AU2 Aircon problem

[cpab]

G’day AU guys and in particular any aircon techs,
I'm looking for some tips to track down a problem with my aircon, which I’ve had for near on 6 years now.
It just stops cooling seemingly, when it feels like it. On a mild day in the mid 20s it works terrific and freezes your balls off, but as soon as the temperature gets into the 30s, the compressor cuts out and it blows warm air. Sometimes the compressor comes back on when the engine revs drop to idle, but this is not always the case, it is very difficult to analyse why it is happening.
The first summer we had the car, I got a mobile aircon tech to check it out, he couldn't find a fault.
Following year; local Ford dealership serviced and regassed the system. A month later it was stopping cooling at various times.
Following year; regassed again with dye; no leaks found, but was still stopping cooling occasionally.
Following year had it checked thoroughly, the tech showed me some metal fines in a small gauze filter, but didn't specify any problem it could mean. He regassed again. This did nothing to improve the problem.
Had it checked again at xmas 2010 and tech said he wouldn't charge me because he couldn't find fault.
When I asked him for any codes from the diagnostic, he gave me P1463. From this I found Aircon Pressure Sensor Insufficient Pressure Change.

I’ve read quite a lot on various airconproblem posts and thought I’d solved it when a US aircon forum member advised me that my symptoms were classic clutch gap. My clutch gap was about .5mm to.6mm, so I filed down the washer in there(because you can’t get the damn shimwashers anywhere), so my gap is now about 0.2mm.(I found the gap should be 0.16mm to about 0.35mm). This seemed to cure it, but as the summer got warmer, the compressor started cutting out again. It was better, but has got progressively worse this summer. Now it hardly works at all, after early morning.
I’m considering taking a chance on replacing the pressure sensor/switch. I've also been reading that the receiver/dryer/accumulator ought to be replaced, which I will now also consider replacing.
Is there any other part I should address while my system is down?

Any advice will be gratefully received.


Here's hoping. Cheers
Chris

[pks54]

Hi cpab,
Cannot give you advice but I have the same thing happen to me. Hope someone chimes in and gives an answer as I too would like to solve this problem.

Problems seems to work about 80% of the time. I have found that if I pull over to the side of road turn off engine and start engine again it appears to magically work again. However it is hard to pinpoint exactly what the problem is.

BTW what model AU2 have you got?. Mines a 2001 AU2 200kw XR8 auto.

Will keep you posted if I get to the bottom of this problem.

[cpab]

G'day pks54,

2001 AU2 Futura 4.0L.
I remember trying stopping and starting again, xmas 2008 on a trip back from Karratha. Can't remember what strategies worked on that trip. Ways of getting it to work are not consistent, so I still don't have an answer, other than drive slowly on suburban roads. This seems the only way to keep it cooling some of the time. If we get on the freeway or open road, we just open the windows, cos it's not going to work at all.
I'll give the forums till next weekend, then I'll have to start spending money and time on it again. I may check any relays before degassing, though this may be another week or so, because I'll get the parts online.
I'll post again when I'm ready to make a move on it.

[cpab]

BTW pks54 your logo doesn't look like an AU.

[peterban]

I also have had this problem in the LTD.
I replaced the orifice tube and had it regassed by a friend.
My friend checked the pressures and told me the compressor was wearing it self out from the inside as the orifice tube had fine particles in it.
He said that the compressor could go for a few weeks or a few years.
It has been a couple of years and the LTD is now doing the same thing as you have described.
I have a new compressor, dryer and condensor to put in but don't have the tools to get the fittings off the dryer.
My friend doesn't have them as he retired years before the fittings became common.
He also recommends having the lines cleaned out before putting the new compressor on.

[mik]

a competent air con guy could flush the system for you, aside from the compressor problems if and when you think it is working as it should be refrigeration wise and if it`s still blowing the warm air on occasions, one other thing you can check is that the heater tap is closing off fully, ie it could be stuffed, or it could be a vacuum problem allowing the tap to go full hot under certain throttle conditions.

[cpab]

G'day peterban and mik,

Thanks for your information. Every little helps.

Yes peterban, in my case, I believe the filter in the orifice tube had thefilings from the compressor. The filter and orifice tube were replaced. Thetech did warn me that the fines were from the compressor, but he'd seen fineslike that in many systems that were working well. He did say that a newcompressor could be needed, but didn't have any definitive answers.

I would rather pay for the degas & regas and do the trial and errorfault finding myself, even if I don't know what I'm doing. I'll have to learnas I go. In 6 years I haven't come across an aircon tech who can tell me whatis the problem with mine, this includes 3 consecutive years with Forddealership. I'm not about to give any of them a blank check to keep going untilthey've replaced everything.

So, like you peterban, I’ll be looking to possibly replace the compressor,when I replace the dryer and pressure sensor. After adjusting the clutch gapand the compressor still packs in on hot days, I’ve considered the coil in theclutch may be inefficient or stuffed. So, a new compressor and clutch arelooking more certain to be part of my fix strategy.

As for special tools; I just hope Ican make something up to do the job.

Now mik, where’s this ‘ere heater tap? I did have a schematic of the AUaircon system, but it must be on my computer at work. I’d like to see what it’sabout and consider it.

Keep any ideas coming, I’ve got to change the window in our bathroom overthe next couple of days, so I won’t make any moves on the aircon till that’sfinished

Cheers

[mik]

the heater tap is under the inlet manifold on the six cylinders closer to the lower part of the engine from memory, sorry i have`nt taken much notice where they are on the 8`s if that`s what you have, defineatly worth checking for correct operation of the heater tap imo, if the tap is not closing you will NEVER have cold aircon, i`m 99% sure when there`s no vacuum the default position for the heater tap is fully open, good luck.

[cpab]

G'day mik
Thanks for that.
I haven't been able to qualify how the Heater Tap is controlled entirely. I've read alot and can see a possibility of some influence of heater over aircon cooling. The Ford handbook tells you to turn on aircon with heater for demisting, to dry the air.
Anyway, I've got to get on with other stuff, so $17-80 for Heater Tap/Valve on ebay is not going to break me, just the time to fit the bugger.
I'll do a bit more research on this one during the week.
Cheers mik and thanks again to all who have contributed.

Chris

[cpab]

Any contribution to this thread will really help. As I've said the problem has been in my car for 6 years and I don't want it being there for 7 years.
And I will post the solution, if or when I find and fix it.

[dink]

Originally Posted by cpab

Following year had it checked thoroughly, the tech showed me some metal fines in a small gauze filter, but didn't specify any problem it could mean. He regassed again. This did nothing to improve the problem.

i'll assume you meant metal filings. the following threads indicate your compressor is on the way out.

http://www.fordforums.com.au/showthr...mpressor+metal
http://www.fordforums.com.au/showthr...mpressor+metal
http://www.fordforums.com.au/showthr...mpressor+metal

i had the same problem as you did until i got my compressor, orifice tube and accumulator replaced.

[cpab]

Thanks for that dink. The orifice tube was replaced. I just want to check all possibilities before ordering a new compressor.
I have Wednesday free this week to try a few things. I'll post results.

[Nashie18]

How long does it take to remove an ac compressor from an Au2 6 cyl falcon fairmont 2002.

[Uncle_Ken]

Not that long but make sure there's no gas in the system