Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Mike Collins on 09 May 2008, 19:25:00

Title: Air conditioning problem
Post by: Mike Collins on 09 May 2008, 19:25:00
A question for the a/c experts amongst us.

My 2.6 has a slow, but increasing, refridgerent leak, the last fill was around four weeks ago and it's already on its last gasp.

No leak shows when the system is vacuumed out and it will hold a steady pressure with nitrogen. I have looked around with a small UV torch and goggles without finding any trace.

Today I removed all the front panelling to inspect the condensor, there was plenty of rubbish in the far corners of the fan shrouds but no obvious corrosion.

I have applied soapy water in the hope of seeing bubbles, none seen.

It's a 2003 2.6 and as it's done around 135,000 miles, I'm tempted to change the condesnsor anyway.

Any thoughts?
Title: Re: Air conditioning problem
Post by: sassanach on 09 May 2008, 19:51:06
take a shufti at the underside of the compressor!!.
Title: Re: Air conditioning problem
Post by: Mike Collins on 09 May 2008, 23:16:54
I don't like the sound of that, am I looking for shaft seal leakage or a leaking connection?

There is no sign of PAG oil being thrown from the front seal.
Title: Re: Air conditioning problem
Post by: BigCat on 10 May 2008, 01:45:56
I had a similar problem with my 2003 model 3.2, which took quite some time to lose all the gas.

It turned out to be one of the rigid tubes that had been damaged by rubbing against the chassis/bodywork.

Unfortunately, I didn't ascertain from the mechanic exactly which one it is, but I do know he had to remove the battery among other things to get to it.
Title: Re: Air conditioning problem
Post by: Mike Collins on 10 May 2008, 14:57:43
I've now had a good look at the underside of the compressor, there is a very slight oily stain at the front. It does not react to my UV torch and I can see no leakage around the pipes.

Shaft seal leakage? I believe it's replaceable on the later cars.
Title: Re: Air conditioning problem
Post by: The Barge Captain on 10 May 2008, 15:34:07
I belive they are prone to leaking where the solid pipe passes from the engine bay through the bulkhead.
Title: Re: Air conditioning problem
Post by: sassanach on 10 May 2008, 17:48:35
they also leak at the o rings that join the two halves of the compressor together, had a few like that usually they leave a tell tale oil stain on the underside, BUT not always.
Title: Re: Air conditioning problem
Post by: Entwood on 10 May 2008, 17:49:25
I might well be wrong .. probably am .....  :(

but if the leak is from the gaseous side the UV trace won't show ?? I believe that only shows on "liquid" leaks. I would therefore concentrate and search using "bubble solutions" on the area between the expansion valve (side of evaporator) and the inlet of the compressor, I'd guess at evaporator problems before condensor.

????

HTH
Title: Re: Air conditioning problem
Post by: Mike Collins on 10 May 2008, 20:26:16
Having just replaced the heater matrix in my wife's 2.5, the prospect of evaporator failure in mine does not fill me with joy.

I was wondering about the chances of finding a slow  leak with the dye trace. Presumably the molecular size of the dye is much larger than the gas.

My hope was that because the condensor is subjected to enough rubbish to case corrosion, that would be the easy answer.
Title: Re: Air conditioning problem
Post by: Taxi_Driver on 10 May 2008, 23:04:08
Quote
A question for the a/c experts amongst us.

My 2.6 has a slow, but increasing, refridgerent leak, the last fill was around four weeks ago and it's already on its last gasp.

No leak shows when the system is vacuumed out and it will hold a steady pressure with nitrogen. I have looked around with a small UV torch and goggles without finding any trace.

Today I removed all the front panelling to inspect the condensor, there was plenty of rubbish in the far corners of the fan shrouds but no obvious corrosion.

I have applied soapy water in the hope of seeing bubbles, none seen.

It's a 2003 2.6 and as it's done around 135,000 miles, I'm tempted to change the condesnsor anyway.

Any thoughts?

You will only see a leak if UV dye has been added on refilling.......and then only if you check quickly after leak.......coz spray from rain will wash it away........mine sprang a leak on an alloy pipe attached to the the condensor.........so needed a new condensor  :'(
Title: Re: Air conditioning problem
Post by: Taxi_Driver on 10 May 2008, 23:06:05
Quote
A question for the a/c experts amongst us.

My 2.6 has a slow, but increasing, refridgerent leak, the last fill was around four weeks ago and it's already on its last gasp.

No leak shows when the system is vacuumed out and it will hold a steady pressure with nitrogen. I have looked around with a small UV torch and goggles without finding any trace.

Today I removed all the front panelling to inspect the condensor, there was plenty of rubbish in the far corners of the fan shrouds but no obvious corrosion.

I have applied soapy water in the hope of seeing bubbles, none seen.

It's a 2003 2.6 and as it's done around 135,000 miles, I'm tempted to change the condesnsor anyway.

Any thoughts?

