The air con in my '93 M5 has never worked properly whilst I've had it. It makes a very half hearted attempt at blowing cold air.
I was hoping it just needed the coolant gas replacing, but when I press the air con button, I don't hear any kind of noise that suggests the compressor is working. Should it make some kind of noise?
Also I remember hearing that the gas used in older air con systems is now illegal, and such systems have to be converted to run on the new gas. Is this true, and does it apply to the M5?
Unfortunately I suspect fixing the air con is going to be a costly exercise
My car is the same year as yours and it uses the newer style refrigerant so you shouldn't have any worries there.
On most cars when you turn the air-con on you notice a change in engine noise as the compressor saps some power, this doesn't seem to happen on the m5 So the easiest way of telling if the compressor is running is to look at the front of the engine at the bottom left (looking from the front) and you should be able to see the compressor, when its on, the centre part should be spinning round. If it spins for a couple of seconds then cuts out you just need a gas recharge (should cost around £40). If its stationery then you have a problem, good possibility that its an electrical problem.
Hope you sort it out as its lovely having working airconditioning this weather
Don't start crying yet It could just be that you have lost all of your refrigerant, the low pressure switch will not close and the compressor will not engage. I would get the refrigerant charge checked first.
Thanks again Miles. I don't think the refrigerant will have been replaced since around 1998, so it could well be just that.
I assume its a specialist job checking this, although obviously it will need replacing anyway.
BMW quoted me £120, but you mention £40 above. Is this with an air con specialist?
Originally posted by Bryn Thanks again Miles. I don't think the refrigerant will have been replaced since around 1998, so it could well be just that.
I assume its a specialist job checking this, although obviously it will need replacing anyway.
BMW quoted me £120, but you mention £40 above. Is this with an air con specialist?
Cheers,
Bryn.
Yes it was a local ac specialist (fixed a leak on my 328 and recharged for £40 !), a quick look in your yellow pages or search on yell should bring up some local to you. I wouldn't pay more than £60 for a refrigerant check/recharge.
if your car uses the later refrigerant for the A/C it should a sticker saying R 134 gas.
The aircon compressor will not engage if there enough pressure in the system.
So the 1st thing is have system checked for Gas, and if it needs filling have them add a dye which makes leak obvious with an ultraviolet light, which will make a possible leak that much easier to trace.
If after that the system doesnt work then its time to start checking the electrical side of things.
When i turn my air con on there is a noticeable rise in tickover speed and it also affects the power. The car has the misfire discussed in another recent thread and this is made worse when i turn on the AC!!
no matter which Freon you use, the system is always under pressure and the gas will seep out from seals, etc. over time.
you can check the sight glass (near the fuse box) for a rough guess of Freon in the system. Recommend taking to a A/C shop where they can connect pressure guages to 'top off' your level of Freon.
even that is somewhat inaccurate as measuring High and low pressures cannot determine total quantity in system. many shops have machinery that can suck out all the Freon, filter it, and WEIGH it, prior to putting it back in.
note: the manual tells how many pounds/kg the system should contain; not what pressure it should be - as pressure will vary with temperature and altitude.
Working my way around the car bringing it up to the high standards it deserves. I am having problems finding the sight glass for the air-con system. Old threads suggest it is under a plastic cover near the fuse box or near the 'e-box'. Can't find it near the former and don't know what the latter is! The only similar plastic cover I can find is near the air con charging valves on the side of the ECUs, however removing it reveals only a wiring harness. Probably looking straight at it but would appreciate some guidance.
Air Con questions
So the easiest way of telling if the compressor is running is to look at the front of the engine at the bottom left (looking from the front) and you should be able to see the compressor, when its on, the centre part should be spinning round. If it spins for a couple of seconds then cuts out you just need a gas recharge (should cost around £40). If its stationery then you have a problem, good possibility that its an electrical problem.
Linear Mode
