A/C inconsistant

xyourobob · Post by **xyourobob** » 07 Oct 2017, 17:55

Our 2011 XC60 A/C has started to act up. One minute it's blowing nice frigid air and the next it's blowing warm air. I have confirmed that the fans in the engine compartment are working just fine. I also hooked up my auto store cheapo recharge rig and it says the Freon is in the green zone. Anybody have any thoughts on narrowing down the problem?

OnnoJ · Post by **OnnoJ** » 09 Oct 2017, 14:09

Have read about similar symptoms on a Dutch forum. Replacing the interiour temperature sensor did the trick...

Post by **jimmy57** » 09 Oct 2017, 19:43

That car has a variable displacement compressor. The solenoids on compressors of ll makes with that feature have issues with the solenoid getting bore wear (like shift solenoids in auto transmissions....) and not working for a few minutes or quitting cooling than then coming back. The temp sensor for evaporator can cause the same issues.
Diagnosis is to monitor evap temp sensor in CCM, compressor control solenoid in ECM and have gauges on a/c watching high and low pressure. If it is the evap temps sensor then it will be too far off true vent temp. If the solenoid is sticking then the solenoid duty cycle will be 75% or a bit more but low side and high side pressure will be almost equal since compressor will be stuck in low displacement position.
Replacement of solenoid requires evacuating a/c as the solenoid in in the area of compressor with refrigerant pressure.

Post by **oragex** » 10 Oct 2017, 04:32

jimmy57 wrote: ↑09 Oct 2017, 19:43 That car has a variable displacement compressor. The solenoids on compressors of ll makes with that feature have issues with the solenoid getting bore wear (like shift solenoids in auto transmissions....) and not working for a few minutes or quitting cooling than then coming back. The temp sensor for evaporator can cause the same issues.
Diagnosis is to monitor evap temp sensor in CCM, compressor control solenoid in ECM and have gauges on a/c watching high and low pressure. If it is the evap temps sensor then it will be too far off true vent temp. If the solenoid is sticking then the solenoid duty cycle will be 75% or a bit more but low side and high side pressure will be almost equal since compressor will be stuck in low displacement position.
Replacement of solenoid requires evacuating a/c as the solenoid in in the area of compressor with refrigerant pressure.

I'm guessing these newer designs are more efficient , but boy what a trouble when these more complex things break. Sometimes I would pass the 5% extra efficiency.

Post by **jimmy57** » 10 Oct 2017, 07:09

They use less fuel. The biggy is that the compressor displacement has larger displacement and at idle and lower engine speeds it can cool better. Volvo uses a clutch (many save the few bucks and only use a drive damper with a shear plate if compressor were to seize) but it only comes once per key cycle so clutch gap problems are gone. The Volvos with VD compressors cool great at idle. In Texas that is a big deal.

xyourobob · Post by **xyourobob** » 10 Oct 2017, 17:05

Thank you for everybody for the feedback, this sounds like one of those situations that I will not be able to diagnose due to not having the right equipment in my garage. I will schedule an appointment with a local indi, unless somebody has a way of diagnosing this without gauges and Vadis?

xyourobob · Post by **xyourobob** » 25 Oct 2017, 18:08

jimmy57 wrote: ↑09 Oct 2017, 19:43 That car has a variable displacement compressor. The solenoids on compressors of ll makes with that feature have issues with the solenoid getting bore wear (like shift solenoids in auto transmissions....) and not working for a few minutes or quitting cooling than then coming back. The temp sensor for evaporator can cause the same issues.
Diagnosis is to monitor evap temp sensor in CCM, compressor control solenoid in ECM and have gauges on a/c watching high and low pressure. If it is the evap temps sensor then it will be too far off true vent temp. If the solenoid is sticking then the solenoid duty cycle will be 75% or a bit more but low side and high side pressure will be almost equal since compressor will be stuck in low displacement position.
Replacement of solenoid requires evacuating a/c as the solenoid in in the area of compressor with refrigerant pressure.

I printed out a copy of your posting for my indy and he called to confirm it appears to be the variable displacement solenoid, he doesn't show being able to buy this part with his suppliers and is going to call Volvo in the morning to see if they will sell this part on it's own or Volvo will only sell the compressor as a whole. If they strike out can you recommend a supplier for the solenoid and a brief description of where it is? I'll have the indy vacate the system, I'll replace the part and have them re-charge the unit. Thanks again for your help

Post by **jimmy57** » 25 Oct 2017, 21:15

It is on the side of the compressor held in by a snap ring and sealed by an O ring. I think Volvo services them for all the VD compressors now.
They are also sold by some of the a/c suppliers on EBay. The same compressor is used on that year model Land Rover LR2. LR@ uses the same engine, trans, and AWD components.