A/C starts off cold then blows warm

[S40Tex]

So do you think that removing this shim from the compressor shaft driven pulley will fix the issue? Or should i also replace the magnetic clutch?

[jimmy57]

remove the shim only. Clutch costs almost as much as compressor.
The problem is due to the distance. The magnetic force weakens a lot in a few thousands of an inch. When the magnetic coil winding gets warm the resistance increases and decreases the current and the magnetic force. The gap having worn to a greater opening is enough to make the driven plate not pull into the drive plate. If compressor is quiet and a/c cools then the sole thing to do is adjust the gap.

[S40Tex]

I would love it if i did not have to replace anything on my car. Simply removing the shim as opposed to buying some expensive replacement piece is always better.

However, i have no idea where the A/C Compressor on my car even is, let alone what the shim looks like. Has anyone done this on an s40 before?

[IownthreeVolvos]

I began having this same problem with my 2000 V70XC. It is a different model but my experience so far may give some insight as to how you should approach your issue. My car's symptoms are the same; the A/C runs cold and suddenly blows warm air; after turning it off for a brief period, it blows cold again. My dealer looked at it and would not give me a definitive answer; however, the service director said I will need to replace the evaporator for approximately US $1,500. I took my car to an independent mechanic, who is a Volvo specialist; and he believes the problem is in the fan clutch, which does not remain engaged. He said replacing it is an expensive repair but will be less than US $1,500, although he has not given a formal estimate to me. When my A/C works properly, it blows ice cold, which leads me to believe my evaporator is fine and that the private mechanic's diagnosis is correct. I think you may wish to get more than one opinion. Good luck.

[S40Tex]

Yea, i ended up getting the A/C Compressor replaced for just under $1000. It was the clutch that was going, but if you just replace the clutch, the cost is only a little less than the whole A/C Compressor, so i had it all replaced... Works perfectly fine now

[Cymerax]

Count me in, I've got the exact same problem on my 2007 S40 w/108,000 miles. Since I can't afford a $1000 - $1500 replacement, could some please elaborate a bit on where to find the aforementioned shim and how to remove it? Any help would be very much appreciated. Thanks in advance

[VolvoKev]

There are several great posts on how to complete this. This link was a good one. I recently did the 'bread clip' fix, using a zip tie instead of the clip, and so far so good. I think I will be re-shimming soon though, because it is a much more secure fix.

[jrkoski2002]

I had the same thing: it was the A/C clutch. About a $650 repair...but fixed the problem. V50

[marcusb05S40]

I went in to the shop and talked with the head tech there. He seem very knowledgeable and said that he has seen tons of s40's where the magnetic clutch on the a/c compressor can no longer engage when hot.

My understanding is that the clutch abrades over time and always returns to the original position unlike brake calipers that adjust position as the brake wears out. Since the clutch plate returns to the original position the magnet is no longer strong enough to engage the clutch for such a distance. The onset of this occurs when the compressor is very hot, because the magnetic field from the magnet is lower when heated.

However, I was told the clutch life is design to fail just before the compressor, so under certain circumstances this cap/relay fix is just a band-aid that might last for an unknown amount of time (unless you really get into the permeation of the magnetic field)

If anybody has seen one of these cap/relays that will work with a S40 can you please post it.

[Talamant3z]

Re shim job same issue and got my re shim job and no more hot air cost 140 too so not to expensive