Automotive Air Conditioning Information Forum (Archives)

SlickRidez on Thu June 25, 2015 6:09 PM

Year: 2004
Make: Honda
Model: Accord EX
Engine Size: 2.4
Refrigerant Type: r134a
Ambient Temp: 90
Pressure Low: 30
Pressure High: 135@2000
Country of Origin: United States

Thank you for reading my post!

I'm working on my Sister's 2004 Accord. The original complaint was insufficient cooling with an operational compressor and clutch engaged. A few months ago she said her A/C was blowing warm then the next week said it was working fine and apparently continued to do so until today.

Cooling fan is operational and condenser is clear without any bugs or debris.

I added 12oz Freon to the system carefully without evacuating (mistake). At first all appeared well. The system pressures were normal and cooling was initially excellent. About 10 minutes later I took the RPM to 2000, checked pressures (30 low and 250 high) and let off the throttle. Shortly after returning to idle the high pressure spiked to 450 disabling the clutch. Once the pressures dropped (slightly, to about 375) the clutch engaged again and the pressure spiked 450. I tried hitting the condenser with water from the garden hose during these high pressures and the high side failed to drop. After shutting the car off and letting it sit for a time I re-started and fired up the A/C. After about 10 minutes the pressure spikes returned after return to idle and furthermore the pop-off on the compressor activated The problem repeated itself until the pressure spiked again, straight to 500psi resulting in my shutting everything down.

I discharged the system thinking moisture and air might be present (plus I probably overcharged it by just adding Freon). As I was evacuating the system had just started to go in to vacuum, then I heard a "POP" and noticed the low side gage went back up to about +10psi. After this I continued to evacuate the system succesfully with no further noticeable issues. After verifying no leaks I re-charged the system. Upon installation of 12oz Freon I started the engine and activated the A/C. Initially the low side was in a vacuum and the high side was about 80. I considered the possibility the expansion valve was stuck (due to the low side in vacuum) but the system continued to accept Freon. After reaching system capacity the pressures were 125 high and 30 low @2000rpm @90 ambient and 55% rh. At this time cooling was only marginal. BTW system capacity is 19.2 max. I know I have at least 22oz in there (oops....didn't close the low side valve fully).

Now with the system slightly overcharged the cooling is excellent at 2000rpm and very good at idle with about a 5 degree temperature increase. Here's the problem: The high side reading never goes above 125-130 PSI regardless of RPM and the gauge readings take FOREVER to equalize after shut-down! In fact after shut-down of the engine the high side pressure rises to about 150 then slowly (and I mean slowly) starts to come down. I waited 10 minutes after shut down and re-checked the gauge readings, they were 90 low and 125 high. I just went out there after 15 minutes and the readings are 85 low and 115 high. I just went back out there again (now 30 min after shut down). The low is 99 and high is 110

Something feels not right here.....the pressures should equalize pretty fast....but does not. The initial "in vacuum" low side reading after evacuating and re-charge hints towards the expansion valve being stuck but at the same time I saw signs here there may be a high side restriction as well, like maybe a failed R/D desiccant bag?

Although cooling is excellent at RPM when I touch the low side line by the service ports the line feels warmer than the air coming out of the vents. When I touch the high side line by the service ports it is not at all hot like I would expect it to be. On the other hand when I touch the high side line by the compressor it is hot hot, like I would expect.

So does anyone have any ideas what may be going on here? I just don't want to give the car back to my Sister not fixed properly and her aging dog (riding buddy) just can't take no A/C. I'd hate for them to get out and about, the air quit on them and something bad happen to the dog (and my Sister too).

I appreciate any help you may be able to give!


Edited: Mon July 13, 2015 at 10:16 PM by SlickRidez

SlickRidez on Thu June 25, 2015 8:39 PM

Quick update: Running @ 2000rpm: High side 120 low side 20-25 and cools like a beast....I mean crispy!

Also I failed to mention the high side reading doesn't vary much.....maybe 5-20psi after going from idle to 2000rpm.

What the ph am I missing here....... I would initially say there's not much cooling taking place with those readings.

If it were 500psi high all the time I'd say BINGO and find the restriction in the high side probably somewhere around the R/D or condenser.....but no pressure variance and low high side readings (presumably....as I'm now questioning everything I know at this point) just screams TXV stuck....perhaps in a position some cooling will take place but at it's position won't allow the high side to ramp up pressure? I'm thinking the problem has to be at or beyond the TXV. If it were stuck closed wouldn't high side readings be too high?

Thanks for any thoughts!

cross6 on Thu June 25, 2015 8:40 PM

Expansion valve. May be faulty. Or may be full of metal from compressor starting to frag.

SlickRidez on Thu June 25, 2015 8:42 PM

Yeah and that comp. was sounding a bit noisy when it arrived. After vac and charge I installed oil slowly until it quieted down. What a bummer if this compressor claps out at only 81K!

bohica2xo on Fri June 26, 2015 2:51 AM

You have a faulty high side coupler.

It pressurizes the hose with static pressure when you snap it on because of the over travel. When you let go, the schrader valve closes.

That is why your high side never moves. You really have no reading on high side pressure.



-------------------------
"Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest."
~ Mahatma Gandhi, Gandhi, An Autobiography, M. K. Gandhi, page 446.

Cussboy on Fri June 26, 2015 8:54 AM

Quote
Originally posted by: bohica2xo
You have a faulty high side coupler.

It pressurizes the hose with static pressure when you snap it on because of the over travel. When you let go, the schrader valve closes.

That is why your high side never moves. You really have no reading on high side pressure.


Bohica is saying that you should try to press down hard on that high side coupler while the engine and AC are running (be safe), to take a pressure reading. I had to do the same with my gauge set on my 1994 Suburban, just was a little too deep for the coupler to actuate by itself. Same gauge coupler worked fine on other vehicles.

SlickRidez on Fri June 26, 2015 12:04 PM

Thank you for the replies everyone!

I discharged the HS hose, re-attached it and pressure is present at the gauge

Edited: Fri June 26, 2015 at 12:05 PM by SlickRidez

mk378 on Fri June 26, 2015 2:55 PM

You're not going to have much if any cooling with the high side being only 130 on a 90 degree day. The point was that the reading is almost certainly wrong.

SlickRidez on Fri June 26, 2015 3:44 PM

I have to agree....I took the car back to my Sister yesterday, turned AC on high and recirc. By the time I got there the rear and side glasses had dew on them. I left it run for my Sister to check it out and by that time all the glass and even the roof had dew on it. The compressor is whisper quiet and the system cycles.

I'm wondering if that pressure spike took out my high side gauge? The manifold set is old.....and a cheapee Harbor Freight special. I'm not knocking it tho it lasted 7 years and did a great job!

SlickRidez on Fri June 26, 2015 7:48 PM

Well thanks to all who replied and looked at my thread. I appreciate everyone's time and thoughts. For now it's cooling and working great so I'm going to leave it at that with my appreciation for you all!

SlickRidez on Mon July 13, 2015 10:14 PM

Update: My neighbor's A/C stopped working in his Blazer. I fixed the leaks, vac'ed and re-charged.

Interestingly enough the high side pressure registered 190 or so on my H/S gage......completely appropriate for atmospheric conditions present at work time.....and she blows ice cold.

Looks like my blown H/S gage theory just straight got pimped off!

I still can't see the Honda making cold air with 120 high?????

Welcome to the twilight zone....I guess!!