[gjkrv8]

Hi Peter,

Giving you were going up in reverse I would have thought the opposite. Anyway, just a quick dumb question - Do you run an overflow tank such that you have a closed system so no air can get in? You mentioned your header tank spat out coolant - was that into your overflow tank?? I would have thought an air bubble would cause it to spit bubbles/air etc.

I found initially with my LS1 my initial overflow tank (a skinny shiny aluminuium one) was too small and it would overflow and then suck air and eventually after a few cycles there would be air in the radiator/engine block and my engine would run hot. My header tank was always going empty.

A cheap $20 plastic overflow bottle did the job and it pretty well doesnt use water now.
I have been stuck in Hoddle Street on a 36 degree day in peak hour and it all works fine now.

Hope you find the problem.

rgds

Gregg