I checked the pressure of the A/C system, and it's at a healthy 45 PSI (or around that), the inside light stays on (doesnt blink like some people have had issues with) but after about 5 minutes the A/C clutch and fan turns off and then back on for a few seconds, and off, and on, and off, and so on.

What is causing this? my sister just bought this car with 97k, and it's doing this a day after she bought it.

FYI it's an '03 manufactured in 2002.

 

Don't they all do that? Granted I don't use A/C all that much up here in New Hamster, but every car I've ever had, regardless of manufacturer, has cycled on and off once the evaporator and/or the interior of the car is down to a certain temperature. Am I missing something?

 

yeah it blows out hot air and the car heats up quickly.

rather, the interior gets hot, not the engine.

 

Ahhh, well in that case, I thinks she's broke. Time for an A/C professional to have a look-see.

 

but it's weird that it's good for the first 5 minutes, then starts doing that.

leave it off for 2 minutes, and it's good for another 5.

it's either a thermostat issue or the reciever-drier.

but yes, A/C shop time.

 

what.

damn spambots.

 

People get stuck on the fact their system has enough refrigerant and forget the fact that it can have TOO much. You need to check the low pressure (what you are checking now) and the the high pressure port. If your pressure is too high, it also trips the clutch to disengage. The problem you are reporting is a textbook example of how the compressor acts with a slightly overcharged system or a system in which the dryer or inline filter is partially plugged and tripping the high pressure switch, or has a faulty high pressure switch.

I bought this cheap set just to diagnose my similar problem on my Jetta:

http://www.harborfreight.com/a-c-man...set-92649.html

and yes-mine ended up having a good low pressure of about 40 psi, but my high pressure was close to 300psi when it should have been about 200.

You may only see it this problem when it gets extremely hot, because the increased ambient outside temperature drives the pressure of the system up slightly.

 

yeah it's just slightly over 45 PSI when the system is running (like 46, 47 PSI) and 65 when it's off.

I haven't tested the high port yet.

but yeah, I told her to take it to an A/C shop.

my bmw hasnt had any issues and it's just a little over like this.

though on an unrelated issue the engine exploded on my bimmer. stupid previous owner. So I cant say it hasnt had *ANY* issues