Constant Overheating.....WTF Help

[chrismo240sx]

ok guys i dont know what else to do and im afraid of the big problem it could be.......heres the deal: 93 240sx with ka24de motor.....127,000 miles and going

My cars temperature reading on the inside dash is constantly reading towards Hot.....every few minutes, the needle will rise past the last line beyond the H for Hot then go back down but not in the middle where it should be...it flutters between the middle and the Hot mark then repeats the process every few minutes.

today, i changed the coolant temp sensor, changed the coolant and bled the system to get all the air out, and last week i gave it a tune up.

im down to 2 other sources and one is really not good which i hope isnt and the other is easy and cheap1) Coolant temp sending unit....maybe this is the problem misreading info or something, or...2)Blown Headgasket.....i really hope its not this

i should mention while the gauge reads hot or even past hot....the car does not smoke or sputter. However, the longer i leave it in a gear, the harder it is for the motor to continue reving...it struggles to rev past 5500 rpm and it never use to before all this.(even in 3rd or 4th gear) usually it will rev out all the way to 6500 but not anymore

sorry for the long post but please help me out with this as i am getting scared and worried and losing patience....sorry for the long post but i want to let you all in on all i know!!!

As always, thanks in advance!

[chrismo240sx]

i was just reading....when i bled it, the car was not lifted up in the front which ppl say to do...i will try that tomorow...also, i bought a new thermostat from autozone and they said ir was oem replacement but ive also read that none work unless if its from the dealer? lol....that true?

anyways, any advice or help/tips......thanks again

[motoman399]

sounds to me like you bleed the system wrong. there is a bolt with a sticker next to it that says something like dont open when hot. the bolt is by the temp sensor. take the bolt out and then with the bolt out fill radiator until coolant comes out of the bolt hole. then reinsert the bolt. if that doesnt work you have bigger problems

[motoman399]

i was just reading....when i bled it, the car was not lifted up in the front which ppl say to do...i will try that tomorow...also, i bought a new thermostat from autozone and they said ir was oem replacement but ive also read that none work unless if its from the dealer? lol....that true?

anyways, any advice or help/tips......thanks again

not true. just make sure that the little hole on the thermostat is at the top when you install it

[chrismo240sx]

yupp the little hole was at the top...did that right

i did use the right bleeding valve just not correctly i guess?i know the one your talking about, thats the one i used but i didnt fill it with coolant

i left it open until the car warmed up and then coolant came pouring out...i thought that would get all the air out no?

anyways ill try that tomorow, now do i bleed it with the front of car lifted/raised or flat surface?

[motoman399]

no your way wouldnt work cause when the car is hot the coolant expands. i have never lifted the car in the air to do this. you can try it. but i dont think its necessary

[chrismo240sx]

okay so flat surface should be okay....

one more thing, i gotta fill the bleeder while car is running and cold right? lol

[motoman399]

no open the bleeder and fill the radiator. that will make sure that your entire system is full with no air bubbles. oh and make sure you replace the bleeder bolt and your radiator cap.

[motoman399]

and do it when its cold so you dont burn yourself with coolant like i did lol

[motoman399]

oh and make sure your overflow tank is topped off

[chrismo240sx]

overflow tank is topped off

if i open the bleeder then fill from radiator cap, it would overflow from the radiator cap first before the bleeder i think, idk maybe not we'll see

oh and is it necessary to replace the rad cap and bleeder bolt?

[motoman399]

it always comes out the bleeder first for me. and by replace i mean dont leave them off lol. like put them back on. anyways it sounds like you just need a good bleeding of the system. let me know if it works. i think im a genius lol and i want to know for sure hahaha

[chrismo240sx]

damnit, thats what i thought you meant....silly me anyways, yea ill do all this tomor and have an update as soon as i do it

thanks for the fast help man, appreciate it

[motoman399]

hope i did help lol good luck

[Soravia]

Quickest way to bleed air out is to park the car with then front end lifted about 1 foot above the rear and heat it up.The radiator cap should have a pressure release toggle switch in addition to normal 13lb load spring valve.

Once the car starts to over heat, release the toggle and that will make hot air and coolant flow to the catch can.Once the thing stops flowing, stop the engine and fill up more coolant. Then repeat the step above.This gets out all the air trapped in the system.

[donjuanmon]

ok guys i dont know what else to do and im afraid of the big problem it could be.......heres the deal: 93 240sx with ka24de motor.....127,000 miles and going

My cars temperature reading on the inside dash is constantly reading towards Hot.....every few minutes, the needle will rise past the last line beyond the H for Hot then go back down but not in the middle where it should be...it flutters between the middle and the Hot mark then repeats the process every few minutes.

I had a similar problem last month. To resolve it, air had to be bled out of the system. On top of that, I went ahead and bought a brand new radiator as I discovered that 70% of the old one wasn't being used. Now everything is fine. I really don't think that you've blown a head gasket. Keep us updated!

[BigMACKenzie]

Did you change your thermostat out yet?

[cesarnono13]

ok depending on where you live you really dont need a thermostat at all. i live in southern cali and drive all year with no thermostat. all it does is that i have to wait like 10 minutes in the mornings in winter to have it warm up a bit. but yeah i would suggestto remove thermostat completely and see how it runs after that. if it still overheats then id check the water pump, even if its new some may be defective. good luck and let us know! by the way be really careful with the thermostat housing or water outlet whatever you want to call it because i broke mine and theyre 30 bucks each.... i got pissed! lol good luck, and let the silicone sit for a couple of hours to avoid leaks.

[youngun21a]

Yeah did the same thing no thermostat,and it take about 10 to 15 min to reach normal temp,I even have my dual altima fans of till it reach normal temp then turn them on.Cause if I leave them on it will take long,but yeah try it with no thermostat and see what it does.

[crazeddingo]

Go for cheap first, definitly replace the radiator cap and bleeder bolt. If the Cap is bad it wont be able to hold the presure and it would leak water over to your reservoir. You didnt mention anything about having to refill tank or not. But you did mention correct bleeding so... Careful runing the engine that hot, if your head gasket isnt blown you might just blow it.

[hugesack]

I wouldn't remove your thermostat to mask the overheating problem. You need to figure what the real problem is. Running no thermostat creates hot spots in the head cause the coolant moves too fast to absorb heat. this happens especially on the highway. theres a reason why car makers put them there