My system was empty. I replaced the compressor and dryer. It should have 24oz (two cans) in currently less what remains in the gauges. Low pressure side Image Unavailable, Please Login high pressure side Image Unavailable, Please Login I think the only explanation left is the expansion valve not working correctly. The temperature differential should be much greater based on the pressures. After experimenting with the HVAC going from cold to hot to cold to hot back to cold I can hear parts move inside and the airflow sound also changes. I get heat and not heat. My pressures where right where the WSM says they should be Image Unavailable, Please Login
Is there a chart which tells you what the likely temperature differential would be or is this based on experience? I'm trying to figure out what those two points are where you are taking your temperature readings. The manuals aren't helping Image Unavailable, Please Login Is the temperature drop across the expansion valve, or is the evaporator in there somewhere? Thanks.
Update - I decided to measure my BMW A/C static pressure, low and high. Static was 90-95psi! Low = 30-35psi, high = 150psi. So I made the decision to add some more refrigerant! As soon as I did, the high pressure started to rise to about 190psi when I heard a fan on the condenser side come on and it dropped to about 140psi. I watched it repeat 3 times and thought - it's working! I check the inside temp and it was starting to cool! So I added another shot and check the inside temp. I would ad a shot and check the inside temp until I got down to the mid 40s. Today I went out and measured the static pressure (approx. 75psi on the high side). They should be equal after 20 hours! Image Unavailable, Please Login Is this conclusive evidence the expansion valve stopped functioning? Clearing the gauges and starting over: Now I am starting to wonder if I can trust these gauges! Image Unavailable, Please Login Started the car, running the A/C. High-high (190psi) - condenser fan comes on Image Unavailable, Please Login Low-high (145psi) - condenser fan shuts off Image Unavailable, Please Login cycle repeats 3 times in about 2 minutes. Video to big to post... No cooling! Image Unavailable, Please Login Seems like gauges work and expansion valve doesn't. Is that correct?
Earlier in the thread, I showed that my compressor was "weak". Very low high side pressure and adding fluid didn't help. "they" say, anytime you break into the system, its a good idea to replace the dryer. I have not heard otherwise.
Ok so much freon do estimate is in the system now? Have drawn a vacumm on the system with a vacum pump to draw any moisture out of the system for at least 30-45mins?
more than 25, less than 29oz. < 2.5 12oz cans. It definitely did NOT work with 2 cans. I drew vacuum for about 30 minutes immediately after connecting the compressor and let that sit while I installed the compressor. NO change in pressure. I drew vacuum for another 30 minutes, then walked the dog and got dinner. NO change in pressure. I drew vacuum for another 30 minutes prior to filling the system. Total vacuum about 90 minutes over 4-5 hours without any noticeable change in pressure.
Ok Now we have a little more information. (Did you check the oil level in the replacement Ac compressor before installing) First an understanding of how the system works and how to diagnose. Second, you replaced a possible faulty compressor which could have also clogged the system. You will also need Some special tools, a quality manifold gauge set, tool to pressurize the system Google knowlege Amazon for tools Good luck
I am a bit of a loss on how to remove the expansion valve cover without damaging anything! It seems like it might be sealed but it seems absolutely solid. Image Unavailable, Please Login
In the parts manual, I see a bolt/screw at the bottom, but I'm not sure what that thing is in the top rear corner.. Image Unavailable, Please Login If you do find a way to remove it, can you take a photograph of the cover for us? Thanks.
Nevermind... found some pics... Image Unavailable, Please Login Image Unavailable, Please Login Good luck getting to that top bolt
