2001 Stratus Sedan 2.7L V6 with 75K miles. Started with intermittent cooling issues and got worse. Bad belt or pulley noise as well. Decided to add R134a that included a pressure gaugeand then a severely cracked belt. Low pressure waschecked with fan setting high and vent position on A/C Recirculation and a pressure reading at 25 PSI. Added half a can approx 9oz. Currently system runs at about 30psi with system in high fan speed and A/Crecirculation. Cooling improved but not great so we replaced the belt. Here is the problem. Switching the vent position from A/C recirculation to any other A/C vent position the low pressure slowly climbs to above 40 psi. Also, when accelerator pedal is pressed, increasing RPM's, low sidepressure increases and clutch really pulls on the engine andwill not stay engaged (understood, to protect the compressor).Thenhad a suggestion from a neighbor that I reduce the tension on the new belt, which I did and that did not help. Now the compressor clutch and/or pulley squeak when I accelerate. Any ideas?

 

i'd say your first move was the right one. my '02 2.7 runs right at 45psi at idle(low side, doors open, a/c on full cold). this is the first time i ever checked it, noticed the car don't cool as good as it used to. BUT, it's a black car and the outside temp is pushing 100. keep in mind evan a great working a/c can only cool the air by about 20 deg.

tighten up the belt again, i think the noise you are hearing is the belt slipping around the pulley. when you put more R134 in was it the kind that had lube in it? the lube is for the compressor.sounds like you have some type of slow leak in your sys. you can get the R134 that has a uv tracer in it. try using this next time, you might be able to replace a seal or two to seal up the sys again.

the press change when you change the dash switch might be explaned by the following,if the a/c had been running enough to cool off the cab. if the inside of the car was cooler than the outside airit would take less energy to cool the air being pushed around the cab. once the intake moved to the hot outside air, the sys would work as much as it was able. this load change would show up as a higher press in the sys (it's like leaving the fridge door open).

the sys has quite a few saftey cutoffs. low press: cuts power to compress when R134/lube get low, on low press line;high press: keeps the sys from blowing its self up,on high press line;high power/rpm: same as high press, sig comes from eng rpm. some makers also put in a temp sensor or two in the sys. can be eng and/or a/c coolant, that's a bit above my head though.

i'd check the following also:
are ALL the eng fans comming on when the a/c is on? check the fan relays.
are the wires going to the compress tight and clean? look for rust/dirt that might make a bad contact.
can you freewheel the compress clutch by hand with the car turned off? this is a GOOD thing.
does the a/c work ok on defrost? this check will bypass a lot of the dash switches and tell you if the prob is in the dash.
pop off the dash controlls and look for loose/bad wires.

the sys psi should be under the hood on a sticker.

hope this helps. good luck.

 

The engine fans are both running and I can freely turn the condenser clutch. The R134a does have a leak sealant in it with compresser oil. The defrost is working along with recirculation. I thought it was strange when our A/C problems started, the defrost would blow really cold air but turning the dial to standard vent a/c it would blow warm air. I will investigate the electrical aspects. Thanks for the help.

Does this car have DTCs that can be read with a computer if I would find a part's store with the equipment.

 

you can go to autozone or any big parts chain and they will read the code for free (want to sell you the repair parts). don't think the a/c sys is hooked into the comp, worth a try. all newer cars use the a/c when on defrost as it helps dry out the air real fast, less fog on the inside of the windshield, not too good in cold weather when you first crank the car. any luck yet? happy motoring.