A/C works great, for around 1 to 2 hours.

[Raffy]

Hi everyone.

A while back I took my car to an aircon place to have the A/C diagnosed. They ended up replacing the compressor which they said was leaking.

Ever since then, the A/C works fine, but after around 1 to 2 hours of continuous driving, the airflow drops off and gets hotter.

Ive been turning the A/C off for a few minutes then back on, that seems to work ok.

I did take it back to the aircon place, all the bloke did was start the car, bung his hand on the A/C pipes coming out of the firewall and pronounce that "its working TOO well"!?

I suspect that the evaporator is clogged with dirt and fluff and is icing up.

Trouble is that its a bugger to get at and if I'm going to have a crack at it Id like to know what you guys think.

If its clogged I guess Ill do the "hole saw in the side of the box trick" to get at it.

Regards,
Raff

 

[brad_m_is]

I think the refrigerant flow control in the compressor might be stuck on 100% causing the evaporator to ice up stopping the air flow.

 

[ConstantVelocity]

Does sound like it's icing up. Ask what gas they used, if they used Hychill it gets a bit colder. Or the control valve in the compressor might be set a bit low (they're non-adjustable). I'd probably just live with it, dropping the evaporator below freezing cools the car faster on hot days and gives that nice icy blizzard feel...

 

[uniacidz]

Check out this thread

Can use hose, as water drains though drain hole underneath evap core out of vehicle.

https://forums.justcommodores.com.a...oning-evaporator-without-removing-dash.209935

 

[brad_m_is]

Does sound like it's icing up. Ask what gas they used, if they used Hychill it gets a bit colder. Or the control valve in the compressor might be set a bit low (they're non-adjustable). I'd probably just live with it, dropping the evaporator below freezing cools the car faster on hot days and gives that nice icy blizzard feel...

Hey firstly if he is on here asking for help I don't think he want to just live with it. Also what is this different gas you are talking about? the system is designed to run on 134a only. I don't know what u mean with the control valve and at no point is it normal for the Evap to freeze to so called cool the car faster????

 

[Raffy]

Thanks for the ideas guys.

I don't really want to live with it.

I have a Calais with ECC and Id assume that once set at a certain temp it would get to that temp and stay there.

I paid top dollar ($770) to have the A/C supposedly professionally diagnosed and repaired.

Im a disabled pensioner and that sort of cash is a fortune to me, but I just wanted it sorted.

Would the valve in the back of the compressor really be faulty or misadjusted? On a brand new compressor?

The mob I went to are well known and have been around here (Gold Coast) for ages, although they've changed their name a few times over the years. They do radiators and car A/C nothing else that Im aware of.

Just wondering if anyone else has had the problem and if cleaning the evap fixed it.

I wonder if I dropped the fan out and tried bunging the house in place of the fan would work?

Thanks,
Raff

 

[brad_m_is]

The reason I know this is because Im a refrigeration mechanic and I had this problem with my brand new compressor. Have you noticed if the compressor clutch is cutting in and and out?

 

[Raffy]

I haven't noticed the clutch cutting in and out, but then I haven't paid a huge amount of attention to it as the problem really only shows up mostly after at least 1 hours driving.

I might temporarily wire up an LED to the clutch wire and dangle it below the dash to see when the compressor clutch is on.

Im a retired electronics tech so that's easy for me to do.

I do know that they didn't use a genuine Delphi compressor, but one they said was "better" Ill have a look and read the label and post it in case its a dud.

 

[ConstantVelocity]

Hey firstly if he is on here asking for help I don't think he want to just live with it. Also what is this different gas you are talking about? the system is designed to run on 134a only. I don't know what u mean with the control valve and at no point is it normal for the Evap to freeze to so called cool the car faster????

This little guy is the control valve: NEW Control Valve FOR Compressors GM V5 | eBay

It controls the compressor stroke to maintain the suction pressure at 30 psi... there's a few different valves for different cars depending on the length of the suction line etc, if it's a non-genuine compressor it might be set a bit too low. At 30 psi it will maintain the evap temp just above freezing with r134a, the clutch should not cycle at all when the AC is on. But if they used hychill (basically refined LPG) it has a bit more pressure at low temps (lower boiling point) and will get a bit colder at a given suction pressure. Works well on short tips but will freeze up eventually.

Fair enough if you don't want to live with it, for the money you paid they should sort it for you. The variable displacement compressors make them a bit of a finicky setup.

 

[Raffy]

So if I was to put an LED on the clutch power line, and the clutch never cycles that would mean that it isn't that control valve at fault?

Its been quite a while since I got the new compressor fitted and I doubt Id get any sort of attention under warranty that's all.

I was even considering getting my own set of gauges to hook up and check the pressure myself as I'm really struggling to trust anyone who works on my car theses days, just search for my "pedders" experience.