Overheating issue.. help

Hello,

I dont really know the answer to this one so I thought I would ask some people who might know or have expirienced it before.

In the last few days/weeks my tempurature would seem to jump rarely throughout the day to overheat then a few secounds later it would drop down to the middle in a few secounds. I thought it was air bubbles or whatever, just a sensor acting funny. Then it happened more and more frequently to a few times a day then this morning going to work the whole like half an hour drive it was near the overheat bar and never dropped to normal then it got me worried and asking this question as to what is going on. I have rad fluid, all my fluid are good and oil is great.

Could this be a temperature sensor problem or air being trapped in the rad fluid? Whats a way check for the issue or remove the air from the lines or replace the temp sensor?

The rad resovoir was overflowing so what could that mean or does that answer to whats wrong with the issue?

Thx,
Tony

Ya this is a 1992 240sx KA24 DOHC to give some more info on the motor.

Just a thought, could be off, but what is the ratio of coolant/water you’re using? Or do you use premixed? Maybe too much water could encourage boiling once your car’s warmed up?

But that might be idealistic, likely something else is amiss indeed…

Good luck though.

Well I dont think that would be the issue because the rad fluid hasnt been touched in about 2-3 months way before this ever started happening but my fluid is at 60% rad and 40% water or near those numbers since we cant be EXACT.

Im in the office at the moment and ive had someone say it could be my thermo sensor. If it was my water pump it would be a completly different story and I wouldnt have made it to work lol.

Any suggestions or should I get a thermostat and replace it then the next day see how it reacts?

i worked at a rad shop for a long time and theres a few things that u need to know.

When is it overheating? are u parked at an intersection or not moving fatst
When you get up to speed does ur temperature go back down again? or whats ur speed when it overheats?

If it just randomly overheats i would suggest looking at the rad first to make sure its in good condtion and not falling apart. If its good i would make sure that ur fan is working, if thats all good, i would either do a flush and fill, or get a new thermostat and do a flusha and fill. one more thing is make sure that u do have a fan shroud, it can make ur cars temperature go up and down if ur shroud is off… goodluck, i would just narrow it down to what the problem is

alot of the time when i worked at the shop people would come in and their fans wouldnt be working, or their rad is literally falling apart, so just rationalise and come to a conclusion.

Alright to get more info into this conversation i have elctronic fans hooked up to a switch and the car runs fine on the hwy without the fans even being on. The car is still over heating either when im stopped with the fans on or with the car on the hwy doing over 100 with the fans on or off so no matter what the temp doesnt move with fan on or off, being on hwy or on street. Ive just refilled the rad with new fluid a few months ago and everything was working and its great and was working cooler then before. I wouldnt suspect my rad to have any problems.

Ive been driving this car with the electric fans now for over a year and there is no stock shroud on it but the elctric fans do have there own shroud.

Im just soo lost, what would make a car that ran fine within the last few months without anything being changed or upgraded just start to overheat EVEN driving on the hwy with the fans on lol. My only guess which seems logical is that the temp sensor fucked up… My only guess is that the temp is screwed up so that the sensor is on the open position all the time soo all the fluid is being ran through the engine over and over again so the fluid is not sitting in the rad long enough for it to be cooled down. Doesnt that seem logical or realistic? OR it can be on the closed position so no fluid is being ran into the motor, i dont know. Many people are just as lost as I am and keep refering to changing the temp sensor which can be a good start.

What can make the cars rad resovouir overflow and the cars engine temp heat up with it running fine within the last few days.

Any one else can think of an idea?

Also when I get a thermo where is the stock one so I can replace it? Top or bottom hose or us it where the water pump is located.

Fixed, it was a thermostat i got it replaced for anybody who wants to know.

Lock the thread

consider yourself lucky man, it could have been a lot worse.

let that car overheat a few too many times, damage the head gasket and you’re toast.

ohhh another reminder… if your car is overheating and you are fucking lost like i was and bought a thermostat but didnt fix it at all. I had my issue fixed by changing my Rad cap which was very wierd and a cheap fix.

somehow my nismo rad cap lost pressure after having it for only a year not even.