This is probably a question for DaveN or elekie&a/c doctor
The car is at it again!!
The air con (climate control) on my 2001 Vectra was not cooling particularly well so a friend regassed and tested for leaks. All has been OK but recently it doesn't seem to be cooling as it should. Then needed the air con last night to demist the interior but it seemed to be struggling to do that.
When the air con is selected there is a long sucking sound from under the dash before anything starts to happen. The air con then seems to continue with little sucks from time to time.
I have also noticed that if the engine is turned off with the air con running there is a sound similar to a jet engine running down. I have checked the electronics with a diagnotics reader (but not with the air con running) and this did not show faults
I suspect that I have a slow leak and will get someone local to have a look, but any ideas of cause and cost would be appreciated.
s
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The sound similar to a jet engine spooling down is probably the condenser fan under the bonnet, by radiator. B I L's Vectra and my Xantia both make the same sort of noise.
This suggests that the air con has at least enough gas to run or a low pressure switch would inhibit it.
This suggests that the sucking sounds under the dash aren't the sealed aircon system itself but a fan/ducting/pollen filter/control flap operation problem.
It may be worth investigating those first.
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Thanks MJM - all ideas are welcome before I spend a fortune.
I have the diagnostics routine for the climate control system so will go through that at the weekend if I get time! There are various voltages to measure at points around the system but I cannot remember if the aircon has to be running to do this. I did not have it running when I put the diagnostics on the car so it may have a fault that shows only when operating.
I did wonder about some sort of flap problem as the heating is sometimes a little lacking - this could be due to the combination of interior / exterior / engine temperature being all such that the system does not need to push warm air into the cabin.
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My first, and probably easiest, port of call would be the pollen filter. Don't know how easy it is to get at on the Vectra but the Xantia is simple. The amount of stuff it traps is unbelivable. For the cost of it it's not worth not changing, if you see what I mean.
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Piece of cake on the Vectra as it is just under the scuttle plate. I looked at it a few weeks ago and it seemed OK but I can get one for a few pounds from a loal factor. Worth a try!
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A long sucking sound from behind the dash can be a symptom of inadequate gas charge/quantity and/or air in the system,thus the problem with poor cooling.Did the friend that recharged the A/C carry out a vacuum of the system for at least 30 minutes?hth
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Gas recharge needs to be very precise on a vectra & I always do it with gauges/pressure reading rather than gas weight & once done will easily pull down to a couple of degrees. Depending on the pump the capacitys for refilling do vary.
The sound you hear could be the gas going through the control valve after you have turned the engine off. It needs a pressure check & did it have a good vacum before it was regassed. I see so many do squirt & go's it gives the rest a bad name & if it hasn't been vac'ed you could be sitting on a time bomb!
Doc
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In reply to both injection doc and elekie&a/c doctor
I watched whilst the system was gassed and saw that it was vacuumed but for how long I cannot say - certainly not a quick vac. I was told that the pressure check was OK but as it was regassed last year with similar symptoms I am beginning to suspect a slow leak somewhere.
I also saw that the gas was put in by weight
What would be the effect of not having the system vacuumed?
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Systems are vacuumed out to remove air and moisture. It is possible to do a leak test as well by watching for the vacuum to decay. If air is left in the system then it will tend to increase the high pressure side of the system. Any moisture left can cause an ice blockage at the expansion valve which will stop the refrigerant circulating until it has melted.
I'm not sure about car air-con but in a domestic system the moisture can react with the oil to form an acid. In a domestic system then the acid can remove the varnish from the motor windings. A car compressor, of course, doesn't have an electic motor.
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