Ok, I've been haivng this problem lately. When I drive first off I notice my temp gage will shoot up to max for about 10 seconds, then go down kindow quick. This happens if I'm going about 50 in 5th gear. Once it does that it seems fine. (temp normal riding well) Now theres another problem, water overflows into the overflow tank, and the cap on the radiator isn't the original, so its not that tight. It builds so much preasure that water will spurt out of the cap, and go into the overflow tank. This happens everyday. I seems like it wont do it unless i'm in 5th trying to gain speed. Any ideas what I can do to ix this or what the problem is? Thanks

edit: I notice this happening because the anoying add coolent buzzer goes off.

 

take the cap to a parts store or auto shop and have it tested, the pressure spring may be weak allowing the coolant to go out of the system.

if it is what i am thinking, save your pennies, if the cap tests ok then likely you have a bad compression o-ring. do a search for "bubble test".

 

Thank You