2003 V70 A/C Freezes Up. Evap temp sensor 30665118

Post by **chrism** » 31 May 2014, 16:04

2003 V70 Base, 2.4 N/A 200,000 miles.

I’ve got an issue with my A/C wanting to ice up. For one thing I don’t think the compressor is cycling off. Scenario: Driving along for about 20 minutes minimum. (Doesn’t freeze up on short drives.) It doesn’t seem to matter where the temp dials are set, although it might be that it doesn’t freeze up quite as fast if we run it up around 72-ish. Usually the Recycle Cabin Air button is “On”. The big airflow control buttons are set to “Auto”. So any way, we’re driving along and I’m comfortably cool and everyone else in the car is yelling at me because “it’s freezing in here.” Then gradually the airflow volume starts to decrease down to nil. The temporary fix is to shut off the A/C Compressor button and let the fan continue blowing fairly high. After about a minute the airflow begins to recover back up to the set speed and it continues to blow quite cool for about a full minute before we have to punch the compressor back on. Then in anywhere between 5-20 minutes, depending on conditions, we repeat the whole process.

So far: I have taken a vacuum cleaner and sucked out that little thermostat vent thing. A lot of lint came out.

Next I would like to verify that the condensate is draining properly. It appears the drain hose exits the cabin just above the gas pedal. I want to remove the drivers side upper kick panel so that I can hopefully get a better look at the drain and blow the hose out.

Questions:
Besides the two torx screws, what combination of prying and pulling is required to remove the kick panel in one piece?

What else could be the problem? Is there a temp sensor in the evaporator coil that might be at fault by not calling off the compressor?

Any other ideas?

Thanks.

Post by **jimmy57** » 31 May 2014, 16:27

above and to the right of the accel pedal is a sensor stuck into evaporator housing to sense air temp off the evaporator. That sensor is read by the CCM and it drops request to ECM for compressor in order that compressor cycles to prevent freezing (this is on P2's).
That sensor is either defective or it has an accumulation of fuzz or dirt on it.

AusV70 · Post by **AusV70** » 31 May 2014, 16:35

Thanks I was going to look at mine today!
Although mine isn't freezing instead it stops cycling and blows warm smelly air. I removed the cabin filter and it was blocked and this helped a bit. Now I will check the sensor.
Ausv70

AusV70 · Post by **AusV70** » 31 May 2014, 16:41

Quick question. I am geussing Jimmy57 and chrism your cars are left hand drive? Is the sensor located on the left or right kick panel?
Ausv70

Post by **chrism** » 31 May 2014, 17:14

Thanks for the quick reply.

Do I need to drop the kick panel down to access the sensor? If yes, I need to figure out how. 11 year old plastic isn't very forgiving. Then again, I'm just redneck enough to trim the corner out of the panel if I can't figure out how to get it out of there. I had both screws out but it was still snapped into place.

Post by **jimmy57** » 31 May 2014, 18:10

The panel has the two tx 25 screws and it has push in metal clips at the edges. Run a pry tool (blade screw driver) across the seam and pry it down then slide it to the rear to free the front edge.

Post by **MoVolvos** » 01 Jun 2014, 04:04

_

Cooling Coil or Evaporator Coil Ice-up or Frost Over
http://inspectapedia.com/aircond/ACCoilFrost.htm

Excerpt

"In a refrigeration class demonstration, we learn that one could, given no other data, determine the proper refrigerant charge or better, the proper adjustment of an adjustable refrigerant metering device (Thermostatic expansion valve) by adjusting the refrigerant flow rate into the coil so that the frost line stops just before the end of the coil."

Due to low refrigerant the frost turned into icing is beginning much further up in the Evap coil rather than the end. Put a gauge on the low side and use the Pressure Temp Chart for 134A to check for low refrigerant.

https://www.google.com/search?q=134a+pr ... B448%3B232

Blessings,
BKM
_

Post by **chrism** » 01 Jun 2014, 09:14

BKM,

Those links lead to some interesting info! Although I don't have any reason to suspect an under- (or over-) charge of refrigerant, I may have that looked into if I don't solve it otherwise. I'm just trying to consider all of the free, or nearly free, possible fixes first. I don't own my own gauge set for checking high and low pressure sides of the system. Maybe it's time for a tool purchase?

Post by **coflynn** » 01 Jun 2014, 09:27

Although mine isn't freezing instead it stops cycling and blows warm smelly air.

For this case - check the AC clutch gap. It's easy to measure with a feeler gauge, I don't have a specific link but searching for 'AC clutch shim' and 'bread clip fix' should give you some links.

Post by **jimmy57** » 01 Jun 2014, 11:58

Low refrigerant on P2's shows for a long time as different temps on the different vents due to evaporator not being chilled over its entire surface. On automotive units freezing is rarely seen due to low refrigerant. It is very common on non-automotive units running R22, R402, and other high pressure refrigerants.