Shouldnt be leaking then.........what are the symptoms??
Title: Re: Air conditioning problem
Post by: Mike Collins on 11 May 2008, 09:01:30
It's taken around five weeks after the last test and refill for the a/c to lose  a lot of its cooling ability. Before that it was two to three months.

It was vacuumed and held, pressure tested and held. Refilled and worked for five weeks or so.

The compressor still runs but the pipe running across the top of the engine bay is no longer really cold.

Before the last session the pressure had dropped to the point the compressor would no longer run.

I did find evidence of chafing on the top pipe from the condensor where it was touching the transmission cooler bracket, unfortunately no leak shows at this point.

According to Vauxhall, dye is in the receiver/dryer from new.

Title: Re: Air conditioning problem
Post by: sassanach on 11 May 2008, 12:22:16
if you really can not see any leaks then triple or even quadruple the uv dye dose.the dye goes into solution with the gas, so if the gas is leaking then the dye is leaking.then when it all leaks out ,if you cannot see any  obviously visible leaks then it has to be somewhere behind the dashboard, ie expansion valve etc.also check for dye at the water outlets under the evaporater.shine your uv light over both sides of the gearbox next to the bellhousing.its got to be going somewhere!!
Title: Re: Air conditioning problem
Post by: Marks DTM Calib on 11 May 2008, 13:22:16
I assume that you have both the high side and low side caps fitted to the fill/monitor points?
Title: Re: Air conditioning problem
Post by: Mike Collins on 11 May 2008, 18:31:38
Yes, both caps fitted.

Title: Re: Air conditioning problem
Post by: Taxi_Driver on 11 May 2008, 20:08:13
Quote
It's taken around five weeks after the last test and refill for the a/c to lose  a lot of its cooling ability. Before that it was two to three months.

It was vacuumed and held, pressure tested and held. Refilled and worked for five weeks or so.

The compressor still runs but the pipe running across the top of the engine bay is no longer really cold.

Before the last session the pressure had dropped to the point the compressor would no longer run.

I did find evidence of chafing on the top pipe from the condensor where it was touching the transmission cooler bracket, unfortunately no leak shows at this point.

According to Vauxhall, dye is in the receiver/dryer from new.



Not sure i understand that......if its been refilled and no dye added then it wont have any dye in the system.....the dye only stays in the system if it doesnt leak....so if its leaked before then the dye has gone as well........was dye added on the last refill?
Title: Re: Air conditioning problem
Post by: sassanach on 11 May 2008, 20:30:37
that is one h*ll of a good point, i await the answer with intrest. :)
Title: Re: Air conditioning problem
Post by: VXL V6 on 11 May 2008, 20:33:45
I thought it was a requirement to have the dye injected after every recharge?



Title: Re: Air conditioning problem
Post by: sassanach on 11 May 2008, 20:44:50
not at all.usuallyonly if you suspect or have a problem.the oil i use has dye in it and i always add a little neat dye myself, but thats for my own peace of mind
Title: Re: Air conditioning problem
Post by: Mike Collins on 11 May 2008, 20:50:52
That I will have to ask about in the next day or so.
Title: Re: Air conditioning problem
Post by: VX1 on 11 May 2008, 21:56:03
So do the caps need to be put back on after a recharge then?
Title: Re: Air conditioning problem
Post by: sassanach on 11 May 2008, 22:04:46
most certainly they are the main seal of the valve
Title: Re: Air conditioning problem
Post by: VXL V6 on 11 May 2008, 22:07:17
Something to pickup everytime you visit a scrapyard  ::) No tools required and they fit in your pocket are only a few pence.
Title: Re: Air conditioning problem
Post by: VX1 on 11 May 2008, 22:12:25
Quote
most certainly they are the main seal of the valve

Oh dear, kwik fit forgot to put them back on. One was sitting on top of the battery cover and the other one is sitting on top of the scuttle, may be thats why it doesn'y feel so cold inside the cabin then. The gas may have leaked out since Friday. Looks like a trip back to KF to have it all checked.

Paul  :y
Title: Re: Air conditioning problem
Post by: Kevin Wood on 11 May 2008, 22:25:46
That reminds me. Kwik Fit stripped the thread on one of my valve caps so it doesn't tighten fully. >:(

Kevin
Title: Re: Air conditioning problem
Post by: HerefordElite on 11 May 2008, 23:53:03
Sorry to hijack this thread but i can't justify another "air con prob" when there are 4 on the go at once!!! ;D

i can borrow vac pump and gauges, and get R134a and scales to acurately re-charge but need to get the correct adaptors to fit onto the GM AC valves anyone know correct size?

what about these http://cgi.ebay.co.uk/AIR-CONDITIONING-BRAND-NEW-SET-OF-2-QUICK-COUPLERS_W0QQitemZ130221435479QQihZ003QQcategoryZ108798QQssPageNameZWDVWQQrdZ1QQcmdZViewItem?