ka runs hotter at highway speeds!

[nicks13chandler]

i just put a ka24de in my s13 hatch. when i first drove it it overheated halfway down my road. i replaced the water pump, thermostat and when i took the intake manifold off i realized there was a kinked coolant hose that ran right to the thermostat. so i replaced that hose too and made sure it wasnt kinked after installed. i drove the car twice since then and normal driving around it stays right at half, when i get on the highway the temp gauge starts to creep up towards H. even when i get off the highway when it heats up a bar or 2 on the gauge it goes right back down. i compression tested it, came back 150 in all cylinders also did a leak down test and it passed. the only thing i can think of is that the coolant needs to be burped. was wondering if anything else could be wrong so i can get it fixed asap. also would it still be a head gasket if the test came back 150 in all cylinders? new to nissans and 240sx's wasnt sure if theyre different from the usual cars in any way. any advice would help thank you.

[nicks13chandler]

also just to clear things up when i first drove the car i didnt let it get to H i turned it off 2 bars below. and i also replaced the coolant temp sensor.

[todd5854]

Compression PSI for a KA24DE motor I think is supposed to be 180 - 195 but I could be wrong. It's up there. But consistency in all 4 cylinders is important too.

Park your car on a hill in such a way that the radiator cap is the highest point. Fill a funnel up with coolant, on the radiator hole, then start the car. Squeeze the radiator hoses until excess air comes out. Also do this to the heater core hoses (Behind EGR on intake manifold side).

Also, your thermostat should have a bleeder valve on it. A little stupid piece of metal that goes through the hole.. be sure this is pointing at the 12:00 position; facing up top.

[rwtf]

yeah compression is supposed to be around 180-190, but 150 is the FSM minimum. One of my old coupes had 150 across the board and it felt like it had no power at all.

[todd5854]

I had a car which needed a new headgasket and rings so bad that it could barely make it up my driveway.... '84 AE86 with the 4AC motor hahaha. I like my S-Chassis better

[project-c2]

Head gasket? Block test. Quicky, when the car is cold. Start it up and rev it couple times then shut off. Check your radiator hoses and see if pressure built up in the cooling system. If it did, possible head gasket.

[ka4life87]

Does it have the factory belt driven fan or electric fans? Common mistake people do with electric fans is install a pusher fan on the radiator facing the front of the car which at highway speeds air is unable to get through since fan is forcing air forward, then at idle it cools down since air flow from front is not existent

[future]

Really low compression

And are you still running your clutch fan?

[todd5854]

Does it have the factory belt driven fan or electric fans? Common mistake people do with electric fans is install a pusher fan on the radiator facing the front of the car which at highway speeds air is unable to get through since fan is forcing air forward, then at idle it cools down since air flow from front is not existent

Good point here, when I bought my first 240 the idiot put the fans on backwards.

When you rev really high does the temp gauge go up too?