KA24DE overheating did a search nothing sound EXACTLY like mine

[sjrose247]

it is a 1993 240sx witha KA24DE and has an over heating problem. I just replaced teh headgasket, and upper radiator hose (blew both of them from overheating) after i replaced that i checked compression and all is good there, new thermostat, and have bled the system.

After bleeding the system (with teh front end jacked up etc) i drove it and got on it hard since it seemed to have more of a problem under heavy load then constant spped around town. and the temp spiked then came down and i couldnt get it to reproduce it after that. came bac home looked at teh coolant level and it was a little low (in the radiator) so i bled it again filled up some more. The resivoir was high, and about the same ammount of coolant that was "pushed" in there was added to fill the system. thats as far as i have gotten as it started raining last night.

It started that it would overheat after about 3 miles of driving but then about 2 days ago i was able to make it 30 miles on the hwy before it overheated. I watched the gauge and it stay normal for a while then slowly rose. and then preceeded to drive ti the rest of the day almost no problems (slightly raising in temp)

then yesterday i drove 6 miles in town light on acceleration and it overheated.... any ideas cause i have none.

I dont think the head gasket is blown or the head is warped since the engine runs fine all the time and there are no bubblesin the radiator while the engine is running. While running the coolant is flowing through the radiator (i can see it with the cap off) so probably not the water pump. and when removing the cap there is still a good amount of pressure behind it so i would think its holding pressure just fine!

[liquid_cool]

well...there is a step sire that most dont do when installing a headgasket on a KA...its the torque and re-torque part...you must...torque down the gasket and undo the nuts compleatly then re-Torque again...this provides an ample seal...with that said..i have another sugestion for you..

buy a high temp spray style sealent..for headgaskets..this will fill in any slight cracks or voids you may have..hope this helps some..good luck.

[sjrose247]

actually i DID do that, i followed the FSM exactly to what they said i should do!

the spray stuff i didnt use.... but the torque squence i did... however with the compression thing i got around 160 for all of them fluctuation around 5 psi or so... which should be good...

[sjrose247]

OK update the car heats up to almost H after a mile or 2 then it will drop to normal for a while and occasionally raise just to fall again...

Please help

[liquid_cool]

ok..you need to check your temp sensor..ie sending unit ...couse of everything was replaced..thermo/hose/flush/gaskets..then you may actually be running fine..its probly your gauge sending unit malfunctioning and making you go crazy..double check that and get back to us.

[Karateboy88]

It's definitely not from torquing and re-torquing. Micro leak? Nuh-uh.

I would think its the water pump.