A/C not cold when hot @ idle... Tried Everything!

[bigjoncoop]

2007 Honda Odyssey EX-L
145K

Ever since I purchased this vehicle about 6 months ago I can not get the A/C to blow cold when it's hot outside while idling...

I Live in central Florida and as you can imagine it's SUPER hot this time of year. I do construction and sit in my vehicle during the lunch. I currently need to try and find some shade to park under to have any hopes on getting some cold A/C.

While driving or at night at Idle, the A/C blows super cold around 45° or lower.

But during the day parked in the sun @ idle the A/C is blowing at only 70° - 75°... If parked in the shade it blows slightly cooler but not much.

***** WHAT I'VE DONE SO FAR *****
Last week I had the system evacuated, and I connecting my vacuum pump and let it pump for a good hour. Then let the system sit for an hour to ensure I had no leaks. I then added exactly 725 grams of R-134a using a kitchen scale, and according to the my manifold gauges the pressures were spot on! (Service manual shows the vechile needs between 700g - 750g of R-134a)

I also confirmed that my electric fans are on while the system is calling for A/C. The only other thing I could think of was checking the condenser to make sure it wasn't clogged or the fins were all bent. But after thoroughly checking, the condenser coil looks great...

So I'm currently at a loss of what's going on. As I mentioned the A/C blows super cold while driving or at idle when the sun is down!

Does anyone have any ideas what could be goin on? I've also noticed that if I do not have the recirculating turned on AC blows substantially warmer all the time.

[event3horizon]

I just had this problem with my 2001 Benz S430. The only thing that helped was a new compressor. The compressor was 24 years old and 'tired' I guess they call it. Just didn't have the pumping/sucking efficiency any longer. I am in FL too (Sarasota). Post your low side and high side PSI @ 1500 or 2K rpm during a real hot day. The gentleman here usually request that first to give the best advice possible. It's also very difficult to charge by weight with 12 oz cans. You may think a full can is 12 ounces but sometimes that's not the case. I think you may also benefit from changing out your drier/accumulator if it's the original one.

[Tim]

It's hard to understand what's happening without the correct pressure readings being noted.

[JohnHere]

Do you have rear A/C in your Odyssey?

[bigjoncoop]

It's hard to understand what's happening without the correct pressure readings being noted.

I will post the after work. Last time I checked they were just about where they should be 45 on low and slightly low on the high side around 210 @ 85°. BUT I will throw the gauges on tonight and recheck.

Do you have rear A/C in your Odyssey?

Yes it has dual / rear climate control

I just had this problem with my 2001 Benz S430. The only thing that helped was a new compressor. The compressor was 24 years old and 'tired' I guess they call it. Just didn't have the pumping/sucking efficiency any longer. I am in FL too (Sarasota). Post your low side and high side PSI @ 1500 or 2K rpm during a real hot day. The gentleman here usually request that first to give the best advice possible. It's also very difficult to charge by weight with 12 oz cans. You may think a full can is 12 ounces but sometimes that's not the case. I think you may also benefit from changing out your drier/accumulator if it's the original one.

Yeah I used the little 12 oz cans but I did it by weight not by just adding the cans. I use the kitchen scale

[JohnHere]

The low side is high (depending on whether you have the rear A/C turned on or off), but the high side is just about where it should be. See what you get later, recording pressures with the rear A/C turned on, then turned off.

The data that I have show a different amount of refrigerant than you posted. I have 32 ounces net weight (907 grams) of R-134a for an '07 Odyssey with rear A/C. If my data are correct, then the system is undercharged by a considerable amount. For reference, you posted 700-750 grams, or 25-26 ounces net weight.

Check to see whether you have an under-hood decal printed with the A/C specs. If so, the decal takes precedence over all other data.

Lastly, a system that holds vacuum doesn't necessarily mean that it won't leak under pressure, especially on the high side. So a vacuum test is only 50-percent of the leak testing procedure.

[tbirdtbird]

We need the standard info:
At 1800 rpm, give the hi, low, ambient, center dash vent temp with windows open, for a full load test.
A comp does very little work at idle, which is why the AC blows warmer at a stoplight. It is unrealistic to think it can be better.