V70 Expansion tank coolant problem

[erikv11]

That's good news!

[rspi]

Awesome! Good to see that you don't have a bad head gasket. Those caps are strange.

[jimmy57]

I would idle the car in P , and without the reservoir cap, i.e cap OFF.
Once the temp needle reaches 3 0'clock, engine idling check the coolant level, it may take up to an hour of idling, and several thermostat cycle for the coolant to stabilize. The stable level is above MIN, below the middle of MAX - MIN.

This is a great way to get air pockets out but with one suggestion: turn on A/C.
Starting with some 96 models and effective with all 1998 and later models the cooling fan on temp was raised. On these the coolant will boil with cap off before coolant temp is high enough for engine control module to turn on fan. A/C will make fan run due to A/C pressure and avoid a false indication of possible head gasket trouble. The coolant boiling for this reason can send a plume of coolant out of open tank just like a head gasket breach.

[Cp1024]

Bubbles means air somewhere in the coolant system.
Does the V70 have an air release bleed screw fitted on the lower radiator hose as the V40's do.
Was your heater on full when you topped up the system.
Wise especially if the coolant was very low when the warning light showed.

these cars dont have heater core shut off valves, why run heater?

[FlyingVolvo]

Damn... 8 year thread resurrect.

You are right though, that the heater core always has a flow of coolant, regardless of temperature settings. Changing the air to heat will have no effect on purging air from the cooling system.

[abscate]

We shall end no thread, before its time...thanks Ed.