Hey everyone.

It is 73 °F with 62% humidity earlier today. I turned on my a/c and it wasn't cooling. I have noticed that the a/c would work intermittently on my TSX.

With the engine running, the compressor clutch is engaged and spinning. Both fans on the radiator are running. Blower in the car is working.

Hooked up the pressure gauge on the high and low side. Both read 60 psi with the engine running at idle (750 rpm) and is stable.

When I shut the engine off, both sides read 75 psi.

Checked for HVAC codes and have no codes.

I think I have a bad compressor and wanted to hear if everyone agreed. A low charge is another possibility.

 

I think there's a pressure switch, so with a low charge your compressor clutch wouldn't engage.

 

I figured the compressor would cycle on and off with an undercharged system.

I wanted to get a second opinion to make sure I didn't overlook something simple and verify that the equal pressures on both sides means the compressor is not spinning internally.

I still have a charge, so either the clutch is not connected to the compressor shaft, or maybe have a leak and a low charge.

 

I don't know what the pressures SHOULD be, but when it's not running the high & low will equalize to each other. So if your pressure switch was bad, it can prevent the compressor-clutch from engaging even with a correct charge.

Bad connection/wires at the pressure switch?

 

usually equal low and high sides when the system is engaged is a telltale of a bad compressor.

 

Yes, I forgot the part where PA said "compressor clutch is engaged and spinning"...

Can you pull the compressor clutch? I don't know if there's any way for the clutch to come loose from the compressor shaft?? Is there a key or something?

If the shim stack on the compressor clutch needs to be adjusted, then I think the hub of the compressor pulley won't spin. Only the rim of the pulley, just as if it was disengaged.

 

it could be a bad clutch, but since he has pressure readings that are consistent (as far as we know) it's probably the actual compressor bad. a defective/slipping clutch would give erratic pressure readings.

 

Equal pressure readings suggest the compressor clutch is not engaging. Do you hear a firm click and observe the clutch plate (inner part on the end of the compressor) turning at same speed as pulley?

The TSX compressor is a scroll compressor and Acura has had some problems (particularly w/ 04 TSX) w/ them. If compressor is engaging, I would suggest disabling until you can replace the compressor. It may be shedding material into the downstream system; aluminum pieces from scroll.

I had a scroll break on a Subaru Compressor where it joined the drive shaft. It locked up however and threw the drive belt quite quickly.

good luck

 

he's got different pressure readings with the engine running and then off...indicates something is happening.

 

The clutch plate is definitely spinning with the compressor pulley. I didn't observe any slipping. I hear the click as well.

I didn't realize the TSX used a scroll compressor, I just assumed it was a piston compressor.

There are splines on the shaft that the clutch plate slips over. Then a 10mm bolt holds the plate on to the shaft (like the CV joint and hub connetion). My next step will be to pry/pull on the clutch plate. If the plate comes off, then that shaft snapped.

The next step would be to have a shop recover the R-134a. They should be able to tell me how much they recovered.