Overheating 240

[DAGO88]

i have a 91 240sx with the ka24de. the dam thing keeps overheating. ive replaced the thermostat and the waterpump, and put a pressure tester on it and it held pressure just fine for 2 hours. i cant figure it out and neither can the nissan master tech i work with. it still has the electric fan and the belt driven fan. any ideas?????

[Boosted_s13]

Uuummmmm your head gasket???

[accord_swaggin]

Isnt that a problem with all 240 motors? :tardthink:

[Mitchapalooza]

You havent check out this issue on the 240Sx forums?
No Engine codes? If you replaced the Water Pump & thermostat then either its a sensor gone bad or Indeed an old Head gasket. Had a buddy the had a Northsar V8 that was over heating & he had worn Head gaskets how its really connected to the overheating im still unsure till this day. Are you running full Coolant or 50/50? How old is your Radiator?

[DAGO88]

The pressure test should have shown if there was leaks of any kind, head, head gasket. The radiator is new also. Ive looked on 240 forums and have found nuthing.

[Boosted_s13]

Most likely your head gasket.. I've had several 240's and I hate the ka.. but I would check to see if its not a faulty temperature sensor first... When a gasket blows, with ka's, they can be tricky because not all times does the leak show or respond properly on leak/pressure test, its happened twice to a buddy of mine

[A.M.O.G.]

Before you look into anything like a head gasket or something bigger, please make sure you bleed the coolant system. This step is usually overlooked by many people that replace radiators and water pumps and could be your only issue. Just saying, it does not cost anything, and takes only about 10 minutes to do, and 9 of those minutes is just waiting till the engine warms up. just my 2 cents :-)

[DAGO88]

Well i got it figured out yesterday. I feel like a moron cause it was sumthin so dam simple but i just didnt even think about it. It was the dam radiator cap. I feel like a jackass but now that thats out of the way i can get on with hookin it up

[SKUNK]

Well i got it figured out yesterday. I feel like a moron cause it was sumthin so dam simple but i just didnt even think about it. It was the dam radiator cap. I feel like a jackass but now that thats out of the way i can get on with hookin it up


Could of just swaped it with a B18C and problems fixed :D
















































jk.. lol
Glad you got it. Sometimes we all over look the small things. :woohoo:

[Corey_EF]

I would of never guessed lmfao

[DAGO88]

Yea i felt like a genious when we pressure tested the cap and it leaked as fast as i could pump it. Thanks for the guesses though. A b18 was a good thought though. Haha

[zaquanh]

Isnt that a problem with all 240 motors? :tardthink:

no

Uuummmmm your head gasket???



do a leak down test and compression



have you check the coolant temp sensor? the one for the ecu not for the gauge?


and how long does it take after you start it to overheat. like do you start it then it just overheats or take a couple minutes?


yes bleed the system but it should cause you to overheat at start up just because of air , you can run a motor with out an radiator for some time..



what kind of cooling system do you have?

stock?