Volvo 1995 850 Air Conditioner problems

I was wondering if it is normal to hear a clicking sound when the air
conditioner is on? It seems like a valve or something is turning on and
off every 10-15 seconds or so.

This has been happening for quite awhile for a couple of years, and the
history of the car goes like this:
- about 2 years ago, air conditioner stopped blowing cold air. I
noticed a clicking sound.
- I took it to an independent repair place that specialized in volvos.
They said it just needed to be recharged, so I recharged it.
- a year later, the air conditioner stopped blowing cold air again. I
noticed the clicking sound again.
- I took it to a different independent repair place (I moved). He said
it was a leaky compressor. I paid about $1000 for parts and repair.
- 2 months later, I am noticing the clicking sound again. However, the
air is still cold.

Since the air conditioner is still blowing cold air, I am not sure
whether there is something wrong with it. However the 10-15 second
clicking cycle is exactly what I used to hear when the air conditioner
was having problems. So I tend to think that there is still something
wrong with it.

I would be interested to hear anyones thoughts on this! Thank you very
much.

 

That's the indication that the compressor is short cycling, caused by a
low refrigerant level. On cooler days the A/C will appear to work fine,
but will not be very cold on hot days. Slowly this will get worse as
more and more leak out. If you look at the front of the compressor,
you'll see the front center of the pulley stop and start in time with
this clicking.

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

These vehicles have a history of the evaporator failing in a way which
causes leaks. It is a nasty replacement procedure as just about the
entire dashboard area needs to be taken apart to get to it.

The fast cycling is probably due to freon levels getting low. An A/C
pressure gauge attached to the low side port will probably tell you if
the freon is getting low or not. You *might* buy a little time by
recharging with some of the freon which has stop leak included, that
seemed to help my '96 850 a great deal. Luckily I didn't yet have to
replace the evaporator on mine.

John

 

Thank you to both of you for the response.
I will see if I can get it looked at again.

 

It would be interesting for me to know what you find out of. I have the
same problem with a cycling compressor. Made a leak test which
showed that the compressor was leaking using a much too high pressure
in the test. Have you changed the compressor without any better result?
Others teel me that same can happen when the filter is near to block.

Cheers Per

 

Rather than the filter, I'd suggest starting by washing the condensor (in
front of the radiator) out with a hose. A nozzle on a garden hose works
well. Dirt build-up on the condensor can raise the pressure a lot. Even if
that's not the problem, it won't hurt and is cheap and easy.

Mike

 

Thanks Mike
I will try this. How is it? Should the condenser be cold on the top and warm
on the
bottom or opposite?

Cheers Per

 

The condensor should be evenly warm top and bottom. The compressed gas is
fed in at the top and condenses to drain at the bottom... same temperature
but with the heat of vaporization removed. The liquid stays warm until it
reaches the evaporator, where suction from the compressor boils it off as
gas and carries the heat of vaporization away with it.

Mike