Ac Weirdness And High Compressor Readings

[snuffy smiff]

My AC starting acting up a couple months ago. Just about the time it started to get REALLY hot, of course. Still works but sometimes at idle it'll go totally warm. Raise the RPMs up and it'll start cooling but it seems to take longer to cool the cabin down now than it used to. Then at other times it's like a freezer in there! I keep having to back it down. This usually happens when I've driven it more than 20-25 miles or so.

So I go see a buddy who's a mechanic and we got to talking about it. He wondered if maybe it was low and in need of a charge. So he put his gauges on and then gets all bugeyed. They're showing what he considers to be way too high pressures. High side is bouncing on up past 500 PSI and low side is on up past 200-hitting like 280 more than a couple times. Buddy asks if any hoses been blown off yet. Nothing bad has happened in 56,000 miles so far(knock on wood).

 

Guess what I really need to know is are these pressures normal? My buddy hasn't worked on any truck of this late model and while it's acting different than it has in the past, nothings broke yet. He's stumped and I don't know enough about this to figure if I ortta be worried, just keep on cruising(fall is right around the corner) or start saving up for some major repairs. Any ideas?

 

Thanks much,

Snuffy

[bobcat5544]

500 high side and 200 low side are way to high. The readings should be in the area of 160-213 high / 35-47 low side at 86-95 deg with 50% humidity or 196-246 high side / 37-52 low side at 96-105 deg with 50% humidity

 

Possible causes AC Condenser has inadequate airflow, Engine overheating, Freon overcharged, Bad Orifice tube, Bad compressor (only if it a verible displacement compressor), or Bad High Pressure switch.

[ZZ327]

maybe check your cabin air filters too?

 

Im working on a pickup that has this similar problem

[atboley]

the first thing you gotta check is the orifice tube, could be clogged with metal(located on the right rear of the engine compartment) just a screw fitting that comes apart and there will be a filter like thing inside the line, pull it out with some needle noses( be sure to take the freon out first tho, duh ), buut that is most likely the cause, if there is metal in it replace it, then worry about where the metal came from later, because that most likely mean you got a compressor goin out soon...

 

And BTW, starting in 03 on C/K body trucks, they dont have cabin filters anymore

[Secret Squirrel]

Make sure your fan is working properly. With out sufficent flow through the condensor, the pressures will rise.

 

 

 

SS

[ewiski]

500 psi on the high side will blow somthing up.I highly dought that reading is correct.the belt should be slipping and sqealing like crasy at that reading.

[snuffy smiff]

Well, almost 3 years and 30K miles later and it ain't broke yet! (knock on wood-summer'll be here soon!)