Thread: A/C not working in traffic/extreme heat!

Hey,
Live in jamaica its hot as hell here (to me atleast). Recently fixed my air conditioning system. Changed drier, oiled fresh sr20ve compressor, checked thermostat, changed fans, changeed condenser, and evaporator core, changed all o rings, checked gas pressure. A/C works fine while constantly driving, during the rain, or night.

The problem is I can feel the engine change when the compressor chips out (during traffic and hot like hell days), but the car is as hot as hell, so I can't figure out why the compressor keeps happening. One a/c tech says my 4-1 header is giving off too much heat. But > 60% of you guys run after market headers and a/c still works well.

What do you guys think is the culprit?

- So it works great when you are driving normal with not a lot of stops, but with "stop and go traffic" it gets hot?

Yes stop and go traffic it performs poorly, especially on hot hot days

RPM's are too low for the compressor to work efficiently. If you don't get the sweet spot with the refrigerant amounts you will be suffering like you are and I am.

Also if the system has been open for a while, with air in it, there is probably dirt and corrosion that needs to be cleaned out first.

If the system has been opened (at all), the filter dryer will need to be replaced. There's a reason they recommend a tech replace the dryer assembly, since vacuum needs to be applied and moisture removed from the system before charging it. If the dryer assy is exposed, the media inside is contaminated, and the system will never work the same again.

Your A/C should work relatively fine in stop and go traffic, as well as sitting still. You will likely need to evacuate the system, and recharge it. Don't just top it off.

- Ok. I feel better now that it's not just me. Must be our old systems, because I did my R12 to R134a conversion to the "T" and it gets warm in "stop and go traffic." Once I get back to moving, it's back on ice. New cars don't do this.

Sure they do. My 2004 WRX and 2005 Armada both have issues where it gets "warm" in stop-n-go traffic. That's just the inefficiency of R134's blend of freons, whereas R12 was not a blend but a single freon.

- No new car I have road in gets warm like my SE-R does, but I did hear that R12 stays/gets colder.

hey, before I spend money on a new drier and vacuuming and re-gassing, the comment of it being heat in the engine bay is unfounded? because when you put your hand between the engine fan and the compressor, wow its incredibly hot.

R12 works better in older cars because they were designed for it. R134 works "ok" in retrofits and better in factory systems because each system is sized for the car and refrigerant. The condensers at least are bigger in R134 systems then R12 ones.