overheating issue

[shaun_89]

My g40 keeps overheating. Im sure its got a coolant leak somewhere but i cant find it. I am making sure its always got enough coolant in but its still running between 90 and 110 degrees, so i cant get anywere. I undid the expansion tank yesterday and loads of coolant just leaked all over the floor, couldnt see where it was from, somewere around the back of the block area. Any ideas why it would let all the coolant go like that?

[PeteG40]

if its hot, coolant pressurises so it comes out the top of the tank!

[hayesey]

yeah the coolant will leak out like that if you remove the cap when it's hot, you should never remove the cap till you've let the coolant cool down a bit because it's pressurised when hot. 

So are you having the top the coolant up then?  Look for signs of leaking, you'll normally get a crystally residue where the coolant has been leaking.  It could also be a headgasket failure, a "sniffer" test on the coolant should indicate this, you'll need to take it to a garage who can do one.

[swiftg40]

might be worth checking the gasket on the end of the metal water pipe under the inlet manifold...thats where mine was.