SEAT Alhambra (1996 - 2009) - 02 1.9 AirCon stops on long runs.

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Sat 13 Jun 2009 17:47
02 1.9 AirCon stops on long runs. - fredthefifth
Hi All,

Anyone got any ideas on this? Its on an Alhambra 1.9 TDi (115 bhp) SE with climate control.

Few months ago i noticed that although around town the aircon works fine, at some point on a long run (ie 90 miles) it stops working.

So as a starting point decided to have the aircon serviced as it was due - about 3 years. Anyway no problems reported. Garage looked at the diagnostics too and no faults found. No loss of pressure or anything and I do trust the garage that does this for me.

After the service I tested again and around town, on lowest setting and with the fan speed at about 30% the vent temp drops to about 2C with the ambient at 26C (this was the hot weather a couple of weeks ago). So i was dead chuffed. That'll sort it I thought!

Did the long run again today and as before on getting there with the same test as above the vent temp only drops to about 10C with the ambient at about 21C!

Get home, engine cools test again and all is fine again!!!

Any ideas?

Cheers.
FTF
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Sat 13 Jun 2009 18:03
02 1.9 AirCon stops on long runs. - injection doc
check to make sure the cooling fans are running when the AC is on.
When these systems are charged is it imperative to make sure that they are half charged & then started & run to disperse the gas & then the rest of the charge to follow. If they are charged in one hit the liquid gas floods the pump & causes hydraulic damage.
The most common problem is pump failure which causes lots of tiny fragments to travel up the system & block the control valve. If you can't get the fault diagnosed easily then have the system de-gassed & remove the AC pipes from the compressor to the control valve & wash through the pipes with cleaning fluid through them onto a rag. Allow the rag to dry & see if it sparkels in the sun. If it does the pump is failing & the control valve will be blocking up. It normally spells disaster for these vehicles as you can never flush all the swarf out the system so it keeps self destructing.
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Sat 13 Jun 2009 23:24
02 1.9 AirCon stops on long runs. - fredthefifth
Hi Doc, thanks for the reply.

Would that diagnosis explain why its ok around town but only stops working on longer runs?

Regards.
FTF.
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Sun 14 Jun 2009 09:45
02 1.9 AirCon stops on long runs. - injection doc
unfortunatley quite possible, have it checked out by a competent AC engineer. Once gauges are put on the system I think you will find its a pump problem causing swarf to block the control valve as it runs. Once the system stops & the pressure balances the swarf runs back from the control valve.
I hope there is a simpler explanation but I used to service the AC on a fleet of these & this was the most common issue. With the Galaxy the Ford equivalent you will find the ford dealer will only replace the whole AC system due to this particular common fault. used to cost approx £2800 at Ford
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