and follow the directions. I just did my 99 Lincoln last summer and the AC is as good as new.

[TCHRISD]

Originally Posted by jerryg2112

Might just be low on refrigerant. You could try topping it off with some R134. Buy the big can with the gauge and follow the directions. I just did my 99 Lincoln last summer and the AC is as good as new.

Well it took me a while to test it cuz Houston cold season lasted WAY longer than normal..... probably like the rest of the country.
I did what you said. The gauge read a little low on freon , so I just topped it off.
Still nothing. Blowing room temperature. I look under the hood. Fan seems to blow when A/C on. Pulley spinning on the compressor. I check the fuses and they seem to be good. Anything else to look for besides starting to check prices on another compressor?

I appreciate the help

[j cAT]

Originally Posted by TCHRISD

Well it took me a while to test it cuz Houston cold season lasted WAY longer than normal..... probably like the rest of the country.
I did what you said. The gauge read a little low on freon , so I just topped it off.
Still nothing. Blowing room temperature. I look under the hood. Fan seems to blow when A/C on. Pulley spinning on the compressor. I check the fuses and they seem to be good. Anything else to look for besides starting to check prices on another compressor?

I appreciate the help

with the ac on compressor pulley clutch engaged ,blower fan to high,, feel the condenser piping if it is warm and not hot then the compressor valves are shot just make sure the compressor is rotating ...then also check the piping at the evap unit near the fire wall is that piping cold. if not then you will need this checked out..

if you hooked up gauges to it hi and low side then we could do more on the troubleshooting the problem.

if the compressor does not create pressure then you will get no cooling. 80 deg f air temp R134 pressures will be approx.. 45 psi lo side 300 psi high side..

[TCHRISD]

well I let it run a bit and it appears the pipes are doing what they should. at least I think.

Hose next to battery with the valve (hi side I think) is hot.
Smaller tube next to fire wall and thicker tube with (hi side, i think) , is ice cold. but still no cold air.

any ideas?

[j cAT]

Originally Posted by TCHRISD

well I let it run a bit and it appears the pipes are doing what they should. at least I think.

Hose next to battery with the valve (hi side I think) is hot.
Smaller tube next to fire wall and thicker tube with (hi side, i think) , is ice cold. but still no cold air.

any ideas?

sounds like your compressor is working. if you had condenser warm and the evap pipes warm or cool then this would indicate a bad compressor or not much refrigerant. since the pipe temps are good cold and hot I would suspect a temp door blender is the bad part. check that you can get this system to produce hot and cool air when changing the temp.. these type controls fail often.

the condenser is up by the radiator.. the evap is in the firewall..

[TCHRISD]

Originally Posted by j cAT

sounds like your compressor is working. if you had condenser warm and the evap pipes warm or cool then this would indicate a bad compressor or not much refrigerant. since the pipe temps are good cold and hot I would suspect a temp door blender is the bad part. check that you can get this system to produce hot and cool air when changing the temp.. these type controls fail often.

the condenser is up by the radiator.. the evap is in the firewall..

When changing temp,,,,, I will get heat fine when on hot but when put to cold it just blow as if the A/C button is not pushed.
How would I check the temp door blender?

[j cAT]

Originally Posted by TCHRISD

When changing temp,,,,, I will get heat fine when on hot but when put to cold it just blow as if the A/C button is not pushed.
How would I check the temp door blender?

if when set to cold and the temp with the AC off is the same as the outside temp then you will require this be checked out by an ac shop. could be something wrong elsewhere need to hook up pressure gauges and confirm the systems proper operation and charge . could be air got into the system ..

[jyount]

If air got into the system it has leaked refigerant out somewhere. Air doesn't appear without a leak. The temperature change is as follows.... compressor/high pressure side(gas, hot)->condensor high pressure(gas condenses to liquid, starting hot to warm)->orifice tube(very cold after this, changes high liquid to cold low pressure liquid)->evaporator (low pressure liquid to cold gas, still cold)->out to the accumulator (both dries by way of a dessicant and keeps from slugging the compressor with liquid, it can't do liquid at all, this prevents it)->low pressure gas to compressor/low pressure side, cycle repeats.

The state changes(liquid/gas) must happen, either gives off heat or takes it in with each. ALL air conditioners work on these principles, from early a/c to modern. Just some different parts. If the temperature changes somewhere different than the above it either signifies a blockage or not enough refirgerant.

If you can't grasp this theory don't attempt it, and don't just add refrigerant either. That will only fix a system that is low in the first place. It would be much cheaper in the long run to get it repaired by someone knowledgeable. I know I sound like a broken record, but I was a tech and am IMACA certified. I am not fishing for money, but not kidding those that tamper with a system and don't understand it end up costing themselves more money.

Like jcAT said you need a Hi and Low pressure gauge set to even begin to properly diagnose an a/c system.

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