Has anyone experienced this before? My a/c blows ice cold while the car is moving, but immediately kicks off when I stop at a stop light. What's the cause of this? Bad thermostat, relay?

e

 

all that you have listed are possible issues or it could be a bad clutch.

 

no vac , check for a leak.

 

Check the condition of the condenser... And the compressor.

 

Hey guys, quick update. I took the car in today to have them check the a/c. There are no leaks, but they said that the compressor is going bad. Does that make sense? Can a bad compressor still blow ice cold air when the car is moving but turn off when the car comes to a stop? Please let me know what you think. They quoted me $1,900 to replace the unit, parts and labor. Thanks.

e

 

i have the same issue or when i cut the a/c one the first line it blows hot always have to keep mine on two for it to blow cold

 

I had a problem where the magnetic clutch would disengage and the compressor would not be on. I would get a flashing light over the A/C button. I would check the diagnostics on the A/C . Hold Autoo and recirculate and cycle the ignition on this will take you into the ac diagnostic mode, it will dispay codes when it detects a malfunction do that and let me know what code it gives u. Should be a 2 digit number. Do this in daylight otherwise it will show a error for daylight sensor.

 

Thanks Spyder. I'll do that. Is there an easy way to take it out of diagnostic mode?

Also, I was looking at the Lexus estimate and they said I had two bad "read" valves. Does that mean the entire compressor needs to be replaced?

Thanks for your help.

e

 

To take it out of diagnostic mode just hit off on climate control panel.

 

What rpm is your idle ??

To low pump will switch off.

Time to clean your throttle body

 

e-man, the reed valves are internal of the compressor. Not serviceable. When gauges are hooked up with the A/C on the needles should be steady. If they flutter rapidly, this is a sign of the reed valves going bad inside the compressor.

As far as it turning off at a stop, you could very possibly have two problems. Possibly. If it were me working on it, I would convey to you that would definitely know the compressor is not working correctly, (considering we do have fluttering needles), and that we really need to address this first before we can properly address another issue.

Not working at idle sounds like you could "possibly" have a fan or air flow problem. But you really need to take care of the compressor first.

Hope this helps...

 

That helps a lot. All the things you mention are things the Lexus tech said to me. He said the needles were not steady and the levels were fluctuating. Both fans seemed to be working fine. Oh, and one other thing, when the compressor tries to kick on when the car is stopped, it makes a noise (like a baseball card in the spokes of a bicycle wheel).

Based on what you're saying, it sounds like the problem is internal with the valves, and the compressor is on its way out. One last thing -- when I rev the engine at a stop, the compressor blows cold. Does that mean anything? Thanks for your help.

e

 

just means that the compressor is struggling to make that compression internally without alot of rpm input. More rpm moves the reed valves fast enough sealing them and creating the pressure difference needed to make that lovely cold air inside your ride.

 

glad I could help

 

Okay, so now it's not even working that well when the car is in motion.

Spyder -- I did the diagnostics test. The first time I did it, I held the auto and recirc button and turned the key (but didn't start the car). The codes read 21, 24 and then 42 in succession. The second time I did it I actually started the car (which I think is what you wanted me to do) and the code read 42. Does that help you understand what's going on? Thanks again.

e