Automotive Air Conditioning Information Forum (Archives)

Metal Man on Wed June 10, 2015 7:56 PM

Year: 1998
Make: honda
Model: civic
Engine Size: 1.6
Refrigerant Type: 134a
Ambient Temp: 87
Pressure Low: 60
Pressure High: 115
Country of Origin: United States

Just bought a 98 civic. Ac works intermittently. I recovered the 134a and system was over charged by 4oz. I vacuumed and added correct charge. Now at idle low side pressures are in the 50 to 60 range. High side in the 100 to 120 range. At 2000 rpm compressor starts doing as it should. Low side falls in the 30 range and high side raises in the 200+ range. A little more throttle. And low side falls till the low pressure switch starts cycling the compressor. Return to idle and the low side pressures are back in the 50 to 60 range.

Of course the air is only mildy cool at idle at best and it also alternates between hot and cold with driving. I've only had my gauges hooked up while setting still. Have not hooked them up for a test drive.

Scratching my head on this one. Not sure if it's a tired compressor or the expansion valve. HELP!

Jerry.


Edited: Wed June 10, 2015 at 7:58 PM by Metal Man

HECAT on Wed June 10, 2015 8:22 PM

Used cars come with mystery history, someone's been doing something if it was overcharged. It could (highly possible) be a leaker and may have been recharged with cans containing oil and the who knows what it is sealer stuff. Oil overcharge will increase the amount of oil coating on the inside of the heat exchangers (insulate), cause higher than normal low side pressure, poor heat rejection, and poor cooling at idle; (also fans, air flow, etc.). For me, this one (as a new member of my fleet) would need a lot of unknowns resolved (no more "not sure" scratching of head). I would get a compressor, filter, and expansion valve. Flush everything else clean and DRY; then fresh load of oil, vacuum, and recharge.

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Metal Man on Wed June 10, 2015 8:35 PM

May be the best thing, removing the unknowns.

Don't much mind replacing the big parts but I sure do hate having to replace TEV'S.

mk378 on Wed June 10, 2015 11:14 PM

Doesn't work at idle, works a little better at higher rpm is very typical of a worn out scroll compressor.

TXV is replaced by removing the entire evaporator box from the car first, the disassemble it on the bench. Access is by taking the glove compartment out (unscrew the hinges at the bottom), there is no need to remove the whole dash.

There is no low pressure switch. Compressor will cycle off on evaporator temperature (normal) or excessive high side pressure (abnormal).

bohica2xo on Thu June 11, 2015 7:47 PM

Dying scroll compressor. It is shedding pieces now.

Compressor, condensor, dryer. Usually that gets all of the debris. I would still pull the TXV & check it's inlet for junk.

Replacing most of the high side components & the compressor, then flushing the remaining parts back to bare metal gives you a new system - no guesses about oil quantity or quality already there...

B

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"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.

Metal Man on Thu June 11, 2015 7:53 PM

Thanks mk378. I had a little time to look it over today. Definitely needs a compressor. Clutch gap is fine but after the the compressor cycles a few times the electro magnet becomes to weak to keep the clutch engaged.Weak clutch and low pressures means I'll be replacing it tomorrow.

Thanks

Metal Man on Thu June 11, 2015 7:55 PM

Thanks bohica2xo. That's my next move.

Metal Man on Fri June 12, 2015 8:21 PM

Ok, took me most of the day but I got it. Pulled the compressor and lines. Like most here have said, the scroll compressor had started self destructing. So I added a new compressor, TXV,condenser and dryer. Removed all lines and flushed them along with the evaporator core. Added all new orings and schrader valves. Added 5 oz of pag 46. Gonna leave it under vacuum all night and charge it tomorrow.

Anything im missing that I need to do before I recharge?

bohica2xo on Sat June 13, 2015 3:12 PM

Looks like you got it all - good job.

.

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"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.

Metal Man on Thu June 18, 2015 8:37 PM

Just wanted to post an update. Charged up the civic and ac is working as it should. Thanks for the advise guys.