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.

OK, I ran the car around for about 45 minutes at mostly 40-60 mph. Recycle turned OFF the entire time. I ran the fan and each temp selector at various levels. Out door temp was reading 91 on my dash. Only 49% humidity today, but the good news is, no freeze-up! :)

In the mean time, I've also found that the resistance reading across the evaporator sensor is way off spec at all temps, according to one of the guys over at MVS. (I couldn't find the specs on the web myself.)

I'm currently getting:

1400 ohms at 80 deg
1500 at 77
1700 at 65
2200 at freezing

I'm told it should read something like:

3,000 at 77 deg
10,000 + or - 200 at freezing

I may go ahead and replace it while I have the plastic panels pulled out already and a new OEM sensor can be had for ~ $30. Do you think that makes sensor not?? :)

Thanks again!

I assume you pulled it and cleaned off the dirt first? I also don't like the readings, but am glad it no longer freezes with recirc off.

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My back feels better when I sit in a Volvo seat

"... I assume you pulled it and cleaned off the dirt first?..."

Very, very little dirt on one side of the plastic "loop". I couldn't believe how clean it was. It gave me confidence that maybe the inside of the evaporator box is clean.

That 'sensor' you pulled just might be for the routine that starts up the cabin blower after the engine is turned off, This is needed to dry off the evaporator and prevent rot.
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My back feels better when I sit in a Volvo seat

"...That 'sensor' you pulled just might be for the routine that starts up the cabin blower after the engine is turned off..."

This is the one I'm replacing:

http://www.fcpeuro.com/search?utf8=✓&keywords=30665118&%2Fsearch=%2Fsearch

I know that some of the cars have a routine that runs the cabin fan for a while after shut-down to dry out the evaporator, but I don't recall ever hearing this car do that. My wife's 05 S80 will, on rare occasion, have something quieter than the radiator fan running after shut down but it sounds like it's coming from under the hood vs HVAC system. Do you know what logic may be invoked that decides whether the fan should run-on or not?

I was under the impression that the blower was initiated in the 1999 years, but perhaps it is 2001? The program compares the evaporator temp with the outside temp and can run the blower for up to 10 minutes until the temps equal. That will effectively dry off the evaporator.

My wife's car does that some times and I don't know what it is. Almost sounds like a water pump circulating to cool off the block, but that can't possibly be it. Another possibility is the evap system pushing fumes to the charcoal cannister?
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My back feels better when I sit in a Volvo seat

Just to follow up, I put a new evaporator temp sensor in Sat morning. I had loaned my ohm meter to a friend so I couldn't compare resistance between the old and new sensor. But during a test drive it did seem the compressor was cycling. Regardless of whether Recycle was selected or not, and regardless of how cold I set the temp selectors, I couldn't get it to ice up. Although the real rest comes with a nice looooong drive, I'm cautiously optimistic.

Now to get that PCV vacuum issue straightened out and figure out why my W/S washer reservoir leaks all over the garage floor. Those new Hyundai's look nice.

I love learning something new every day, that's why I am here. Another sensor to remember...

You might need a new W/W bottle, but check the bottom at the pump. The O ring might be cracked and leaking there.

The Korean seats are not that comfortable and the handling is so so. A Honda has better resale and the first tune up is at 100,000 miles. Rust used to be an issue in the rear quarter panel by the rear wheels. Dealer maintenance is much cheaper?

But, if you want a wagon and not an SUV road hog, Volvo is the best car for the price.
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My back feels better when I sit in a Volvo seat

"...Another sensor to remember......"

The sensor is a long skinny thing that pokes into the evaporator box just above the gas pedal (L/H driver car). The compressor cycles as it should now.

"...if you want a wagon and not an SUV road hog, Volvo is the best car for the price..."

LOTS of room in the V70, comfortable ride, and the 2.4 NA gives 29 mpg on the highway. Hard to find a better used car value.

"...Almost sounds like a water pump circulating to cool off the block, but that can't possibly be it..."

Funny you said that. One time a mechanic told me that "maybe" there was an electric pump that circulated coolant through the turbo after shutdown. He wasn't sure.

First, turn off the recycle switch. With auto settings, when the cabin temp is very high the system will colse off the outside air for 30-60 seconds automatically to help cool off the cabin. Besides, just using cabin air will help fry the computers which gets air drawn through it via the intake cabin air.

