I recently bought an old Volvo V70 (1999) which is required for next weeks planned holiday. Suddenly, since this week the car has a big overheating problem. After driving 80km/h for more than 10 minutes the temperature rises into the red, which results into boiling/cooking of cooling and bubbling air around the cooling system. It seems that all of the cooling is not properly flowing through the system.

The strange thing is we have already replaced the expansion vessel, thermostat and even the radiator. We have filtered the entire cooling system but even after all of this, the problem is still present. What can we do?

Thanks in advance!

 

Check for hydrocarbons in the coolant bottle - indicating a damaged head gasket.

Easiest test is to smell the coolant bottle - a cooling system with hydrocarbons in it gives off a distinctive smell. (you probably would have had to experience blown head gaskets before and noticed that).

Unusual pressure build up, and lots of air bubbles in the bottle with the cap off are two other obvious signs.

It could be possible someone installed a cheap aftermarket water pump during the lifetime on the car where the impeller broke - others have seen that - but I have not. If so the head gasket damage has already been done.