Automotive Air Conditioning Information Forum (Archives)

timothy1959 on Sat June 13, 2015 10:42 PM

Year: 1999
Make: Honda
Model: Civic LX
Engine Size: 1.6 L
Refrigerant Type: R134a
Ambient Temp: 100 F
Pressure Low: 30
Pressure High: 185
Country of Origin: United States

I recently bought an (unmolested) 16 year old Honda Civic that needed a head gasket. The previous owner told me he replaced the A/C compressor during his 10 years of ownership (since 2005). I replaced the head gasket. The engine now runs GREAT but the A/C center vent temp is VERY high (94 degrees F). The A/C static pressures are LOW: 166 psi and HIGH: 125 psi. I am not sure where to go from here. Any suggestions would be great. TIA! :-) Tim


Edited: Sat June 13, 2015 at 11:01 PM by timothy1959

Jag987 on Sun June 14, 2015 12:25 AM

carefully touch the low side line right where it come back through the firewall and I to the engine compartment. It should be cold. If it is, my first guess would be the heater valve is not shutting off the flow to the heater core causing the cooled air to get reheated. Maybe a blend door not operating properly. Having just done engine work, I would look hard at the heater valve and lines.

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I bought a can of 134a at w**-mart that had a stop leak, oil, and dye in it. It also had a hose and a gauge, so now I'm an AC pro!

mk378 on Sun June 14, 2015 12:46 AM

The heater valve tends to get out of adjustment. You probably need to move the cable housing where it attaches to the valve to be sure it pushes the valve fully closed when the dash lever is on full cold.

bohica2xo on Sun June 14, 2015 8:19 PM

Scroll compressor.

You can't get much of a test at idle. Spin the engine rpm up to 2,000 to 2,500 & record the pressures. Cabin fan on highest speed, doors open.

Post your results & we can go from there.

.

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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.

timothy1959 on Mon June 15, 2015 3:04 AM

I tested the pressures again tonight, results = Engine RPM: 2,000, Low Side Pressure: 24 psi, High Side Pressure: 340 psi, Center vent temp: 68 deg. F, Ambient temp: 94 deg. F. TIA! :-)

timothy1959 on Mon June 15, 2015 3:05 AM

Quote
Originally posted by: bohica2xo
Scroll compressor.

You can't get much of a test at idle. Spin the engine rpm up to 2,000 to 2,500 & record the pressures. Cabin fan on highest speed, doors open.

Post your results & we can go from there.

.

I tested the pressures again tonight, results = Engine RPM: 2,000, Low Side Pressure: 24 psi, High Side Pressure: 340 psi, Center vent temp: 68 deg. F, Ambient temp: 94 deg. F. TIA! :-)

timothy1959 on Mon June 15, 2015 11:51 PM

Quote
Originally posted by: bohica2xo
Scroll compressor.

You can't get much of a test at idle. Spin the engine rpm up to 2,000 to 2,500 & record the pressures. Cabin fan on highest speed, doors open.

Post your results & we can go from there.

.
Some additional info: With the A/C on FULL BLAST, the center vent temp drops down to about 52 degrees F if I drive the car at highway speed for about 15 mins.
As soon as I stop the car, the vent temp then slowly rises to about 93 degrees F, with an ambient temp of 100 degrees F.
If that helps anyone.


Edited: Mon June 15, 2015 at 11:54 PM by timothy1959

mk378 on Tue June 16, 2015 8:27 AM

Go back to what Jag said about the pipe getting cold. The air should be at least as cold as the suction line is.

Cussboy on Tue June 16, 2015 9:35 AM

Are all your engine/condenser fans running?

timothy1959 on Tue June 16, 2015 11:27 AM

Quote
Originally posted by: Cussboy
Are all your engine/condenser fans running?

Yes, both fans work the way they should.

timothy1959 on Tue June 16, 2015 11:29 AM

Quote
Originally posted by: mk378
Go back to what Jag said about the pipe getting cold. The air should be at least as cold as the suction line is.

The center vent temp & the suction line seem to be about the same temp.

bohica2xo on Thu June 18, 2015 1:59 AM

A condensor issue is most likely, or a bunch of air in the system. 340 psi with a 100f ambient is not good at all.

The condensor air side could be blocked wit bugs/grease/dirt/paint... or the previous compressor could have filled the refrigerant passages with debris as it failed.

I would be inclined to recover the system & replace the condensor, dryer & TXV, along with a good flush on the lines & evaporator.

-------------------------
"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.