Just started to notice that my AC doesn't always cool upon start up. I had it evacuated and recharged about two years ago so I figured that I may have a small leak.

Hooked up a set of gauges and here is what I saw. The high side started to clime to 450psi until it shut off the compressor, low side was around 55-60psi. After about a minute pressures were around 175 on the high side and 85 on the low side. Right at the 1:50 mark the pressures start to stabilize at 45/260.



On a side not the AC usually works fine after a few minutes of driving. I've already checked the fan clutch and it appears fine.

I'm guessing a clogged orifice tube?

What do you think?

I don't even know if these have an expansion valve or are fixed orifice.

 

Weak fan would indicate high pressures on the low side right?


I deleted your other thread. More specific traffic here, and we only allow one thread per subject at a time. It gets confusing if your have multiple threads about the same thing.

 

A bit hard to tell when the compressor is engaged and disengaged based off pressures. The high pressures in the beginning tell me the fan clutch is not engaging. The point where the low side is about 80 and 175 is the compressor clutch engaged or not? Orifice tube doesn't look to be an issue with the pressures at the end. If it was clogged it'd either be bad all the time or fine all the time, it wouldn't alternate.

I think at 0:46 your clutch sounds like its kicking on and it sounds horrible. If that is your clutch the A/C compressor sounds like it will need replaced soon.

I personally believe the fix is to replace the compressor, at the same time I would replace the orifice tube and drier in case the compressor shat it guts into the line.