V70 D5 Coolant Problem

[Konda]

Originally Posted by M74

Sounds the same as mine. Do you see a frothing in the expansion tank when the car is revved. It certainly looks like air is being drawn in from somewhere close to the expansion tank.
Other thought was if it was something to do with the water pump drawing in air.

When I was checking the head gasket (running engine without the coolant cap on) there was a lot of frothy return, more so at revs.

Been driving for a few days keeping below 2000rpm and the level has remained at max.

[Hasse53]

I do not see any frothing in the expansion tank, in my son's car.

With a special coolant cap with a hose connected, and then the hose put into a glass of water, I can see that when reeving the engine, pressure in the cooling system falls below atmospheric pressure i.e. it's sucking. Thereof my theory of the engine sucking air past the o-ring in the coolant return pipe during warm-up(sorry for bad grammar).

[uuski]

I’m also having the same coolant problem with my 2011 V70 D3. The coolant level decreases in the expansion tank causing the coolant low level warning. When I unscrew the expansion tank cap the pressure is released and coolant level rises back to normal. Have you found any solution to this problem so far?

[uuski]

Problem solved!

There was a crack in the cylinder head and it was changed. The really strange thing is that the car has been driven only 180 000km! I can't believe how weak these Volvo diesels are!?