I have 1999 Volvo S80 T6. Recently I noticed the coolant is "boiling" in the expansion tank after a short trip.
The coolant gauge is in the middle of its range(normal). Please, who knows give me a clue. The shop mechanic did flush the radiator and says it works OK.

 

Cooling fan working ok?

Has the recall on the fan been done?

 

Yes the fan is working, I can see it after the trip... I can't say if it starts at the right time. Might it be that it starts cooling the engine too late?
I'd like to know a few things. How to check the thermostat for opening, and how to bleed the air if these are possible causes.
Could you please provide the access hints!

Thanks a Ton

 

The system will bleed all by itself. It might take about 8-10 miles but since it is a closed system it will bleed itself.

You have to see what setup you have.
Is your thermostat in the front of the engine by the upper hose at the engine?
If not then it will be on the front of the engine by the timing belt.

You can remove it and make sure it isn't broke.

You can also put it in a cup of hot water and make sure it opens. It should open at 180 or so.