Does the Hot/Cold AC knob turn without any force, or is it very hard to turn? Either of those extremes is a common problem in the Z3. The temperature control tension cable in the dash becomes stuck at the far end, causing it not to operate correctly.

 

Yes, its very smooth and the clutch does engage/disengage when turning the AC snowflake switch on and off. But the fact that there is big pressure on the low side suggests the compressor is not pulling.

 

or the freon level is low.

Fred

 

Its probably low freon. Had to charge mine when I bought it. Dont expect it to be escalade type comfort inside though, doesnt hold the cold in too well.

 

If his low side is way high, and the high side is a bit low, it sure seems that the compressor isn't compressing, or possibly the expansion valve is totally closed or blocked up.

Before replacing the compressor, I would have a knowledgeable A/C person have a look to make sure the compressor is being "called for" and for other less costly possibly problems.

EB

 

or possibly the expansion valve is totally closed or blocked up.

My bet would be on a blockage somewhere on the low side. Slightly low high-side pressures tells me the compressor is doing its job. Pegging the low-side guage seems to indicate that there is never any expansion happening. High side becomes low side at the expansion valve.

 

a can of freon is a lot cheaper than a compressor, mine leaks from the O ring, from where the lines enter the compressor. I need to change them but right now two cans of freon is alot cheaper than the service call

 

Was your system opened recently (by the previous owner?). What engine speeds are you measuring the pressures? If at idle, run the engine at 2000 rpm and hold while you are measuring pressures. The pressures do change, so worthwhile checking. As indicated above, you could be low on refrigerant. With your manifold gauage set, you might want to try adding a can (hold the can upright - shaking periodically between 12 and 3 o clock positions OK), while carefully reading the pressures (engine at @2000 rpm). If these things do not work, prior to deciding to change compressor, you could take it to a shop and have them evacuate the system, pull vacuum for you (unless you have a pump); I assume you will not have a leak. If you do, change the o-rings after the shop evacuates your system, then pull vacuum. You could have excess moisture in your system that results in your evaporator freezing and causing blockage, leading to higher low side pressures. Not to mention that moisture is bad for the internals of your system. Pulling vacuum with a good set-up will eliminate the moisture. Does your condensate line drip freely?

Just some random thoughts at the moment; I am sure there will be some clarifications.

 

ALL AIR CON'S NEED TO BE RECHARGED FROM TIME TO TIME PROBABLY YOUR PROBLEM
PS SORRY ABOUT THE CAPS I DONT HAVE MY GLASSES WITH ME

 

My two (2) cars are nine (9) and eleven (11) years old, and still blowing cold.

The refrigerant isn't consumed by the process; if there are no leaks, which is normal, then you don't need replenishment.

You also don't want to overcharge an A/C system. While it has been years since I worked on them, I was once a (paid) expert on them too

 

Not a problem its very common take the car in to a dealer and have the system recharged
simple peeps init!!

 

We determined that our manifold gauges were not working. With a new set we are getting 40 psi low side and 150 psi high side after adding a shorty can of 134. Its making water but leaking onto the passenger floor. And we have just figured out the condensor fan is not kicking on. Does anyone have any suggestionos on how to t-shoot that fan circuit? I have ordered service manuals and a DVD but they have not arrived. Any input appreciated.


EDIT>>> Auxiliary fan fuse #16 was blown, fan is running now. Maybe a tad cooler but still not right. So maybe I need to go have it competely evacuated and recharged?

Jim

 

Leak check showed a leaking evaporator. So I pulled the core (much easier than most I have done) and the coil was clearly leaking. So I have new a new evaporator, expansion valve and drier I'll be installing this weekend.

 

Randy is of course correct. It's also worth noting that BMW doesn't let the dealers recharge the system more than once under warranty. A second recharge means a leak that needs to be fixed. In my case it was the condenser, 7 years ago (took a stone at high speed).