Originally Posted by DayGlo
Could be a radiator cap... if it doesn't seal, the cooling system can't become pressurized. The coolant will then boil instead of staying liquid, causing all sorts of fun stuff. I'd replace the cap just in case - it's cheap, and as easy as it gets.
I have the leaky thermostat housing problem.
The leak started about March of this year.
I partially unscrewed the radiator cap and taped
it in that position. I now do not run ANY pressure
and the leak has stopped. My MSD DashHawk
says 175-185F operating range with a 180F
thermostat installed. Water boils at 212F. A
temp I never see on the gauge. And I run her hard and
fast daily. The level has stayed the same and
the temperature is the same as normal even with
100F plus daytime temps.
I really do not think it was the Radiator Cap.
The root of the problem needs to be discovered.
Wait till it rears its ugly head again and diagnose
it or have it diagnosed properly.
ps the overflow coolant tank caps for the S197s are not cheap
I guess Mr DayGlo was just guessing and not basing his
responses from actual experience with the S197 Mustang.