HVAC Fun and Excitement

[Jberger]

Well folks, Today was exciting, thought it might be my last Q trip.

I had a small road trip (2hr) to a client meeting and decided to take the Q. Noticed about 3/4 of the way there that the AC was simply not cooling. I thought that is seemed a little weak in the past few weeks, but since I really haven't driven it much, I never noticed.

Since I was not looking forward to the ride home without AC I dropped it off at a Firestone Auto Center (yeah, I know, they suck, but they were in the same area as my lunch meeting).

The Firestone guys proceeded to preach gloom and doom regarding replacing the compressor, evaporator, refill the freon, etc. Oh, plus a fuel system cleaning (like that was affecting the AC?!?!). All for the low low price of $1,600. Naturally I laughed and said no, 40 bucks later I was out the door and back on the road.

Now, here's the best part. When I restared the car, the AC worked perfectly, I mean COLD!!!

So, any ideas as to what was wrong?Hung clutch? Stuck Relay? Loose Wire?

[maxnix]

Check the pressures. May be ultra low so it seems ultra efficient until the evaporator core and expansion valve freezes solid and it quits working.

How long since you have done a Freon and oil flush with a drier replacement?

[Jberger]

Had the entire system reworked, by the dealer (it's the only job T3 recommended the dealer perform) about 2 years ago. Including a complete system vac. and 2 dryer exchanges.

The system worked fine on the 2 hour drive home, so I'm guessing it was something loose or stuck.

[maxnix]

Well, I would still get a high and low pressure reading to see if any charge has leaked. Two years is a long time.

[greg_atlanta]

They probably sucked out the freon and put it back in.

I had same effect in May 2001 when my A/C wasn't working great... went to dealer, they said "need new compressor, $1200+"... I declined the work, and then it worked fine for 2 years!

Might have been junk in the system that they cleaned out by hooking it up to the machine.

[Jberger]

Well, had even MORE FUN today!

Quick trip (10 mins) over to a clients office and the air goes out again, only now there is a rubbing/grinding sound from the front of the engine and I think a bit of smoke.

Turned the AC off and the noise was reduced, but not completely eliminated. Checked it out a few minutes ago when I finally got home. The sound appears to be coming from the compressor. Any chance the compressor clutch is stuck? That's the only idea I've got left.

[float_6969]

I think it has something to do with the compressor. If the clutch was stuck, it would just turn the compressor and your AC would be on all the time. If you had some bearings going out though, you might be getting the intermitent problems you are having now. I would make sure that the noise is coming from the compressor first. If it is the only thing on the belt that runs it, try taking the belt off and see if the noise stops. While you have the belt off, turn off the car and see if pully on the compressor turns freely. With the car off, the pully should spin but the center shouldn't turn. It should be VERY easy to turn. If it's not then something is wrong with the compressor.