2002 V70 2.4T When does Radiator Cooling Fan Activate?

Post by **KidsV70** » 30 Jun 2020, 22:31

Hey folks,

Had a problem recently- the V70 started blowing coolant out of the overflow tank. We were sitting in traffic with the AC on, but I don't know if it overheated or not- the kid was driving and I was paying attention to her driving (she only has a learners) and where to get it off the road safely, not the temp gauge.

So we got it towed home and added coolant and replaced the overflow tank cap. I ran it in the driveway for 15 minutes on a warm day (85F at least, sunny), and it was fine.

BUT- the radiator cooling fan did not activate! I was able to command it to operatve via VIDA, and it works in all 3 speeds.

So my question is under what conditions does the car activate the cooling fan?

My next plan is to have her drive it some with me using VIDA to view temperatures more precisely than the gauge, but I'd really like to know what the spec is. I've had no luck getting it out of VIDA. And nothing on the web either.

Thanks in advance!
Bert

Post by **jonesg** » 01 Jul 2020, 02:04

turn the AC on, fan should come on,
if no, check the power plug on the fan..
if yes , does the top hose get warm, checking for thermostat opening at operating temp. Could be engine temp sensor at thermostat.

Post by **KidsV70** » 01 Jul 2020, 11:29

jonesg- Thanks! Yup, the AC was running while in the driveway. And working hard as the car started out with an interior temp of 108F!

Time for more diagostics!
Bert

Post by **jonesg** » 01 Jul 2020, 12:28

KidsV70 wrote: ↑01 Jul 2020, 11:29 jonesg- Thanks! Yup, the AC was running while in the driveway. And working hard as the car started out with an interior temp of 108F!

Time for more diagostics!
Bert

shouldn't overheat if the cooling fan works, maybe the thermostat isn't opening.
Feel for hot coolant in the top hose at normal engine operating temp.

If nothing comes up as the culprit then you'll need to check for blown head gasket forcing compression gas into the coolant system.
Napa sells block tester fluid, blue dyed, if it turns yellow there are exhaust gasses in the coolant.
Happened to my older volvo, I knew something was up as the coolant bottle was stone cold but under pressure when I opened the cap.

Post by **abscate** » 03 Jul 2020, 04:13

My 1999 cycles between 87C and105c, with 105c being when the fans come on and take it back to 87C,the thermostat temperature.

105C is 221 Fahrenheit for reference. It’s possible you could idle and not trigger the fan in the driveway

Post by **oragex** » 03 Jul 2020, 06:50

Replacing the cap was the first thing to do indeed. See how it goes from there. If you notice the gauge starts moving past 12, turn off the AC, and if the fan doesn't start spinning then there may be a problem. From my memory, my gauge was still sitting at 12 when the fan kicked in at perhaps 105C or so but that only happens stuck in traffic in hot days, these radiators are really good at cooling down, at least on the non turbo engine

Post by **jimmy57** » 03 Jul 2020, 09:17

Do a visual of the fan, even use a mirror. The fan speeds are variable and it runs slower than the commanded low speed. When parked if the fan doesn't come on on a 90 degree day the a/c compressor will shut down due to excess high side pressure. If the a/c pressure is only 200 psi then the fan runs on a very low speed and the a/c pressure holds at acceptable pressure with low fan and then will only speed up if coolant temp goes up. Use VIDA or other scan tool to read coolant temp. The coolant temp should be correct for upper radiator hose temp. If coolant temp reads 74 on scan tool and the the upper hose nearly blisters you when you touch it then the coolant temp sensor is the issue.
If the fan is not coming on AT ALL then the fan issue needs to be resolved. There is an a/c high pressure sensor screwed into the receiver drier next to condenser (front bumper skin comes off for service) and it requires refrigerant discharge to replace. It is a readfing on VIDA and on some high level scan tools. at 15 bar/1500 kpa/ 1.5 Mpa/ 225 psi (scan tools can show it in any of those units) then fan should run. TO properly diagnose the sensor you need to compare a/c gauge set pressure to scan tool pressure to see that they agree.

Post by **KidsV70** » 11 Jul 2020, 10:11

Hey everyone!

Thanks for the info everyone! Sorry I haven't been on in a while... had some other things going on. Had a chance to do some diagnostics yesterday. Drove the car with AC on about 4 miles. Coolant temp got to 105C, no fan, and most tellingly, I could not command the fan on with VIDA.

Interestingly enough, there are (and have been) issues with the AC. It comes on and off, and the line on the passenger side of the vehicle freezes. I had assumed low refrigerant and hadn't bothered to get it worked on since it gets driven so little. But based on jimmy57, I suspect part of the "problem" is actually what's designed in the system- AC cutoff.

Clearly something is failing when the engine is hot. Is there a fan relay underhood? I'm just now starting diagnostics.

Post by **KidsV70** » 11 Jul 2020, 10:40

Okay. Answered my own question. Via Manuals.lib I found a V70 wiring diagram. It shows the ECM, the fan module, and the fan. And that's all, folks!

So if the fan isn't working when hot, that suggests the control module has an intermittent fault. Make sense?

Thanks!!

Link to the Manuals.lib page: https://www.manualslib.com/manual/533732/Volvo-V70.html

Post by **KidsV70** » 11 Jul 2020, 13:32

Okay, and some more diagnosis. Used VIDA to command the fan on. No fan function in any of the 3 speeds (25%, 50%, 100%).. I did some careful poking with an old windshield wiper blade, and the motor is tight. I can turn the fan blades but not as easily as I'd expect. I'm thinking deceased fan motor at this point. Thoughts?