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foz
Monday 18th July 2005, 22:16
I know I may already be stating the obvious, but here are some of the things I have learned about the aircon on these beasts. If the level of gas falls, the ecc will not tell you. The first warnings will be loss of cooling ability, accompanied by more and more rapidly cycling compressor clutch. If the problem is not the gas level, but the climate operates for so long and then packs up, probably the air gap on the compressor. This causes the compressor electro magnet to overheat, and it can't overcome the air gap to re-engage. An interesting side effect of this is the engine revs racing and not falling on gearchange. If you find this happening, try turning off the ac switch and see if the problem goes away. The compressor will usually start working after the car has been off for a while and it has cooled down. To test for this if you are feeling brave you can prove this by giving the front of the compressor a tap with a long bar, if the air gap is the problem, the clutch will pull in. Do not fear though, I believe that if you undo the 10mm nut in the middle and remove the front plate of the compressor, there are shims behind, remove one and remeasure, the clearance should be between 0.4 to 0.6 mm maximum. As I learn more, I will post more.

andi t5
Tuesday 19th July 2005, 00:30
interesting stuff foz, where did you get the info on the comp clutch air gap? ive been trying to find the adjustment procedure for a while

nikgallagher
Tuesday 19th July 2005, 09:07
My compressor clutch comes in about every 2 seconds, so thought it would just need a re-gas. My local independant (without looking I add) said it would 99% be a failed condensor / evaporator (can't remember which one, but it included taking the dash off) as this always happens on 850's, and that there was even a recall on other models. Is it worth getting a re-gas in case he is talking skitsnack or will I just be wasting my money?

foz
Tuesday 19th July 2005, 09:18
God you can tell I'm a newbie, wrong name!!Andi, I know this is the procedure for a Saab compressor, but wouldn't imagine its terribly different to ours. I will be doing mine in the reasonably near future, so will let you know how I get on.
http://www.emotors.ca/Articles/article.aspx?id=1218

In relation to Niks question, you may have a small hole in the system somewhere, however, if the compressor is still cycling on and off, that suggests there is still gas in the system hence no big leak. If the system was completely empty, the pressure switch would stop the compressor coming in completely. Go for the regas first.

nikgallagher
Tuesday 19th July 2005, 09:24
Nice one Foz! Will have a go at this on the weekend I think. Much easier than having the dash out!

Martinr
Tuesday 19th July 2005, 09:26
Nik

Whilst the Condensor and the Evaporator do give trouble on these vehicles it is no way certain that they will be the cause of your problem.

If the condensor is holed all the gas will leak out, in that case the pressure switch will stop the compressor engaging at all, (this was the case with mine).

The fact that the compressor is cutting in and out (referred to as short cycling), indicates there is still some gas in the system.

Mine is doing this now because the garage that fitted the condensor have botched one of the O rings and the gas pressure has decreased.

Get it regassed, if nothing else you will be able to find out if there is a more serious underlying problem present.

andi t5
Tuesday 19th July 2005, 14:14
cheers foz i found the article on the saab site,the best preventive mantenence you guys can do on the 850 is make sure you have a pollen filter fitted, it creates havoc with the evap if you aint due to crud collecting on the evap and creating serious corrosion which rots out the evap, volvo do a retro kit well worth it

audimadmike
Thursday 21st July 2005, 22:39
Hi, A filter will certainly help as you say but also a regular evaporator clean and disinfection (say twice a year) will also remove crap and keep any smells to a minimum.
A regas is only neccessary when parts have been replaced or a gas leak has occured, LEAK needs sorting first. Short cycling is nearly always due to gas shortage.
Mike

foz
Thursday 18th August 2005, 11:06
How can I tell if mine has a pollen filter fitted, and how do I fit one if it doesn't.

swordy21
Thursday 18th August 2005, 11:48
How can I tell if mine has a pollen filter fitted, and how do I fit one if it doesn't.

Check here: http://www.volvospeed.com/pollenfliter.php

Bear in mind this is a US site so reverse left and right. Your filter should be on passenger side (or RHS looking at front)

Cheers

The Flying Banana
Thursday 18th August 2005, 11:56
RE Air con etc, on mine on start up on the temp control apnel there is two orange LED lights that flash in a succession of times....bout 20 or 30 i think . No cold air ..never has since i got it but i notice that when teh air con button is pressed there is no noise, no drop in revs as though something has cut in etc ( i am comparing this to other cars with air con ) am i looking at big bills you think ?

audimadmike
Friday 19th August 2005, 08:59
RE Air con etc, on mine on start up on the temp control apnel there is two orange LED lights that flash in a succession of times....bout 20 or 30 i think . No cold air ..never has since i got it but i notice that when teh air con button is pressed there is no noise, no drop in revs as though something has cut in etc ( i am comparing this to other cars with air con ) am i looking at big bills you think ?

