[sambo]

Hi Peter. I have an urestricted rubber hose from the bleeder to my header tank but I haven't run the car for more than 5 mins at idle, so it's hard to say. Have you actually measured the temp of the header tank and compared it to the Commodore? Could it be that you have a metal header tank in the Cobra (better conductor) and plastic in the Commodore, hence the temp difference? Or is the Cobra running hot, fan temps wrong...?