Kia Ceed air conditioning - help understand please

A hole in the condenser sometimes wont show for a while hopefully they used dye so they will be able to see where its leaking

There are any number of faults that could cause this. The control system for the aircon will likely measure the external air temperature, coolant pressure, cabin temperature, control settings, and the like; and will tell the compressor to operate. If any of the inputs are out of range the system may not operate. Or the compressor may not be working.

Some vehicles can report the aircon operating parameters via a diagnostic port - but the sort of local garage that re-gasses systems may well not have such diagnostics.

At 5 years old it may well not be economically repairable.

Really? Even if the compressor - maybe £200 for a reconditioned unit?

I had thought Kias had a 7 year warranty . . .

The warranty may be worthwhile but the fault may be called "fair wear and tear" so not covered.

But for a garage repair: fit new compressor, replace all flexible pipes and joins in the a/c system, replace heat exchangers, investigate cause of "wrong" inputs to control system (such as indicating external air temperature below zero when it is actually +25 or whatever), replace control module ... all that could add up.

Given that the diagnostic technique at most garages is to replace major components until the fault is cured rather than actually understand what is causing the problem, I can see that replacing the car may well be the cheaper option.

Would be interesting to hear what Kia say about the warranty.

Why would you use the shotgun approach to fixing it?

It is rather obviously leaking. And badly. A dye is needed to find the leak - same as you'd do with a cooling system.

But the test report "Leak Test - No leak detected" rather obviously suggests it is not leaking. So a more intelligent diagnostic approach is required ...

The leak test was (probably) only that it held a vacuum to the required standard for the required time. As others have intimated, that's not a guarantee that there are no leaks when the system is operating. That's what the UV dye is for - and leak tests which pressurise the system with nitrogen or use nitrogen/hydrogen mix and detectors.

Possibly no leak detected during the 20 minute vacuum cycle of the re-gassing in that the vacuum is held for 20m. But the vacuum is only applied to dry the system out and it's not the way it normally operates. By applying a vacuum a seal may move one way and seal the system. Remove the vacuum and pressurise the system and the seal moves to the other end of its travel and allows a leak.

When I last had a A/C re-gassed they automatically added the dye so that the could quickly check for leaks if the car was returned with a non-working.

Possibly the clue for a bad leak is that no gas was recovered as shown in the original report.

Doesn't the system also contain an oil to lubricate the seals which may have also been expelled with an original leak causing the seals to "dry out"

Working after re-gassing then not shortly afterwards is a classic sign of a bad leak. Especially since no other fault wad found.

Graham J explained on 24/05/2018 :

A leak test only tests for leaks with vacuum. Working under positive pressure it might well leak.

Thanks for the informative replies.

I contacted the Kia dealer and they wanted £100+ to "investigate" and suggested I take it back to the local garage to see what they say. I took it back and they inspected it for half hour (presumably looking for UV dye marks). The verdict was "difficult to see but either pipe or condenser". Back in contact with dealer and they said condenser covered by warrantee if not damaged or due to wear and tear. Booked in with them for 14th of next month so will update with final result after that.

But you only add enough oil to replace what was drained. Nothing came out so they only put 3 milliliters IN!

Mine holds 200 ml but can only drain 100ml.

FSM - Whenever replacing any component of the system or a large amount of gas leakage occurs add oil to maintain original amount of oil.

Run system on max cooling, with max fan and engine idling for 20-30 min to return oil to compressor.

Stop engine, discharge system, remove compressor. Drain compressor from discharge port and measure the amount. Compressor may need to be warmed to 40-50°C." /FSM

As it only drains 100ml the amount to be refilled is.

FSM - If more than 90ml came out put that amount back in. Less than

If oil contains chips or other foreign material. Flush system with refrigerant, replace drier and fill with 200ml.

If compressor is replaced oil has to be drained from it to allow for oil in system..... /FSM

People with automatic air con refil carts are little more than trained monkeys and only know how to connect it and press the buttons.

So if a lot of oil was lost in the initial leak it's been running with about 1/2 of what it needs and now it not only has a leak but the compressor could be wrecked as well.