More overheating issues.

[AnotherZenkiKid]

I have a 95 KA24de in my s14, and been going through a crap ton of over heating issues,
Whenever i drive the car the temp gauge spike well past H then suddenly drops back down after 1-5 minutes then shoots back up again, I also hear bubbling coming from the resevoir as well whenever i drive and when i shut off the car.

I thought it was a blown headgasket...

However this is the parts that gets to me, i check my oilpan to see if i have any leaks and water mixing with the oil, the fluids aren't milky or anything like you would normally see if the headgasket is bad, same when i check the oil cap.
I've also bled the system countless number of times and i have to keep adding coolant every so often as well.

I just replaced the thermostat 2 days ago it ran fine for about an hour then it went back to it's old problems,

Had a new mishimoto radiator put in as well and i wired the fans to where they are on all the time.

haven't done a leakdown or a compression test yet.

any input guys?
and have you guys been through a similar situation?

[Edwin562]

have you properly bleed the system for air bubbles?? also did you position the t-stat properly? there is a small hole that should be on the 12 o clock position.

[AnotherZenkiKid]

yeah i read the write up on here on how to replace it i had the small hole on 12 o clock and i bled it according to the write up,

keep adding water and loosen the bolt until coolant comes out right?

[AnotherZenkiKid]

I followed this write up when replacing my thermostat,

Thermostat Replacement Write-Up : 240sx General Discussion (http://forums.nicoclub.com/thermostat-replacement-write-up-t324954.html)

i also replaced the water pump no less than 1000 miles ago when the problem first occurred.
At that time i replaced the thermostat on it as well.

[Edwin562]

what is your coolant/water mixture??

[Sterlz]

Any leaks? I had a similar problem on an SR, and realized there was a slow leak coming from the heater hoses on the firewall.

Took me a while to realize it was leaking cuz it was just sliding along the wall, instead of just dripping to the floor.

[dawagarage]

have you bled it with the nose of the car elevated to help the air bubbles to rise? also, you could spend a lil bit and get this Ã¥â€*·åÂ�´ãƒ‘ーツ Cooling - POWERED BY MAX (http://www.gtfactory.jp/cms/page.php?11) and never have to worry about bleeding issues again. i have one of those and its a freakin life saver (breather tank)

[AnotherZenkiKid]

i was using the 50/50 pre diluted stuff prestone offers then i changed it to about a 70/30 when i did my thermostat since i bought the advance autozone stuff that you had to mix with distilled water.

and again no leaks from what i see ima go check the walls and see if theres any running down there like your car.

I just ordered a new engine rebuild kit last weekend since this problem was getting outta hand but just wanted to see what was causing all these problems before i put it in.

[sr240sxs14]

does it smoke when you drive it at all??

[Promise Land]

I had a similar condition on my S14 last Fall. I lost a coolant hose and got the engine too hot. I warped my head. The headgasket never leaked into the cylinders, so no mixing in my oil. My car would overheat and bubble. It turns out that the warped head would allow compression from my cylinders (1 and 4) to blow past the gasket into the coolant and over-pressurize it. It was really bizarre and I couldn't figure it out until I took the head to a machine shop for measuring.

Hope this little story helps in some way, or just confuses the issue more. :wiggle:

[AnotherZenkiKid]

i have yet beld the car with the nose jacked up..
my friend told me about doing something like that, ima give it a shot tonight.

also another friend of mine says that their might be clumps of gunk in the cooling system and a proper coolant flush would help out.
Opinions about that?

[AnotherZenkiKid]

ohhhhh i hope its not a warped head...
I have no money to fix that problem atm..

thats a scary thought now hahah lool.'

[boback1]

Have you thought to check if it's a faulty temp sensor. Just saying could be a possibility.

[ultimateirving]

Have you thought to check if it's a faulty temp sensor. Just saying could be a possibility.

this is a good idea, but a faulty CTS might also cause issues with drivability..

[dawagarage]

there could be positives in regards to the coolant system flush but i have only heard of negatives. well, in regards to using chemicals @ least. sometimes the chemicals could dislodge the built up 'gunk' only for it to be lodged elsewhere. if anything i would just flush the sytem with water until the water runs clear. then i would RUN with 9X% distilled water & a coolant additive to give the water better cooling abilities as well as anti-corrosive properties.

[sr240sxs14]

there could be positives in regards to the coolant system flush but i have only heard of negatives. well, in regards to using chemicals @ least. sometimes the chemicals could dislodge the built up 'gunk' only for it to be lodged elsewhere. if anything i would just flush the sytem with water until the water runs clear. then i would RUN with 9X% distilled water & a coolant additive to give the water better cooling abilities as well as anti-corrosive properties.

I have heard the same thing . I have also seen and heard of the chemical additives can cause your water pump to leak soon after the chemical has ran through the system

[Kleistc]

this is a good idea, but a faulty CTS might also cause issues with drivability..