If it doesn't work at all probably no gas or very short which will mean the LP switch will not pass any current.
The most popular area for leaks are the O ring connections on the condensor (radiator)
Engine revs always increase with compressor operation.
Do you have climate control rather than a/c?
Mike

foz
Friday 19th August 2005, 09:21
The Flying Banana, The flashing lights indicate a fault within the climate unit. If you have 2 orange lights, this is a climate control unit. To do a quick test on the air conditioning compressor, turn on the ac in the car, open the bonnet, and at the back of the engine bay where the 2 ac pipes go into the car, there is a Low Pressure switch in 1 line. Disconnect this and very briefly bridge out the 2 terminals. If the engine revs rise, then the compressor clicks in, your gas level is too low to register, and needs recharging. The gas does escape over time, or you have a leak somewhere, in which case be prepared for a long hunt!. If the engine revs don't rise, and the compressor doesn't click in, the ecu or relay behind the climate unit could be at fault. If you turn the ac switch on and off with the engine running, you should hear a faint clicking sound behind the ecc control panel . If not relay or ecc faulty. Try this out and get back when you have.

misterpeck
Monday 22nd August 2005, 12:32
RE Air con etc, on mine on start up on the temp control apnel there is two orange LED lights that flash in a succession of times....bout 20 or 30 i think . No cold air ..never has since i got it but i notice that when teh air con button is pressed there is no noise, no drop in revs as though something has cut in etc ( i am comparing this to other cars with air con ) am i looking at big bills you think ?

Had a similar problem with my a/c. Had it regassed and it was fine for all the time just ideling on the drive, but 5 mins of driving it started blowing warm air.

Spoke to main stealer and booked her in for a/c service which would highlight the problem. As for big bills, T F B, you are not wrong.
After fitting new Compressor , Evaporator and Accumulator, full a/c service the bill was £1938.91

Thank god the majority of this was covered by the warrenty I got with the car. My bill for this was only £258.46 and that is with the discount that I get.

Hope you manage to sort yours out for a fraction of the price if you have no warrenty on the car.

Mrsmopp
Monday 22nd August 2005, 12:35
the bill was £1938.91

Thank god the majority of this was covered by the warrenty I got with the car. My bill for this was only £258.46 and that is with the discount that I get.

Hope you manage to sort yours out for a fraction of the price if you have no warrenty on the car.

That warrenty of yours never ceases to amaze me - you jammy ghet LOL

x

misterpeck
Monday 22nd August 2005, 12:51
That warrenty of yours never ceases to amaze me - you jammy ghet LOL

x

And only 5 months left.

Best see what else is gonna go wrong with me little beasty.......:D

wellsy
Monday 22nd August 2005, 17:39
sorry if this has already been answered ,my air con was working fine but the car has been laid for about a month and now no more ice cold air, when i swithch the air con on the compressor kicks in and engine revs for a couple of seconds and will then click off this happens constantly untill i turn the air con off.
could this mean it is maybe short on gas as it was working ok until being parked up .
thanks wellsy.

audimadmike
Monday 22nd August 2005, 18:01
sorry if this has already been answered ,my air con was working fine but the car has been laid for about a month and now no more ice cold air, when i swithch the air con on the compressor kicks in and engine revs for a couple of seconds and will then click off this happens constantly untill i turn the air con off.
could this mean it is maybe short on gas as it was working ok until being parked up .
thanks wellsy.

YOU are short of gas!
The compressor starts up at high pressure and as it pumps and sucks the suction pressure lowers until the LP switch is triggered by too low a pressure, in normal use this would happen only on very cold days or when the evaporator is starting to frost, providing the stat hasn't already shut the system down.
SO the leak needs finding, reparing and then vacuum pumped followed by recharge £55 +.
Mike

dan_burdock
Wednesday 14th December 2005, 08:02
Is there a recommended time period to have your aircon re-gassed as I am sure mines due! Had it three years and it clicks every 20ish secs when in idle is this signs of a re-gas :bricks:

NugentS
Wednesday 14th December 2005, 12:10
Hi, A filter will certainly help as you say but also a regular evaporator clean and disinfection (say twice a year) will also remove crap and keep any smells to a minimum.
A regas is only neccessary when parts have been replaced or a gas leak has occured, LEAK needs sorting first. Short cycling is nearly always due to gas shortage.
Mike

The disenfect I can understand - you simply gas the car with the aircon on. But how do you clean the damn thing without taking the car apart?

I have just had my evaporator replaced and as I plan on keeping the car till it falls apart I would like to NOT have to pay for another evaporator in 4+ or so years time.....

I change the pollen filter every service - what more can I do....

Sean