Right, at the risk of sounding really stupid i have tred your test and
think I (not the car) failed.
1. I put the heaters on full blast on hot
2. I took the header tank cap off and made sure the coolant was at max
3. I sat the car at 6k rpm until it reached 70'c
(well i had my mrs do that while i watched, the only prodlem was i
couldnt here the fan above the engine noise)
4. I told her to stop reving the engine at 70'c
5. I heard the fan already at full tilt
6. I watched as the water swelled out of the header tand and all over
Now i thought that no matter what i did with the heater, water would
come out of the tank if the cap wasnt on.
The header tank (im sure you are familier) is in two halves, the
return on one side and the fill on the other.
From the word go the return had what i would call bubbles in it, from
the force of the water being returned to it into such a small space.
The fill never had any bubbles in it until all the water came out,
which i think was all from the return anyway.
So, as i am clearly very lame, can you please post detailed
instructions on how to do this test?
Should i have left the car on idle to reach temp?
should i have stopped reving at lower temp?
Should the water stay in the tank no matter what is wrong with the
One final thing, if it is the gasket, wouldnt the coolant temp be high
all the time? The temp sits at a very low 70'c all the time, the fan
very rarely kicks in at all, except if you have been moterway driving
and suddenly come to a stand still and even then it only comes on for
a few secs before going off.
Thanks again. (sorry to be a pain)