I have a 90 da with an automatic to 5 speed swap and a b18c. I just replaced the thermostat. and flushed the radiator with a hose. i have my fans hardwired so they are constantly running and i checked they are blowing the right direction. The car over heats when im on the highway after driving for about 20 min at around 65 mph. The temp gauge jumps to the red so i put it neutral and cost for about 30 seconds and its back to normal, start accelerating again and it will over heat in a min or two. It has done this in 45 degree rainy weather and when it was 65 degrees sunny. I cant figure out whats wrong with it. the motor that was originally in the car had a blown head gasket so im sure the radiator had some gunk in it i flushed it with a garden hose befores i put the radiator back in the car could this of still messed anything up? Any suggestions please?
also the heat inside the car never really gets that warm. Dont know if its linked to my other problem.
There might be air in the coolant system. Bleed the coolant and see if that fixes it. My car pretty much had the same problem and bled the system and it was fine. Thats just a suggestion.
are you losing any coolant AT ALL?
There is a pipe under the intake manifold that delivers fresh coolant to the water pump. I have seen these get filled up with crap and clog, thus not delivering sufficient water flow. Also would not hurt to check the water pump. To me it sounds like you have something plugging the path of coolant flow, especially considering you are getting no heat in the cabin.
no I’m not losing any coolant. I’m gonna try to bleed the system tomorow
and go from there. Thanks for all the help. I’ll keep you updated
Yep, try bleeding it. Could be a bad water pump?
why is the fan hardwired? i’ve heard of that causing these symptoms
btw, if the engine coolant is at operating temp, and where it should be, and you’re not blowing hot air in the cabin, heater core is clogged. or heater valve is stuck/ cable is broken. however, it won’t cause overheating