ok the motor runs perfect can ride around all day in stop and go traffic but prolonged driving causes the motor to over heat like after about an hour of steady 3000 rpm driving on the highway doing 65 the motor heats up and I have to stop but I dont have to turn it off in idle it cools down. this is mysterious to me can anyone give me an idea before taking it in?

 

no thermostat? that will do it...bad radiator cap will do it too...obviously you're fans are working, because in stop and go traffic when you're stopped its cooling it down, therefore NOT overheating. Had this on my KA... its probably one of the two.

 

thanks man I will try the cap thermostat is there

 

If the coolant dosen't spend enough time in the radiator, it can't get rid of it's heat. The thermostat slows down the flow quite a bit. The cooling system was designed by some clever peeps.

Also the engine has to heat up quickly to start burning off water that is a by-product of combustion. You will get sludge build-up if you run too cool all the time.

 

Are you getting any bubbling from the overflow tank when you shut the car off? If so you have air trapped in your cooling system. Have you changed your coolant lately? radiator? hoses? This was my problem. Whatever it is...get it taken care of...don't loose a $3000 SR install over a <$300 radiator, fan setup.

 

i used to have the exact same problem. turned out to be a shitty stock replacement KA radiator.

 

ok thermostat gone new koyo radiator and cap lines all good no leaking but water still boiling ordered a s14 water pump to replace the old so that should pretty much be everything thanks for the tips

 

hey Drifting DJ? thats my old HICAS right? sweet to see u have it running w/SR.

 

hey i had the same problem to the t i have ka thow but my problem was the actual temp sending unit it had a little corosion build up and it would read right at all if i were u get a heat gun go drive ur car and then use the gun on the hoses and all over the radiator if the hot hose is about 200 or 190 and the cold side is 160 or so ur fine i did the same thing changed cap waterpump thermostat hoses flushed the antifreeze a million times it beat me up for about 2 weeks now if u have straight antifreeze u will overheat also i do a 60 per water and 40 antifreeze water disipates heat better