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Omega Help Area => Omega General Help => Topic started by: Jay w on 11 May 2008, 16:38:41

Title: Yet another Aircon puzzler
Post by: Jay w on 11 May 2008, 16:38:41
We didn't regas the aircon when we put the engine is as we ran out of time, this weekend we did it, did a leak test with another gas first (not sure what it was but it wasn't r134a) all held good.
Gassed it and it was nice and cold in the car. got in it today it there is no cool air at all.
Next door has one of the cheapy refill kits, we pulgged that on and it confirmed that the system has pressure (i didn't the kit just wanted to check that we had gas on the low pressure side)
We can hear the compressor clutch kicking in, the rev rise and fall when the aircon is switched and off.
have checked the high pressure side as well and there is gas in there, none of the pipes are cold.

any ideas?

Title: Re: Yet another Aircon puzzler
Post by: Entwood on 11 May 2008, 16:53:20
It's possible the expansion valve is stuck ... I believe the check for this is the pipe temperature either side of the valve, one side should be coldish - the other side should be damned cold !!!

There is a table somewhere .. I found it once but can't now ... that gives the high presure readings that a serviceable system should give ... it involved running the system at max lo for 30 minutes and was based on ambient temperature IIRC
Title: Re: Yet another Aircon puzzler
Post by: sassanach on 11 May 2008, 17:25:27
you need to read the ac pressures approx 40 psi low side 150-200 high side depending on ambient.a halfrauds filler kit will tell you jack sh*t other than you have gas in the system
Title: Re: Yet another Aircon puzzler
Post by: sassanach on 11 May 2008, 17:26:51
if the expansion valve is stuck you will have a vacumn on the low side :'(
Title: Re: Yet another Aircon puzzler
Post by: Jay w on 11 May 2008, 17:42:47
Quote
It's possible the expansion valve is stuck ... I believe the check for this is the pipe temperature either side of the valve, one side should be coldish - the other side should be damned cold !!!

There is a table somewhere .. I found it once but can't now ... that gives the high presure readings that a serviceable system should give ... it involved running the system at max lo for 30 minutes and was based on ambient temperature IIRC

no, both of mine were hot

The low pressure was reading 45psi, couldn't do the high pressure side
Title: Re: Yet another Aircon puzzler
Post by: sassanach on 11 May 2008, 18:36:15
when you took this pressure reading was the engine running?
Title: Re: Yet another Aircon puzzler
Post by: Taxi_Driver on 11 May 2008, 19:53:26
There must be enough gas in the system otherwise the compressor wouldnt kick in.
Title: Re: Yet another Aircon puzzler
Post by: Jay w on 11 May 2008, 19:59:18
Quote
when you took this pressure reading was the engine running?

Yes and the aircon was on Lo
Title: Re: Yet another Aircon puzzler
Post by: Marks DTM Calib on 11 May 2008, 20:03:22
Whats the vent temp?

What are the aircon lines doing, the high pressure feed to the condenser should be warm/hot and the return pipe just before the pulse damper should be cold.
Title: Re: Yet another Aircon puzzler
Post by: Jay w on 11 May 2008, 20:12:23
Quote
Whats the vent temp?

What are the aircon lines doing, the high pressure feed to the condenser should be warm/hot and the return pipe just before the pulse damper should be cold.

I haven't got a temp probe but i would say they are only just cooler than ambient.

Both aircon pipes are hot to the touch, now from experience the one with the low pressure valve on it should have condensation on it, this one doesn't  :(
Title: Re: Yet another Aircon puzzler
Post by: sassanach on 11 May 2008, 20:24:04
bit of a reach here without your high side pressure,but here goes, you have lost  a large amount of your refridgerant.
Title: Re: Yet another Aircon puzzler
Post by: sassanach on 11 May 2008, 20:27:16
what equipment did you use to do the regas?
Title: Re: Yet another Aircon puzzler
Post by: Marks DTM Calib on 11 May 2008, 21:03:15
I take it they re-fitted the primary seal dust caps!
Title: Re: Yet another Aircon puzzler
Post by: Jay w on 11 May 2008, 21:46:36
Quote
what equipment did you use to do the regas?

i don't know in all honesty, it didn't look that advanced.

In order to put the gas in they had to connect a bottle of R134a and put it on an electronic scales, 950 grammes went in as per the label on the slam panel
Quote
I take it they re-fitted the primary seal dust caps!

Err.....and they are what?  :-[

If you mean the little caps on the filler valves, yes



Title: Re: Yet another Aircon puzzler
Post by: sassanach on 11 May 2008, 21:59:31
so they came along and hung a set of pressure gauges from the bonnet, connected up a vacumn pump, vacced the system for a half hour approx and then sucked in 950 grammes of refridgerant from a bottle on a set of scales.sounds normal, using those guages any anomalies would show up,so im sticking with my reach as stated earlier
Title: Re: Yet another Aircon puzzler
Post by: Jay w on 12 May 2008, 07:37:55
Quote
so they came along and hung a set of pressure gauges from the bonnet, connected up a vacumn pump, vacced the system for a half hour approx and then sucked in 950 grammes of refridgerant from a bottle on a set of scales.sounds normal, using those guages any anomalies would show up,so im sticking with my reach as stated earlier

No.

The system was Vac'd for about 30 mins then a gas pumped in to check for leaks, that was then vac'd and then the R134A was put in
The guages that were used in the garage were part of a rig, they were on the unit that was being used to Vac.

the only way i could describe this unti was ir was about 2 foot long, stood 3 foot hight, had a compressor type unit on it, control panel with knobs and guages and the high and low pressure lines.

not much help i know  :(
Title: Re: Yet another Aircon puzzler
Post by: Marks DTM Calib on 12 May 2008, 08:41:21
Did you cover all the pipe ends on the aircon system when you did the engine swap......hopefuly no debris got into them.
Title: Re: Yet another Aircon puzzler
Post by: Jay w on 12 May 2008, 19:28:05
Quote
Did you cover all the pipe ends on the aircon system when you did the engine swap......hopefuly no debris got into them.

yep, we were very careful about that  :y
Title: Re: Yet another Aircon puzzler
Post by: sassanach on 12 May 2008, 22:09:06
you have described a charging station,my moneys still on low refrigerant level.any sign of leakage?
Title: Re: Yet another Aircon puzzler
Post by: Jay w on 13 May 2008, 12:41:41
Quote
you have described a charging station,my moneys still on low refrigerant level.any sign of leakage?

None that i could see, there was a green dye put in as well and we cant see any of that on the components.

The car was sat for most of the day as well so i woudl have expected to see it on the floor as well i would have thought


Title: Re: Yet another Aircon puzzler
Post by: colalowe on 13 May 2008, 14:21:59
Probably a daft question but have you tryed the reset, holding the Auto and Off buttons in for 10s??

Every so often mine stays warm or not as cold as you would expect, it just needs resetting and its fine again.
 :y
Title: Re: Yet another Aircon puzzler
Post by: sassanach on 13 May 2008, 22:46:16
favourite places for a leak are compressor seal,underside of compressor,and the old  favourite the condenser.usually on the underside