I have been on the forum for quite some time looking at the posts about air conditioning not working well when stopped in traffic. My car is experiencing the same problem. I have done all of the checks that are mentioned in the posts I have read. Freon was checked by me and a professional, pressures on both low and high sides are good. Radiator cooling fan is working as it should, high and low speed, no apparent leaks in the system, no blockage in the air flow through the radiator or condensor. Cools great at highway speeds, not so great sitting still. When sitting still, I put in neutral and hold RPM's at 1,800 and it doesn't improve the cooling. So, I don't think that the compressor is going out. It appears that it has to do with air movement through the condensor. I am at a loss on this one. Thanks for any help you can give.

 

Well, that's an interesting fault. There is a smog sensor, but AFAIK this only switches to recirculation. Other thing is electric load optimising, but the compressor is not electrically driven. A bit of a puzzle !

I assume you have it set on full AUTO. Try going to manual fan and see what happens.

 

Fraser, I have tried both full auto mode, full auto with recirculating, and full manual blower speed. No change in cooling when sitting still. All modes work well when moving forward and air pushing through the condenser. The problem is not enough air going through radiator/condenser . Radiator fan working is working properly. Can freon go bad after 7 years? Thinking of evacuating the system and recharging with new freon. Nothing else appears wrong with the system.

 

Hi ndw,thats what i would try first,im an airconditioning technician (full title workshop manager for a company called advanced radiators up here in newcastle upon tyne uk) and your fault sounds like the classic symtoms for lo ac refrigerant(r134a)and as you can use up to 20% each yearthrough natural wastage a re charge
Would be well worth a try
Hope this helps
Thanks dave bennie

 

Dave,

I am going to get that done this week and will report back if there is an improvement. It is currently 108 degrees in Texas today, so it will be plenty warm enough to charge the system! Thanks.

 

I added one can of our one 3480 this morning. I decided against a full evacuation and recharge. Low pressure was 40 psi at 82° ambient temperature. Decided to add a full can knowing the high limit switch would kick in if I over pressurized. It took a fool can and low pressure remained at 40 psi after the fill. Now the air is cool at stop and highway speeds.

 

R 134 A. Dang Siri and auto correct!

 

I'm not sure if the humidity in TX is high. But Humidity is very hard to
condense especially at idle. That could very well be a contributing factor to the A/C issue you are having.

 

Humidity is pretty high here, but with 106 degrees outside yesterday and high 80's % humidity it was cooling like a champ.