V70 Turbo - Overheating

[londonboards]

Just to conclude ...

Yes the thermostat was faulty. It was staying closed. Replaced it and all is well except ...

When I started the engine again, water temperature gauge would not move off the cold position. I thought the sensor might have failed. I checked it with an OHM meter and it was fine.

Finally did a ScanTools check with my £15 ODBC reader and found an engine overheat code up. I reset the code and the water temperature gauge started working normally immediately.

All good. Thanks for your replies.

[Clan]

Originally Posted by londonboards

All of a sudden ...

Engine temp has started to go into the red and warning message comes saying high engine temperature and the fan comes on.

It is possible to reduce engine temperature by running the interior heating system on full blast (old skool trick) and when doing this, the engine temp gauge goes back to the regular mid temp level (12 o'clock position).

On inspecting the engine after it goes into overheat, the water reservoir and hoses do not feel too hot. There is no boiling.

When you slowly open the water reservoir cap when hot, the water fills up and overflows.

Is this a water pump issue or a thermostat?

How much does it cost for a water pump replacement?

I would fit a new thermostat then a coolant temperature sensor first . coolant rising up the bottle is not unusual when you take the cap off when hot . when it is hot and the engine fan is running hard can you feel lots of hot air being blown over the engine from the radiator ?