I did some searching around but could not find much info on my particular issue. I don't really know a lot about A/C systems so bear with me. So here's my problem: My A/C only blows cold air while the car is moving. When it's sitting still, like at a red light, the air instantly goes warm. When I start moving again, it'll go cold. I'm not sure how that affects it but one thing to note is that this started happening right after I installed a SOS supercharger system on my car. Some people actually told me it's because of the increased under hood heat and it's messing with the A/C lines?

Also, I have another issue that seems to be linked to the AC. Very often when the car is idling with AC on, the rpm start going nuts and starts fluctuating like crazy. It's just a constant up and down and every time it goes down, the car shakes as if it's going to stall. The minute I turn the A/C off, this stops. I know the A/C draws a big load but this also started happening after the SC system. Is my compressor going bad? Or is this some other, more simple fix? Thanks for the read and any insight is appreciated!

 

wow wish i could wright like that, sounds like its just low on gas

 

Shot in the dark so...

Make sure your A/C fan is operating correctly. It should run constantly when you have your A/C on. A/C works by air moving through the evaporator to cool the gas inside. If air isnt moving through then your A/C's performance will suffer.

Another factor could be increased temperatures under the hood. If you have low R-32? (cant remember the gas name) then it will trigger the low gas switch which would basically cause the system to stop operating. If you are just on the edge of tripping the switch the added heat could be causing it to go over that edge and trigger the low gas switch.

As for your idling issues I would say that is directly related to how your SC setup is running ie tune. Have you had it dyno tuned or are you running a safe tune?

 

Is the belt loose or old? Maybe the compressor is getting tired?

 

Check the cooling fins on the AC condenser, see if they have been sandblasted shut.

Just dealt with a similar issue, the bottom 8 rows were sealed shut.

IAC service (free up shaft, not cleaning) should be your first step with the idle.

 

Does it blow cold if you rev the engine and hold at say 2,500 rpm? If it gets colder with higher revs, most likely you're low on refrigerant, if it only cools while you're moving then I agree with Billman, probably got a bit of debris clogging the condenser. Does the A/C fan cut on when you engage the compressor?

 

I'm not referring to debris. The delicate aluminium fins get folded over, blocking the airflow. It happens from highway driving, and sandblasting from airborn sand. The higher the miles, the greater the chance.

This also affects airflow to the radiator, but typically will not show itself as a problem unless you track the car. If your temps are creeping up, check the ac condenser. You'll be amazed at how much damage it can have.

 

I did notice when i removed mine that there was a permanent layer of soot on it except where stuff is in front of it, like the bumper and the drier. Definitely had some clogging, but after 141k miles nothing was bent to the point it was obstructing air flow.

 

[attachment=85071::]

Mine with more than 200 k

 

Bump for a 6 year old thread lol

At 186,000 miles my AP2 started having the same symptoms as OP and with Billmans advice I have this same problem. My lower rows are pretty damaged. I will be ordering a new condenser.