Jeffrey Ellis

Need Help with AC Problem Edit | Quote | Reply 2014 Silverado 1500 w/5.3L Ecotec engine.
Replaced the following:
Compressor
Condensor
Expansion Valve
Low side line w/two mufflers
High Pressure Switch

AC is cooling great, but having two issues:
1. whirring sound when ac is on-

When AC is running and I accelerate, I'm hearing a whirring or whining sound. It sounds like it is coming from the passenger side around where the evaporator is.

2. low side line frosting up where line comes out of expansion valve-

I have vacuumed and verified there was no leak when setting this up.

One of the things I have noticed is after the initial charge (around 25) the compressor clutch is engaged and I have not noticed the compressor cycle off and on again.

I'm learning that as a DIY, this AC fix is becoming more complicated then what I had anticipated.

I could really use some help, pointers, tips, etc.

oilcanhenry

What are your low and high-pressure readings with the vehicle warmed up?

Jeffrey Ellis

Low: 45-50
High: 155-200

Radiator fans turning full speed

Frosted low side line where it connects at the expansion valve and the muffler on the low side is frosted up.

oilcanhenry

OK, thanks for that. Your low-side is running too high for some reason I haven't been able to determine the possible cause yet. 40 to 50 PSI is simply way too high. Your high side seems normal enough and in fact could be higher in the 220 PSI range. Given that you have changed out so many parts of your A/C system, I have been scraping my head trying to figure this problem out. You say your system has two mufflers makes it even more difficult of an issue as I have never seen such a system, Chevrolet or not. My 1998 K-1500 has only one, and I've not seen that on any vehicle. There are only two things that come to mind, which would be air in the system or a faulty Asian part of which I have seen many over the years, since we no longer make parts in North America.anymore and the Asian parts can be okay or not. Your low-side frosting up is of real concern, at normal outside temperatures, to be certain. My best guess is that your compressor was not properly made or remanufactured. even if is new. It was made in Asia and that, these days is hit or miss The evaporator should not be making any noise as it's just a reverse radiator, blowing out cold air, not hot at all.
Is it possible that you have an interior fan issue, as that would indeed explain the noise that you are hearing, should it be worn-out?