Overheating engine

[cameron]

Having lent my friend my van for a week,it's returned with a overheating engine,for some reason the fan hasn't kicked in nd the expansion tank is still full so I'm assuming the radiator is fine nd it's just the fan not coming on that has caused this?is there anything else that could also lead to the overheating?

[discipleofsketch]

Other reasons an engine might overheat:-
- thermostat not opening
- airlocks
- blocked radiator or hoses
- failed water pump

The fan only needs to come on when the temp is already very high

[cameron]

Thanks for the reply,I've just had a new interior put In nd now can't get to the engine bay so il have to get the grinder out to check the coolant level but having checked expansion tank is warm therefore does that lean towards coolant level being low in header tank and using the extra water in the expansion tank?

[R0B]

Who on earth put an interior in that stops you opening the engine lid.Thats just plain stupid.

[cameron]

I think I've found the problem,there was a pin sizeish hole in the top of the expansion tank which as it's pressurised was leaking through this and therefore loosing the coolant at quite a rate .
Hope this is it,I'm going to replace this,what's the easiest way of bleeding the system?

[discipleofsketch]

This seems to be the favoured method (though also the noisiest!):-

http://www.brick-yard.co.uk/forum/bleed ... 29710.html" onclick="window.open(this.href);return false;