coolant test strips to test for exhaust gasses in coolant?

[wil0]

My dad has a 2.0 zetec westfield, when he drives it hard, the coolant system presurises and coolant is forced into the overflow tank, while the engine overheats. Were pretty sure its the headgasket that has a crack in it or something... I said id do it, as ive got nothing else todo at the moment.
apparently there are test strips that can test for exhaust gasses in the coolant? and idea where to get these?
i would go to a garage and get them to test it with a gas analyser, but it only happens when its driven hard, and its hard to spot anyway.
Cheers in advance
Will

[danny_p]

the exhaust sniffers are avalibel in various places, tbh i don't use them  but all they do is look for CO desolved in the coolant

[wil0]

can you link me? i can only find ph based test strips.

[danny_p]

http://cgi.ebay.co.uk/UNIVERSAL-CYLINDER-HEAD-COMBUSTION-LEAK-BLOCK-TESTER_W0QQitemZ180395565856QQcmdZViewItemQQptZUK_Diagnostic_Tools_Equipment?hash=item2a0069e320&_trksid=p3286.c0.m14

[Wayne]

http://cgi.ebay.co.uk/UNIVERSAL-CYLINDER-HEAD-COMBUSTION-LEAK-BLOCK-TESTER_W0QQitemZ180395565856QQcmdZViewItemQQptZUK_Diagnostic_Tools_Equipment?hash=item2a0069e320&_trksid=p3286.c0.m14

I have used and can recommend that kit.

[wil0]

That looks great, thanks very much! it only happens when he cains it, so il get him to go for a drive, then we can try and test it afterwards.hopefully there will be enough exhaust gasses in the system still to get a result, as they wont be present at idle i dont think...
once ive fixed it for him, i might be a little bit close to being allowed to drive it...

[danny_p]

lotus 7 style cars are sods for this, don't be suprised if the head gasket is fine.  they are very fussy animals about how the coolant system is bled, you can get pockets of air hideing, when you have somerevs on it works round to the pump and causes it to cavitate  and stop pumping water round effectivly. result motor suddely gets hot