What would these issues consist of? My friend has the same car as OP and his is bubbling and doing the same thing plus a few other issues. Temp guage reads weird and it appers its leaking water under pump very steady. Last night it started misfiring and then later ran out of power and killed from what he explined to me. Just want to fix small issue if there is any rather then just spending the $300 for a new motor.

[fliprayzin240sx]

Fuck fuck fuck...my POS just started overheating and I got an event tomorrow. Since you said you just changed your thermostat, if you bled it properly, it could be a shitty/stuck thermostat too.

[corby_baby]

mishimoto radiator could be the start of your problem. the caps have been known to fail. for every psi the cap holds, should raise the boiling point of the water 5 degrees or so. most people run 12-18psi caps averaging about a 70 degree rise it takes for the water to boil. if the cap is not holding any pressure then you are going to start boiling the coolant at 212 degrees (which if you think about it is really easy to do since our cars run close to that on a daily basis). once you start boiling the water you will never get it cool again until you just shut the car off.

what a cap is suppose to do-----> VIDEO0047.mp4 video by corbeybaby - Photobucket (http://s19.photobucket.com/albums/b187/corbeybaby/?action=view&current=VIDEO0047.mp4)

first start by getting a new cap. next bleed the system properly and make sure all bubbles are out. more than likely your thermostat is still fine. easy way to check is after all the air bubbles are out warm the car up. the bottom hose will not get hot until the thermostat opens. if the bottom hose never gets hot then you either have an air pocket trapped behind the thermostat or the thermostat is simply broke.


i did encounter the same thing as Promise Land up there. combustion gases kept pressurizing the coolant system letting in air and causing my shit to overheat.

[fliprayzin240sx]

Stuck thermostat for me...

[Nesser]

Had this problem about 2 weeks ago. Bad water pump was my problem.

[SLiDe_WaYz]

WHere did you buy your T Stat from ? If its a parts house special im pretty certain thats your problem. Buy a real OEM T stat or a nismo one. Most likely that will fix your problem if you do that and bleed the system properly.

I had your exact same problems a year ago when I had a KA. Went through 4 T stats, bled the system multiple times, added a swirl pot, nothing changed. I tried a Nismo T stat and it made my car run perfect oddly enough.

[fliprayzin240sx]

WHere did you buy your T Stat from ? If its a parts house special im pretty certain thats your problem. Buy a real OEM T stat or a nismo one. Most likely that will fix your problem if you do that and bleed the system properly.

I had your exact same problems a year ago when I had a KA. Went through 4 T stats, bled the system multiple times, added a swirl pot, nothing changed. I tried a Nismo T stat and it made my car run perfect oddly enough.

I got my shit from Napa/Carquest...US made thermostat. I put the first one in around August of last year. Shit just suddenly decide to stay shut last month. Went to get another one from them and drilled out the jiggle valve on top.

[n8RPS13]

mishimoto radiator could be the start of your problem. the caps have been known to fail.



First time I have heard about this. I have had mine for about a year now and I have a 300 HP supercharged KA and have not ever encountered over heating. I think he needs to properly burp his radiator.

Okay dude this way works the BEST! Take a spray bottle like from home depot, cut the bottom off, take some electrical tape and wrap it around the neck where the sprayer screws on, this is so you get a tight fit, next take off your rad cap and push the spray bottle neck in the radiator. Fill up the spray bottle about 1/3 . Turn on the car, squeeze the radiator upper and lower hoses and you will see bubbles come up through the spray bottle. The level of the fluid should lower a little when this happens. Once the car get's to running temp and the t stat opens it should take more of the fluid. Keep adding more fluid as it lowers and keep an eye on your temp guage. This system should only take about ten minutes depending on how much air is in your rad/motor. DO NOT USE THE BLEEDER SCREW WHEN DOING THIS!!!! It will just suck in more air as in will not be the highest point anymore.

[soryu]

i was having the same problem. drive 5 min car starts getting hot just under the H. then comes back down in a minute bubbleing from reservoir. flush cooling system,
replace thermostat,water pump,burp 30min. i can see fluid circulating drive 5 min same thing. this time bubbleing coming from top hose. burp for 20 min with nose raised. drive same thing. i say fuck it open rad cap with hot engine. i used a couple of rags on top of rad cap twist it a little to let some air escape then close it. i did this a couple of times till no air came out while opening lots of steam came out no fluid came out. after all the air came out i filled the radiator back up car not overheating anymore.
i also dropped in a new clutch fan and some water wetter.
car runs at 3rd line above the C.

[thefro526]

I had the same issue a long time ago.

It was a series of faulty thermostats, which resulted in me running without one. I'm not suggesting this be done in long term, but if you've got an event to make, give it a shot. If it works, just ensure that the motor gets to operating temp prior to driving and you're ready to rock. (Again, short term solution.)