View Full Version : Car Air Conditioning issue RED HOT

22-07-2015, 08:57 PM

I was called to service a car (Vauxhall Astra 2001 plate) and done the usual vacuum, pressure test oil / leak dye, vacuum and then re-gas and have come to a problem.

Standard R134a system

Currently suction side shows 40 - 43 PSIg and discharge shows 160 PSIg at around 21 Deg c / 74F.

When the Condenser cooling fan switches off the discharge rises to about 200 PSIg (as condenser temp rises)

Thing is the air con simply does not get cold but seems to be chucking more heat out on the evaporator side.

Checked the usual baffle plate stuck and hot / cold valve and all is correct so its not blowing heat from the heater matrix though the evaporator.

Compressor kicks in but runs constantly, if switch turned off clutch plate is released so it not stuck permanently on.

Prior to gassing I rotated it manually (as it had not been used / ran for some time) and comp turned as normal not rock solid or sticking.

System had lost most of its charge, still had about 8PSIg in it, vacuum pulled and held ok, nitro pressure test ok so no leaks.

When the system is on the condenser and receiver get red hot and I mean hot the condenser cooling fan kicks in and cools it down a bit, the discharge pipe up to the evaporator is quite warm and the suction from it is also stays warm.

I am not sure what is going on here, anyone have an idea.

Compressor seems ok to me as readings are for the ambient temp correct (give or take the couple of odd psi)

Could this be a blockage / faulty TEX valve on / in evap ?


charlie patt
22-07-2015, 09:27 PM
Suction pressure to high also fan should not really cut in till 225 psi they get that warm they will bend a condensor like a banana .......is it a sub cooled condensor or drier on the side .is suction line sweating .also petrol or diesel .how much gas did u put in u probable got a bad pumping comp but your real issue with only eight psi in it the condensor will be leaking

22-07-2015, 09:50 PM

Thanks for reply, no sweating of suction line, drier is stuck to left side of condensor, I pressure tested it and no leaks actually left it for nearly 2 hours due to long phone call and plenty of time, needle not move at all so I don't believe its got a leak, believe it only has 8 psi in it due to lack of use as the owner said he never used the air con from new or had it serviced (due to not using it) until now as his wife is pregnant so is getting hot flushes or something while driving, gassed with 700 grams of R134a, car is petrol 1.6 Astra 2001

charlie patt
23-07-2015, 09:58 PM
They leak between condensor and radiator because they run high head they leak in about a month when u take condensor out u will sea corrosion anyway if u bring revs up u will probable get some cooling but basically comp poor pumping

13-08-2015, 07:51 PM
Failed slow fan speed, only high speed working.

Slow speed should run pretty much continuously, most even have a front and rear mounted fan unit. High speed only cuts in with there's a fault with the low speed.

Also check for expansion valve problems, galaxy (to 2005) suffer from oil collecting in evaporator and partially restricting the flow, this also produces high pressures and red hot condenser but slow speed still runs fine.

So check expansion valve is working fine and slow speed fan.

charlie patt
14-08-2015, 07:51 PM
With drier on the left side it does not have a sub cooled drier so fan is high speed or nothing on a 2001 Astra the 2001 with a sub cooled drier has low and high speed but will cool with only high working the two fans one is for ac one for engine cooling or wired for towbar or continental spec we are not the only ones to drive on the left apparently Astra fans usually run max 225 high speed cuts in all the time not where there is just a fault with a ambient over 14dc if u have a part restricted flow when u do your nitro test and u flow check it this will address if restriction