Automotive Air Conditioning Information Forum

The car is a 2009 BMW 328i. These are the numbers after it was recharged:

Outside air temperature: 79 degrees
Vent temperature: 36 degrees
Low side pressure: 29 psi
High side pressure: 157 psi

Obviously, 36 degrees out of the vents is pretty awesome. How are the low and high side pressures? What would be the symptom(s) of having too much oil in the system? It seems to be working well at this point, but I'm just wondering what the 'normal' low/high side pressures would be.

Thanks in advance!

Jim B wrote:The car is a 2009 BMW 328i. These are the numbers after it was recharged:

Outside air temperature: 79 degrees
Vent temperature: 36 degrees
Low side pressure: 29 psi
High side pressure: 157 psi

Obviously, 36 degrees out of the vents is pretty awesome. How are the low and high side pressures? What would be the symptom(s) of having too much oil in the system? It seems to be working well at this point, but I'm just wondering what the 'normal' low/high side pressures would be.

Thanks in advance!

Normal pressures depend on engine rpm, whether the fan clutch/electric condenser fans are operating properly.

If it's 36F out the vents, don't do anything !!!
If it's 36C out the vents, punt !

Cusser wrote:Normal pressures depend on engine rpm, whether the fan clutch/electric condenser fans are operating properly.

If it's 36F out the vents, don't do anything !!!

The pressures were measured at idle and the fans seem to be working properly.

Yeah, 36 degrees Fahrenheit; I'm pretty happy about that. I measured 46 degrees Fahrenheit out of the vents of my Subaru a few days earlier and felt that was cooling just fine.

The high pressure sounds a little low, suggesting it's a bit low on charge. Drive it for a while and see whether it shows symptoms of evaporator icing. If not, leave it alone and enjoy the "cool."