I am facing a complex situation of coolant leak on my 2016 Volvo XC60 (D4204T4 diesel engine), situation that I will tray to explain it in another (long) post. But here I'm just interested in sharing a doubt about how engine fans have to work. Let me try to explain...
- When I turn on the air conditioning, the 2 fans always start immediately, at a reasonably high speed
- When I turn a/c off, they go to a slow speed after a few seconds, and very soon they turn off. In total they turn off in 30 seconds o less.
- But with the a/c off, I don't see the fans activated never. No matter how much time is the vehicle running idle at service temperature, or if you accelerate a bit (2.000 rpm o less) during some minutes... the fans never activate.
- The temperature gauge never goes up, don't see the car overheating, ever.
- Another test... If after reaching service temperature, I turn the heating on, the temperature indicator drops a little, one inch o less. And it rises little by little until in 2 or 3 minutes it reaches the service temperature again. I suppose that is because the thermostat opens to heat the coolant sooner and this in turn heats the cabin.
Without A/C on I have only seen fans in operation once, a while ago, coming from a couple of hours of continuous operation in city.
Unfortunately, I do not have an OBD reader to provide coolant temperature data, sorry.
If anyone observes a different behavior in their D3 or D4 engine, then happy to share the information.
Thank you very much in advance
