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Hi everyone,
I’m having a very hard time diagnosing an intermittent problem with the AC in my wife’s 2008 saturn vue. Most of the time it works perfectly, but once, maybe twice a week, it will cut out (blows warm) when she is driving somewhere. The strange thing is – the AC will function properly the next time she drives the car. For example – the AC will work fine on her way to work…then it doesn’t work when she goes to lunch….then it will work fine 4hrs later on the way home.
This is what I have checked so far:
-The refrigerant levels/pressures are within spec for both the high and low sides of the system.
-The AC clutch properly engages/disengages
-I’ve checked all of the fuses that are used by the AC system…all are OK.
-There is no CEL
-I changed the cabin air filter a few weeks agoPersonally, I think this is an electrical issue of some sort. Whether it be a bad connection, faulty sensor, or a failing relay.
From reading around, a couple of ideas that came up in other posts included: a failing AC compressor relay, or perhaps a failing coolant temp sensor?
I do have a PowerProbe and a multimeter…so I am equipped to do some electrical diagnosis. Any tips or suggestions would be greatly appreciated. Thanks!
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Ok – I think we are getting somewhere.
I ran the car this morning for a few minutes, and I was able to get the AC to stop working again. I checked out the expansion valve, and this is what I saw. I think I have found my problem! I’m getting conflicting info on whether this is caused by moisture in the system, or because of a blockage in the expansion valve? Before I recharged the system, I put a vacuum on it for 30 minutes…that should have been long enough to remove the moisture right?
Based on what I’m reading, you might want to replace the expansion valve. Be sure to have the refrigerant recovered at a shop before you begin the replacement. You might also want to put it on an extra long vacuum after you complete the repair just to make sure you got all the moisture out.
Keep us posted.
I purchased a new OEM expansion valve and I’m having a repair shop install it tomorrow. I considered installing it myself, but given that I have to take it to a shop to have the refrigerant recovered anyways….in the end, I’d only be saving myself something like $75. The shop quoted me $125 to do the recovery, install the new valve, evacuate and recharge the system. I guess I got a little lucky with this car – the expansion valve is on the fire wall, in the engine bay….no need to tear apart the dash to get at the evaporator.
I’ll post a final (I hope) update soon.
Thank you to everyone who has replied to this thread – and a special thanks to Eric and College Man for their continued help and support! 🙂
CHECK THE “HIGH PRESSURE SWITCH’ BET IF WHEN IT STOPS AND U DRIVE 30 MINUTES AND CUT BACK ON IT WORKS, LET ME KNOW.
JOHN
[quote=”college man” post=106361]Glad to be of help. keep us posted on your progress. :)[/quote]
It seems like the expansion valve was in fact the culprit. I had the new valve installed on Wednesday morning, and the AC has been 100% ever since. I will post again in a week or two, just to confirm that everything is still working 🙂
I think we did it guys! Great work! banana:
I am having the EXACT problem. I am not as technically say as you, but I don’t want to be bent over the hood by a dealer or shop. Summer in southern Colorado. Parked in the sun the past few days. Drove it to town this AM and it stopped getting cool within a few minutes. I happened to be parked in the shade for 1/2 hour and boom! Ice cold. Parked it at home, under the shade tree with the engine still running and checked under the hood. All fans running, no indication of icing (that I could see.) This has happened off and on since I bought the car last fall from my son.
ANY help would be greatly appreciated.
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