JimmyHat

ok here goes, I have a 93 240sx KA24 twin cam. I have replaced the water pump, thermostat, fan clutch and filled the radiator up. Now when im at idle the car heats up and heats up pretty quickly. BUT as I start to go down the road the temp drops down to normal
I hard wired the elctric fan thats sits on the radiator so its always on when the car is on? Im stumped! I have tried to birp the system but same result. Now, when the car heats up almost to the top but before the nedel reaches H it starts to puff white smoke but goes away when it cools down and there is NO power loss. PLEASE HELP!

truffle_shuffle!

Bad Radiator? Bad Head gasket... I'd do a radiator flush.. or get a new one with out the plastic endtanks if you haven't already upgraded. Just take it logically its either radiator or head gasket.

HondaCRX

Air in your cooling system. open the cap and start the car let it warm up and add water. my friend had this problem.

RubberBerner

Air in the system will heat up very rapidly, a headgasket that would cause heating up that quickly will have contaminants in the water (from the oil), make sure if the fan is on the back of the radiator, that its pulling, and pushing if its on the front. if a fan is pushing on the back of the radiator, its just pushing the hot air from your engine bay right into your radiator.

JimmyHat

done all that. Found that after I let the car sit over night I came out and worked on the car and one last time I burped the system it was fine? I drove the car all over the place and on my way home it did it again. I get it home and look under the hood, there was coolant all over the place. I found that it was the new water pump that was bad because water was comming out the hole in the bottom of the pump so I replaced the pump and now im back to needing to burp the system.. Its a endless cycle I tell you.

HondaCRX

damn that sucks. i need a new pump too. after driving my car is gets really piss slow but the temp does not go over half. So i thinks its my pump. Man 240 suck lol

Durdan

i bet you wired that electric fan backwards and now it and the mech fan are fighting to draw air through the radiator. if its hot when sitting, but cool when moving, its obviously an airflow problem. check your fans.

JimmyHat

fans are good. I checked the polarity and its all correct. the air flow is correct. I need to bleed the air out again. I will do this tonight. I will post up the details later.

J-Dizzle

water temp sensor? replace that , i had the same issues on my hatchback a couple of months ago, i had new water pump and thermo put in and then i had the same problems, replaced water temp sensor and lossen the little bolt on the top coolant housing (follow top radiator hose) while running release some air built up , hope this helps

jason