havent installed the auto thermo switch when i installed the s13 radiator, reason being in 4 weeks its all coming out again for the L series.

Set your thermo fan to cut in at 185C and cutout at 182C and you should have no dramas

180c is normal operating temp

nah not high revs, temps rose in traffic, not driving.
i have an external overflow tank for the radiator that draws coolant out of it if it needs it.

seems ok now, started to rise to 190 but then cooled when turned manual thermo on as well now, so stock fan usually, when it hits 190 i turn thermo on manualy and drops markedly... to 180 almost in 30sec.

Hi, Another cause of overheating if you are running at high revs is water pump cavitation. I had this problem with running sustained high revs for extended periods. The fix was an external pressurised expansion tank, never had a problem after that. But I was right with the seal.

im such a knob, the bypass hole in the water pump was seeping and after a couple of sms to confirm, water pump gone so thats probably why the over heating..... never noticed a loss of coolant though, bizzare?

probably beacuse of the header tank for the radiator recovery system i set up with the n13 radiator.

another water pump installed and had to mod the fan to fit with a power drill and a jig saw, runs close enought to true, only has to last til 13th jan....hopefully and the long drive to L series magic.

i think they made it that way so corrosion eats the housing away before the eating the block.

thanks to all fo r more suggestions, not the water pump front seal, leaking from actual seal i made with rtv, the coolant in the hoising passages seeped down and caused the gap inthe rtv i made the seal of. (taught me to blow out the air in the passages).

could try another cap, just for the low low purchase price

If you have any sign of coolant leaking from the front seal it will be the internal ceramic seal in the water pump which can leak intermittently, that could cause overheating, also check the radiator cap. Hope this is of some help.

Dont get me wrong DD, the A series are a Great design and engine, I was just supprised that the water pump cavity and housing is seperate from the block. form this, after 30 odd years the seal will perish and detiorate, but from a design point of view, it creates the protentail for leaks and problems later on.

If it was part of the block it self, i would see less of an issus for the longevity of the desgin, but then i guess the iron block would rust away in that spot like the inlet water pipe that enters the cavity.