Second, 72F is fairly cold unless you are wearing a jacket and tie. I feel sorry for your passengers.

If there is no water leaking out of the bottom of the car at idle, then check the drain. The car drains best if the nose of the car is pointing slightly up hill. The drain is best viewed from the passenger side, but that is harder to get to because you need to remove the glovebox in order to remove the kick panels.

Even removing either kick panels will not give you room to remove and inspect the drain tube. That procedure is a royal pain.

Your system is freezing up because of the recycle switch.

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My back feels better when I sit in a Volvo seat

I'll take a drive tomorrow with recycle turned off and see what happens. A drive over to the pick n-pull would be far enough to test it :)

But I'm a bit unclear about "...Besides, just using cabin air will help fry the computers which gets air drawn through it via the intake cabin air...."

Are you saying recycle ON cools the computer with cabin air and recycle OFF cools the computer with outside air? If that's the case, wouldn't I be better off cooling the computer with 72 deg cabin air vs 95 deg outside air?

I've gotten in the habit of using recycle ON since living in the south and not wanting to introduce more moisture into the system than I have to and wanting to wring as much moisture out of the cabin as possible. Maybe that's wrong??

I'll let you know what recycle OFF does.

Thanks.

If you open the engine compartment and look, you will see a fresh air hose from the front of the car going into the computer box. At the rear of the box is a hose that goes to the cabin air intake. So long as the recirc is OFF, air is drawn in through the fresh air line, and, by default, the computer box. If the recirc is ON, no air is drawn from outside of the cabin or the computer box.

Leave the recirc OFF unless you are fighting fog on the inside of the windows and the defrost is selected. Even then, you should only use it for a minute or two.

The warmer air passing over the evaperator will keep it from icing, the water vapor will condense and drip out of the car.

I found that I NEVER need to move the dials, the ECC will try to get to the selected temperature as fast as possible. It is automatic.
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My back feels better when I sit in a Volvo seat

Wow! I new there was a ventilation duct feeding that computer box, but I always assumed the outside air source for the heat/AC system was accomplished somehow through the cowl vents.

Thanks for the info.

If I recall correctly and based on poking around I believe the air for the cabin does enter through the area by the wipers. The air is climatized either warm or cool by obvious process and with regards to the ECM box, air is further moved from the cabin outwards towards the box. Mine has a blower in it which pushes air out IIRC and "away" from the car. Thoughts here are that in either the winter or summer, the driver will contribute to the longevity and performance of the ECM and TCM by proving warm/cool air to not only themselves but to the ECM box.

When it's really hot and I run the AC for almost 5 minutes after I hear the little fan inside the ECM box continue to run so as to keep the airflow going.

I'd certainly keep the airflow to outside air rather than recirc, the system does a good job sorting out when to open and close, etc, and it minimizes the amount of stale air in the car. Second, have you changed the cabin filter recently, perhaps its dirty and not allowing full airflow through the system.

I'd also advocate checking and perhaps reseating the AC pressure switch connection with the car off, sometimes a good "reseat" is all you need.

Best,
Steve

Steve,

From your description I can see where introducing outside air into the cabin would in turn provide more cooling (or heating in the winter) air to the ECM than simply recirculating air within the cabin. When Klaus posted how the cabin circulation benefited the ECM, it was the first time I had heard that. So the ECM box must have an exhaust path. It would be interesting to compare the air flow OUT of the ECM box in both the fresh air and recycle modes to see how much difference their is.

Good point relative to the cabin filter. It's one of those things that I always "planned to do soon". I watched the Youtube video on how to R2 it so now that I'm an "expert" I will probably go ahead and order a new filter for both my 03 V70 and the wife's 05 S80.

You may be scared what you see on that filter and what has collected in their, I certainly was when I did mine for the first time. I'd bet if your filter is dirty it may be playing up and causing some of your issues. i found a stubby torx bit socket set that I got during an XMAS yankee swap worked perfect, I truly got the best gift that year! Only hard part is the awkward position you are put in when trying to do the job, takes about 15 mins and a few beers.

I like the part about the beers!!!!
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My back feels better when I sit in a Volvo seat