Have a 2006 RSX that has had AC issues since I purchased it. It would be cold, randomly get hot after a few mins, be cold, get hot after a few mins and do that over and over. I did not drive the car for a few months, tried the ac and it was hot. Checked the low and high side pressure, low side was at 350 (Maxed out on my gauge) and the high side was 150. The clutch was not coming on and it spun fine so I checked fuses and relays, all good. Decided to swap the pressure switch so I had the freon discharged, swapped the switch and had the freon charged again. First time trying the ac with gauges connected it was cold, low side was at 60-70 PSI though and the high side still at 150. I decided to turn the car off and the low side immediately jumped up to 350 on the low side.

I am pretty bad with AC issues so I am wondering if someone has came across this and knows exactly what to replace? Of course I was hoping to not have to throw random parts on it that don't need to be replaced. I figure I am looking at the expansion valve, drier, condenser or all 3? Thanks for all the help!

 

Sounds like the expansion valve should be replaced.

 

replace the drier too. every time you open a refrigeration circuit you need to replace the filter drier.

 

I am actually in the middle of swapping the expansion valve and drier right now. Got the crap under the dash all put back together and plan to fill the freon tomorrow. Hope this works!

 

Make sure to follow the factory charge to a tee. it's usually listed on a sticker under the hood but can also be found in the manual. Dont just fill it *****-nilly.

 

No go...it pulled a great vacuum and when I went to fill up the freon using a normal size 12oz can, the low side went up real fast. Compressor kicked on quick but the low side just climbed to 60 PSI. I didn't even put the rest of the 6oz it requires and it stayed at 60 PSI, high side at 250 PSI. The AC was cold and seemed to be doing good, but I turned off the AC and the low side just climbed slowly to 350 PSI (maxed out on the gauge). Seems like I got something else wrong...compressor possibly?

 

Is it actually 350 psi? can i see a photo of the gauge youre using? When you shut the AC off its normal for the low side to climb back up, but on some gauges after 120 psi the low side has a "retard" that goes to 350 but it doesn't actually have numbers so you don't truly know the pressure.

 

Hey OP can we get an update on this?

 

Yeah it went full retard lol Here is the gauges while the car was on with AC blasting, right after I put in one regular 12oz can of freon. This was after it was completely drained and I changed the parts out so it should have been able to take 6 more oz of freon. I shut the car off and the low side climbed all the way to 350 PSI where it says retard on the gauge...

 

Here is a pic before I did all the work this weekend...you can see it on full retard here

 

Could you take a guess at what the outdoor temperature was right near your truck when you shut the car off and took that second photo?

This doesn't necessarily look abnormal. when the system is shut off both sides of the system equalize. This means your high side is going to be your total system pressure, in this case 150psi. High and low are both 150psi in this case, the reason the low side doesn't show it is because it's an older R-22 gauge set and only goes up to 120. Anything after that is not actually a reading, its just a "runoff zone " for your gauge needle if that makes sense. Your low side is not 350psi.

Now this upper photo is concerning to me because it reads like a very large overcharge, but that combined with your lower photo leads me to believe you actually have air trapped in the system. Air is noncondensible so when you put air in a refrigeration circuit it essentially is shrinking the size of the system, making it look like an overcharge. Did you run a good vacuum and hold it for awhile to see if it leaked? 60 psi is way too high on the low end and 250 is way to high on the high side.

Pull good vacuum. Let the pump run for at least 20 minutes, the longer the better. Turn off pump, and let it hold for another ten or twenty minutes or so and recheck it. You need to carefully add the charge in through the yellow hose without introducing air into the system.

If you had those gauges connected to someone's house unit this is what I would be saying. Air in the system, air in the system, air in the system. Recover, vacuum, recharge.

 

If jermo is the same jermo from azht from years ago , our temperature was 114 high yesterday in az.

 

If that's the case then his pressures on the standing pressure test are just fine , it's just overcharged. On a 100-degree day I want you to have closer to 190-210 PSI on the high side , so if you have to let some out go ahead and do that and then report back to me

 

I mean bro 60/250 is just way too overcharged. 60psi on the evaporator is 62 degrees. We want that closer to 35 to 45 degrees

 

That's me!

Stin1 is correct, it was definitely over 100 degrees and 114 sounds about right. You say it's overcharged but I literally just had the freon pulled out, replaced the parts, vacuumed the lines for a good 15 mins (held at 30inHg) and then only put ONE bottle of 12oz freon in. How could it be overcharged with ONE 12oz bottle? This car requires 18oz so I imagined I would start seeing these kinds of numbers if I put TWO or more 12oz bottles in...if that makes sense.
Now I did notice the past couple times I filled it, the compressor immediately turned on as I put freon in and the low side crawled up quickly. Normally when I fill it, the low side climbs up to a certain point, the compressor kicks on and drops the low side down, then it begins to go back up and I try to shoot for 18oz which usually puts it about 40 PSI. The compressor kicking on right as I introduce freon is really bizarre...

 

Lets try this again. Going off the pressures alone its either an overcharge or air in the system. Try the standing pressure test, get a thermometer reading right next to your hood and read the system pressure with the car off. an 18 ounce system is really small, even small amounts of air in the system can screw things up. We can't really move much further from here until you do this step.

 

I am no ac expert but I think you should vacuum the system for at least 30-45 minutes. These cans you used do not have any leak seal do they? That stuff clogs up the system.

 

Correct and correct. Vacuum for at least 30 min. The Longer the better. Leak stop is fine to use in residential applications but car AC just doesnt have the power to handle that stuff. That being said, most cans of r134a DONT have leak stop in them.

Op needs to recover and pull a better vacuum and recharge. Air is noncondensible. It essentially is shrinking the size of your system, creating higher pressures.

 

Only thermo I could find was my meat thermo lol
Car has been off since last week and I haven't touched anything. Hooked up the gauges, car off and this is the outside temp. Right as I screwed down the low side hose I can hear it leaking, probably from the insanely high pressure...I don't think this tells us anything

 

This isnt "insanely high pressure". That looks normal. R134a is a low or medium pressure refrigerant. Somethinf like r410a is "high pressure". Used in residential and commercial applications it normally can run over 300psi on the high side depending on conditions. Carbon dioxide is even more high pressure.

That being said, your system looks fine but that test doesnt show an over or an undercharge condition. Now we need to have the sysyem running with good air flow over your condenser and radiator. The only thing i can suggest is emptying the system and pulling a 45 minute vacuum with a true micron gauge like we use in the field. Pull to at least below 1000 microns but pray for below 500. Refill tge system but MAKE SURE to bleed your hose you are charging from. Open refrigerant cylinder, and then loosen the yellow hose where it screws to your manifold and let the pressure escape for a couple seconds and then screw it back down. This is AFTER closing off both of your ***** on your manifold. If you dont know what youre doing just tell me and i can get it laid down step by step. Post up when you get a chance, we will be waitiing.

 

Thanks for all your help in trying to troubleshoot the issue here crazyhorse...I just replaced the AC compressor today and it's perfect now, guess that is what it was all along!