hooger

Yesterday was a beautiful, but very hot, day and i made plans to go on a nice long drive with a friend of mine. We started the drive and I noticed that my A/C wasn't cold. I left it running because there were some bursts of cold coming out and then it eventually just stopped blowing cold altogether. I still wanted to drive so i rolled the windows down and drove around all day in 97 degree heat. I guess it was good practice for the glen.

Anyway, this is the first time I am using my A/C since I had my engine/trans out because I had my fittings welded, LSD rebuilt, all pulleys, belts, and hoses replaced, water tank replaced, and some other things while the engine/trans was out. The A/C was working before I had all this work done.

I am able to see that when the A/C is enabled from cockpit, the bearing on the pulley starts to spin and stays spinning. When the A/C is turned off, the bearing stops spinning.

I also measured the low pressure on the refrigerant and its off the charts. I don't have the proper gauge to measure the high.

Has anyone seen this type of behavior and could help me get to the bottom of it. I am also sending an email to my indie but since they are closed on the weekend, I'll have to wait until tomorrow.

Any suggestions? I'm really hoping its not the compressor, but it seems like the clutch engages which I am assuming also means that there is enough refrigerant in the system.

Macster

The symptom blowing cold at times then blowing warm is one I experienced years ago with another car. Turned out to be low refrigerant.

Given the system was opened up when you had the engine work done I'd offer the possibility a seal is bad and this is why the refrigerant is low.

BTW, my info is it is not a good idea to run the A/C if the system is low on refrigerant as this means compressor oil is not circulating and the compressor can be damaged. I'm not sure if the newer systems refuse to engage the compressor if the pressure is not right but I'd not gamble a very expensive compressor to find out.

So before you recharge the system my advice would be to have the A/C serviced by a reputable A/C shop.

There the A/C system will evacuated and held at low pressure for the recommended time (used to be 30 minutes but this may have been upped to 1 hour) to ensure there are no leaks.

There probably will be a leak and this should be fixed and the system retested to make sure the leak fix took and there is not a second leak. (There are always two leaks unless there is just one leak or 3 or more leaks.)

Additionally holding the system at low pressure that long ensures no moisture is in the system.

Then the system is flushed with refrigerant to remove/capture the oil.

Afterwards the proper amount of refrigerant and oil is added back to the system and the system tested for proper operation.

hooger

where was your leak. do you know the place where these leaks are most likely to occur on these cars.

also, does anyone know of another car experiencing this after fittings or similar work where engine and trans are dropped.

Macster

You know I'm sorry but I do not recall where the leak was. I can tell you based on my 2nd hand knowledge the o-rings at the various couplings are the most likely to leak, especially if the unit has been apart.

However, just because the system has been apart does not mean it will leak. I've had the A/C systems in both cars apart (well, the dealer had them apart) to deal with the result of hitting some road debris with one car which took out a radiator and condenser and with the other car a mule deer impact which took out a radiator and condenser (along with a lot of other stuff). The one car had this road debris taken care of years ago and the A/C system still works just fine. The car that hit the mule deer had this repaired in June of 09 and the A/C system blows cold just like before.

Even if the unit has not been apart, they can leak too if the unit is not used very much. The o-rings dry out and leak.

But any fitting can leak.

Another possible leak is a condenser, especially if you tell me you haven't keep those radiator ducts clear of trash. The trash holds corrosive moisture at the condenser which can have it (and the radiator) leaking from a hole due to corrosion.

A rock can hole a condenser too, of course.

Anyhow, a special dye can be introduced into the system and with IIRC a black light used to find the leak. This eliminates the guesswork of where the leak is.

jtt777

What causes the low pressure side to have such high pressure but it appears than the clutch is engaging? No new refrigerant will want to enter the system because the pressure is too high to flow from the can to the low side.

Is there any way an "empty" system would do this? Perhaps the last service introduced air into the system? Would that cause high low side pressures?

The air coming from the ducts in this case is no longer cold at any point. It doesn't occasionally work...

hooger

when the shop vacuumed and filled my refrigerant, their machine was on the fritz. So they were able to empty it fully, but apparently it was not properly filling. So i basically just had no refrigerant. They got a new machine in the last week and they redid the entire procedure and now its blowing 38 degrees pretty much idle.