I'm a newbie here, thought to join to get and share information from other fellow Volvo drivers.I have had a 2006 XC70 2.5T here in Finland for a year now, and there has always been problems to get the interior to heat up. The heater core and coolant thermostat has both been changed now during my ownership, but still there seems to be some problem with the car. I try to explain (sorry for my bad English), and to know the conditions, we have around -10 to -20 C (14 to -4 F) weathers now outside.
- usually I need to keep the ECC (air conditioning / heater unit) temperature knobs all the way to the red line in the max to get the cabin warm during driving, despite driving for over 30 mins. Despite having the heaters on max (and engine temperature being normal), the AC does not push always hot air to the cabin. Sometimes it does (usually when the engine has warmed up, but after some time, it starts to push a bit cooler air) despite knobs being on max heat. The car probably barely gets into 25 C (77 C) inside despite how long I keep the AC on max heat.
- If I have reached a comfortable temperature in the cabin, if you set the temperature knobs to somewhere around 24-26 C (75-78 F), the AC often starts to blow too cool air, and I have to put it manually to max heat.
- I got an auxiliary fuel heater (Eberspächer) installed to the car, but it also does not heat the interior well - always. It depends of the situation.
--> If I have previously driven a short drive, interior being still a bit chilly, and left the heater knobs to max heat, next morning the auxiliary heater will heat the interior.
--> If I have previously driven a long drive and the car has been warm inside, and I left the heater knobs to max heat, next morning the auxiliary heater will NOT heat the interior well, only very little.
This has been puzzling me for a long time, but I think I have a theory. Please correct me if I am wrong, or if you know what could cause this.
Could it be that the ECC systems interior temperature sensor is broken, giving always much too high temp value to the ECC computer?
Thus the ECC would believe the interior is already warm (when it is not), and thus setting the AC / ECC temp knobs to anywhere below max temp (red line) would often result cold air blowing inside?
Could it be also, that due to false, high temp value told to ECC unit, the system does NOT maintain the max heat even if I have the temp knobs all the way to the max, if the ECC reads that the interior temp would falsely be dangerously hot and thus reducing the warm air flow?
If this theory would be plausible, it would probably also explain why my auxiliary Eberspächer heater warms up the interior only on some mornings - if previously the car has been warm (too warm for the ECC due to faulty sensor), it might have left the flaps/pipes/whatever mechanical system there is inside the dashboard, to colder air position, when I have shut down the car in the previous evening. Thus it would not blow warm air inside next morning.
The car has been on several auto shops for repair, and no one has yet solved this issue.
Anyways, the car heats poorly inside despite new heater core and new engine thermostat, and I refuse to believe this is normal for a Volvo. After all, I believe they are made for harsh winters, not only for endless summer countries...
Sorry for a probably very confusing explanation, hard to explain even in my own language, despite with a foreign one..
All the best!
- Sakari from Finland
