[JeffdeVeer]

Temperature is about 95 here but that's no hotter than it's been all summer. Compressor runs as expected.

Coldest I'm getting at an AC vent w/ it running at full blast is 70. I have a simple gauge that goes on the low side and it's showing about 65 PSI while it's running which is supposedly "overcharged". My truck at the same ambient temperature blows 60 degrees.

The van is an '07 with 60k mi and as far as I know has never had freon added. I have had it since 28k and I definitely haven't added any. So, I doubt that it's truly overcharged.

I was out of ideas so I vented a little of the charge. This only had a temporary effect on the low side pressure and made the output temperature rise a few degrees higher permanently.

Would this likely be a compressor issue or some kind of clog in the refrigerant path? Any other ideas? I really hate having to turn my vehicles over to a mechanic.

I will be pretty unimpressed if the compressor is bad at this age/mileage. Would a compressor typically "fade" like this while still functioning enough to create 70 degree air?

Thanks,

Jeff

 

[JeffdeVeer]

BTW I noticed that this is supposed to have "Genuine Honda Synthetic PAG" so I assume it's a bad idea to add a freon/oil charge from a can at AutoZone or wherever. Would it be ok to add a little bit of straight freon to get it back to how it was before I vented some until I can get it working 100%?

Obviously 70 degrees is somewhat acceptable but it takes a really long time to cool down a 100+ degree car when all we're pumping out is 70+ degree air.

 

[0dyfamily]

Jeff, I know it's an '05 (mine are '02 and '03), but for discussion let's assume they use similar maintenance protocols.

Simply using a gauge on the low side isn't a very good diagnostic means, though it does yield some data.

You need to run the A/C with doors open, in a non-windy area (covered, like a carport is good) at 1,500 rpm until inlet temp is stabilized. That means using some sort of multi-channel digital thermometer (second channel for ambient temp, intake near blower unit under passenger dash).

You also need humidity readings. This enables you to get into the shop manual charts to determine what the delivery & intake pressure readings need to be for a given delivery temperature.

Don't just add freon until it "feels right". You may get good results in those conditions, but the wrong charge can give less than desired results under all the other conditions the system is expected to operate.

OF

 

[William Wiles]

AC in today vans are complicated systems. Messing with it the way you are will just create a disaster. Stop adding/removins coolant and take it to a shop that specializes in AC work and have it checked out properly. Make sure that the shop you take it to works on Honda's.

 

[JeffdeVeer]

Well, I did figure out that when running at like 35+ MPH it will blow 56-60 degrees. As soon as I let off the accelerator it rises 2-3 degrees and then slowly rises to 70 degrees when stopped. The fans are definitely working though. I tried misting water over the condenser while idling in the driveway and that didn't really help.

So, I figure it needs to be done anyway so I'm going to change the belt just in case it's slipping. It's at least 35k miles old, probably 60k. Does it sound logical at all that a worn belt could slip without squeaking and cause the compressor not to spin fast enough at idle?

BTW I added about 1/4 of a small can of straight R134a to bring it back up to 65 PSI like it was before I vented some.

 

[0dyfamily]

I don't want to bear bad news...nobody does, but if the belt slips that much, you'll smell it before you see a big loss in performance (i.e., burnning, or glazing the rubber surface of the mini-vees in the belt). I wish it were that simple, though.

Maybe you brought the low side up to 65 psi, but was it under identical stabilized inlet temp, outlet temp, and humidity conditions? If you don't know, then that number is only a ballpark guess at best. You're in the ballpark, it's working (somewhat), and that's all we can tell.

The misting water-on-the-condensor trick is useful for really only one thing...if you do it, and the suction pressure of the system drops, you've got too much refrigerant. It doesn't tell you anything else. If this were the case, you'd have to recover, evacuate, and recharge with the proper amount.

Best I can say is what WW said earlier: you should take it to an A/C specialist who knows how to work on Hondas.

OF