[Saturn 5]

You probably have a very small leak that only goes under pressure. Radweld may be worth trying, however I have no experience of it so see what other people say. That would explain why the temperatures hotter also.

[IPAddis]

Agreed about the slight water leak but I wouldn't advise trying RadWeld. It can block the narrow water ways and increase the water pressure until something else blows up (sometimes the water pump)! Ian A Griff 500

[edward]

Yeah - even the dealer that sold me the car coughed up for a new rad vs. my idea of using radweld