Sisters 2003 Protege5 AC not cool enough. Any way to check for refrigerant level w/o gauges? How cold should air from vent be? What kind of refrigerant was used when new?
Is that still available? What Kind to use now? Does system need to be flushed if different refrigerant is to be used? How about refrigerant oil? Is it combined with the refrigerant sold at autosupply stores?

The belt is good and not slipping. Clutch engages, Anything else to look for?

Is there an air filter for the AC/Heating system How to change it?

I may take to shop, but want to be better informed if I do so.

 

I'm not aware of checking pressures or gas level without gauges.

from experience a 2003 should be running R134a refrigerant.

When a system is worked on, all the remaining gas is evacuated, added to the service tools storage cylinder & reused later.

I'm not aware of any flushing, however if the system has run dry ( full leak out ) the reciever drier will need replacing. Then the system is vacuumed, pressure tested with nitrogen then refilled with the correct amount of R134a & set amount of compressor oil.

You can test the output of cold air by running the car, heater on cold & A/C, centre vents, fan speed 2 or 1/2 setting, recirculated air, doors & windows closed, place a thermometer in the vents & leave for 5 minutes. Should drop to 6 or 7 degrees Celsius.

 

The temperature coming out of the vents is 12.6 C, 55F in 100F weather. I took it to the shop. They determined there were no leaks. The pressures were 40/220 psi which they said were normal. They said it was not cooling because of the high humidity. Whaaat? I used to live in Houston Texas where it is always extremely humid. You could not sell a car if the AC did not run cool, No, Cold. Is there a cabin air filter in this car? Anyother reason for it not running cold? Could there be a control module that is not alowing the compressor to run long enought? While on the subject, is R134a as effective a refrigerant as R22?

 

I removed a sensor from the chamber between the fan and the evaporator coil. There is no cabin air filter. There is a rectangular piece gluded in on the bottom of the plenum where a filter might be installed, and is installed on some models. The evaporator coil is about half gunked up. Not just dust, but sticky gunk, so can't imagine how to clean it. Looks like a very hard job removing all the air handling stuff to clean it. I am not good at working behind dashboards so it looks like a very expensive job to get done. Any ideas about how to clean it?

 

I would recommend getting it re-gassed.

 

Why? Regassed with what, all new Freon? Does Freon degrade with age? I think the first thing to do would to be clean the evaporator. It is 50% blocked to airflow.

 

Most auto parts stores sell refrigerant in small cans plus you can buy an adaptor hose with a gauge on it to fit your car's low pressure side schrader valve. Follow the instructions on the can but I think it is a simple matter of hooking it up, have your AC running, turn the can upside down, open the valve on the adaptor hose and let the refrigerant enter the system until the gauge needle is in the upper portion of the safe area. DO NOT OVERFILL!

Entire process takes 5 minutes max. and costs about $25. Even if you have a tiny leak (likely at that age), a top-up only will cost a few dollars and likely lasts months.

If your vent temp. is 55F, then there is nothing wrong with the system and the car will definitely cool down over time on a long drive. If you get into a hot car that had the windows closed and only drive a short distance, the system will only seem barely adequate. Don't forget that EVERYTHING inside the car may be well over 100F. Have your sliding vent control set to RECIRC for the first 10-15 minutes; the air that is cooling down inside the cabin goes back thru the system and cools quicker than fresh outside air. Remember to eventually slide the control back over to NORMAL which brings in fresh outside air as the cabin will get a bit stuffy on RECIRC over time. RECIRC is a great way to prevent those stinky diesel fumes from getting in from that truck or bus in front of you!

Checked my vent temps. yesterday after several minutes and easily saw 40F so likely your system only producing a low of 55F is low on coolant.

 

clean the evaporator and the fan blades. also, check that both radiator fans are working properly. one of the fans should turn on every time the ac compressor engages. if the fan is not working, the ac wont cool as it should.