ok well i'm running to hot, i have a micra rad on the car and if i run the fan it blows cold air and the rad even cool yet the water comming out is still very hot, if i stop the fan the rad quckly warms up

do you think i need a bette rad ?

edit nissan 1.8t

[Edited on 11/7/06 by graememk]

what engine you running

what engine you running

It sounds like a water flow problem.

If you turn the fan off the heat "appears" in the rad probably by conduction through the hoses etc.

But when you switch the fan on this removes the heat gain your getting through conduction thus appearing cold.

I'd look at how your hoses are connected and if there could be any air locks.

check the stat and as said, check the rad. also check all the hoses lead so as the header is at the top so the air can get out. I had same problem with my xr2, the heaters blew hot, the rad got hot, but would over heat. turned out some "muppet" had used "rad weld" to fix a leak and it had actually sealed the stat shut! took it out and just ran with out a stat being as its summer anyway. Will just put a new one in my new engine build.

get a cheap digital laser thermometer they are dirt cheap and then you will know exactly what temp the engine block ,stat top hose etc

The original Micra rad fan actually sucks air through the rad not blows (have I read your post wrong, or have you fitted an aftermarket fan?)

A couple of things you could do, if you haven't already;

1 - Fit a manual over-ride switch for the fan.
2 - Add a bottle of water wetter to your coolant.
3 - Duct ALL the air entering your nosecone through your rad.

HTH
Phil

It certainly does sound as if there is an airlock in the system. I remember when I screwed my C.......m together (sorry for the dirty word) it took several goes before all the air had been removed from the system. It appeared to be full of coolant but it still boiled. One other point not already mentioned is to make sure the radiator is fully boxed in so that all the air coming in through the grille has to pass through the rad.

Let us know how you get on.

Cheers

John

Caterham isn't a dirty word on here. At least not to most of the forum members.

Phil

hello Graeme,
just to clarify, is it the rad fan or the heater fan that is blowing cold ??

Cheers Andrew