SwedeSpeed - Volvo Performance Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
2,633 Posts
Discussion Starter · #1 ·
My R has just started exhibiting some odd behavior with the A/C. Three times now, it has randomly shut off. The fan keeps running normally, but the air goes luke-warm and humid (distinctly not air conditioned). If I hit the A/C off button, the fan speed drops to almost nothing even with the fan manually set (weird). Switching A/C back on does nothing most of the time, except raising the fan speed back to normal. I usually have to fiddle with the A/C off and on, fan speed, and Auto climate buttons and eventually I'll hear a strange creaking sound from behind the center vents and the A/C suddenly works again. I can hear the compressor engaging when I cycle A/C off and on, but the air will remain luke-warm until the sound occurs.

Air blows ice cold once it works again. No codes or anything in VIDA. It's like the CCM just decides to close off the coolant from the evaporator. Never had any A/C problems before. Could it be the expansion valve?
 

·
Registered
Joined
·
117 Posts
if the compressor stays running it shouldn't be an issue with the actual refrigerant circuit. I was also under the impression that Volvo was using a fixed orifice tube and not an expansion valve, so I'm pretty sure that's not the right tree to bark up.

What it sounds like is one of the vent control solenoids is sticking.
 

·
Registered
Joined
·
8,055 Posts
Assuming its not a controller issue, check your A/C compressor clutch gap, once it gets to large it will make clutch engagement become intermittent during hot conditions.

As far as easy solutions for that issue, google 'chip clip A/C repair, though I did mine with tiny tie wraps instead.
 

·
Registered
Joined
·
228 Posts
My non R s60 has also had a couple recent intermittent issue, but mine the compressor stops running. This happened a couple weeks ago and now seems to be working. So not sure what is brewing there.
 

·
Registered
Joined
·
921 Posts
If it's the clutch gap that's the problem, do the broom handle test. When the car is running, and the AC has stopped working, pull over, leave the car running, and use a broom handle to press against the AC pulley, pushing it inward towards the compressor. It doesn't have to be super hard.

If the AC starts blowing cold again, then you need to either do the zip-tie fix or actually service it properly by measuring the clutch gap, pull off the compressor pulley with a pulley puller and and put different washers in there (narrower than before) so that the clutch gap is tightened back into spec. Robert has several good videos on this on youtube for an 850, same basic idea: https://www.youtube.com/results?search_query=volvo+850+ac+pulley

If the AC doesn't start blowing cold again after the broom handle test, then you've got some other kind of problem.
 

·
Registered
Joined
·
6,566 Posts
Scan it with VIDA and see what codes come up. Also check refrigerant level. The low pressure port is under the power steering resivoir.
 

·
Registered
Joined
·
117 Posts
If he can hear the a/c compressor engaging and disengaging when he presses the button that pretty much rules out the clutch. No need to go down that road if its not needed. When the clutch isn't engaging properly the compressor is not running.

If his compressor is running he is also not low enough on refrigerant to be causing his issue. Again if the compressor is running normally and cycles on and off as it should then the problem has to be inside the car and not under the hood.
 

·
Registered
Joined
·
2,633 Posts
Discussion Starter · #9 ·
Thanks for the input guys. I'll check the gap for the compressor just in case. If that's not the problem I'll just keep my fingers crossed that it holds out until cooler weather, as in the cabin problems sound expensive. I'll check in VIDA to see if there's anything to help diagnose, but any pointers as to where to look, feel free.
 

·
Registered
Joined
·
1,407 Posts
If he can hear the a/c compressor engaging and disengaging when he presses the button that pretty much rules out the clutch. No need to go down that road if its not needed. When the clutch isn't engaging properly the compressor is not running.

If his compressor is running he is also not low enough on refrigerant to be causing his issue. Again if the compressor is running normally and cycles on and off as it should then the problem has to be inside the car and not under the hood.
The electromagnet coil gets hot from being energized and from conducted heat from engine. The strength of the magnetic field goes down when wire gets hot and becomes more resistive. The gap then becomes an issue due to the force needed to pull driven into drive pulley is proportional to gap.
This set of symptoms is VERY common on many makes including Volvos. If the a/c system is otherwise working fine and suddenly goes off on a 100K+ mile P2 after it cools car off and compressor then is cycled then clutch gap is #1 on the list.
Loosen rear subframe bolts and then support front of subframe with floor jack. Remove front subframe bolts and let the subframe down 3-4 inches for compressor access. Take off the center screw and pry gently on both sides of compressor clutch plate. I have found it rare to need a puller but it might be needed. Once the plate is slid off there will be two washers in the hub. Sometimes one is on compressor shaft and one in hub and of course, they could also fall out in handling. Remove the thicker and slide the plate back on and install bolt and check gap. No less than .010"/.25mm and no more than .030"/.75mm. I always go for less gap to make sure clutch gap wear doesn't become a problem again before compressor is worn out.
 

·
Registered
Joined
·
117 Posts
The electromagnet coil gets hot from being energized and from conducted heat from engine. The strength of the magnetic field goes down when wire gets hot and becomes more resistive. The gap then becomes an issue due to the force needed to pull driven into drive pulley is proportional to gap.
This set of symptoms is VERY common on many makes including Volvos. If the a/c system is otherwise working fine and suddenly goes off on a 100K+ mile P2 after it cools car off and compressor then is cycled then clutch gap is #1 on the list.
Loosen rear subframe bolts and then support front of subframe with floor jack. Remove front subframe bolts and let the subframe down 3-4 inches for compressor access. Take off the center screw and pry gently on both sides of compressor clutch plate. I have found it rare to need a puller but it might be needed. Once the plate is slid off there will be two washers in the hub. Sometimes one is on compressor shaft and one in hub and of course, they could also fall out in handling. Remove the thicker and slide the plate back on and install bolt and check gap. No less than .010"/.25mm and no more than .030"/.75mm. I always go for less gap to make sure clutch gap wear doesn't become a problem again before compressor is worn out.

I understand the gap problem. However this is per the OP:

eventually I'll hear a strange creaking sound from behind the center vents and the A/C suddenly works again. I can hear the compressor engaging when I cycle A/C off and on, but the air will remain luke-warm until the sound occurs.
That's does not sound like a compressor clutch problem. I understand its a common problem on these cars but please read symptoms before jumping to conclusions.
 

·
Registered
Joined
·
1,140 Posts
The creaking could also be the temperature blend door binding up and not moving, allowing hot air to come out
 
1 - 15 of 15 Posts
Top