OVERHEATING 95 240SX

[vjuice602]

Hi every one i have a problem with my cooling system in my 1995 240sx
Heres what ive done
New radiator. Rad cap, thermostat and water pump

It over heats with thermostat on i replaced it twice... No smoke from exhaust bled it like 15 times wt could the problem be, mechanic said headgasket bt i dnt see smoke from exhaust, oil and coolant look regular... Only over heats with thermostat on, so im drivin it without.. Any advice would be AWESOME

[Morph]

When you say thermostat do you mean heat or ac?

What was the bleeding process you used?

[vjuice602]

i opened the bleeder screw then put a cone on the radiator filled with coolant let car run and i had heater on, i also jacked up the car, would you if thats the correct way? the mechanic said it was a headgasket but im not conviced.

[ricebike]

When you say thermostat ...

Morph, from the original post, he's trying to say that it overheats when he has the t-stat installed

when he took it out, it's not overheating...

[Morph]

Sounds like you did bleed it properly, how long did you let it run? Last time I had to bleed my whole system it took about 20+ min.

Few questions
Are you loosing coolant?
What are your compression test numbers?
Was the jiggle valve at the top when you installed the T-stat?

Thanks for the translation rice lol

[vjuice602]

Sounds like you did bleed it properly, how long did you let it run? Last time I had to bleed my whole system it took about 20+ min.

Few questions
Are you loosing coolant?
What are your compression test numbers?
Was the jiggle valve at the top when you installed the T-stat?

Thanks for the translation rice lol

i must have done it 20+ times for 10 min each

and yea i am it comes out the coolant reservoir
and i have not done a compression test how do you do those??
and for the thermostat position i can honestly say i didnt think about that

[vjuice602]

Sounds like you did bleed it properly, how long did you let it run? Last time I had to bleed my whole system it took about 20+ min.

Few questions
Are you loosing coolant?
What are your compression test numbers?
Was the jiggle valve at the top when you installed the T-stat?

Thanks for the translation rice lol

i must have done it 20+ times for 10 min each

and yea i am it comes out the coolant reservoir
and i have not done a compression test how do you do those??
and for the thermostat position i can honestly say i didnt think about that

[Morph]

First if i were you would be to do a compression test. You can rent them at Autozone or O'Rileys whatever you have in your area.

This is my process for compression testing. Start your car let it run for a few min to "warm" it up.
Undo your gas cap and take out your fuel pump fuse.
Start the car, this will clear out the built up fuel from the lines, it should sorta start/die in a few moments. Remove the 1st spark plug and thread in the compression tester.
Start cranking I let it crank 3-5 times and write down what the number is.
Do this for each cylinder and compare the results.

If those come back good then try bleeding it again. Im willing to bet your not doing it long enough. After 10min with mine it was still putting out bubbles.

Your thermostat doesnt open right away and you could/ probally do have some air hiding behind it. If i were you i would get a funnel and fit it in the radaitor neck( use some tape to get a tight water tight seal) and run it for at least 30 min.

[placham]

What about thermostatic clutch for the fan, is it any good?
Grab each rad hose, when car is warm(at otp temp) if t-stat is working both hoses should feel about the same to the touch. If one is hot and other cold than t-stat didnt open up or is bad.
How sure are you that your gauge is reading right temp, did u use hand held temp gun. I wouldnt be chasing head gasket or compression test, with out checking the basics first.
And please use OEM Nissan parts, hate seeing people use Chinese made junk.

[vjuice602]

First if i were you would be to do a compression test. You can rent them at Autozone or O'Rileys whatever you have in your area.

This is my process for compression testing. Start your car let it run for a few min to "warm" it up.
Undo your gas cap and take out your fuel pump fuse.
Start the car, this will clear out the built up fuel from the lines, it should sorta start/die in a few moments. Remove the 1st spark plug and thread in the compression tester.
Start cranking I let it crank 3-5 times and write down what the number is.
Do this for each cylinder and compare the results.

If those come back good then try bleeding it again. Im willing to bet your not doing it long enough. After 10min with mine it was still putting out bubbles.

Your thermostat doesnt open right away and you could/ probally do have some air hiding behind it. If i were you i would get a funnel and fit it in the radaitor neck( use some tape to get a tight water tight seal) and run it for at least 30 min.

yea il prob try that it gets hot then drops after a while

[vjuice602]

What about thermostatic clutch for the fan, is it any good?
Grab each rad hose, when car is warm(at otp temp) if t-stat is working both hoses should feel about the same to the touch. If one is hot and other cold than t-stat didnt open up or is bad.
How sure are you that your gauge is reading right temp, did u use hand held temp gun. I wouldnt be chasing head gasket or compression test, with out checking the basics first.
And please use OEM Nissan parts, hate seeing people use Chinese made junk.

yea only my top hose is really hot and my lower one is cold, do you think its the thermostat?

[placham]

and let me guess your gauge is showing hot right? Buy or rent a temp gun and verify gauge is showing correct temp.
Or better yet get a replacement gauge temp sender, s*** you replaced like all cooling components, whats a 20 dollar part.
Here: http://www.courtesyparts.com/25080y-eng ... 35051.html

If car is running fine and your not loosing coolant, I wouldnt mess with it.
Cause t-stat might be working fine but your gauge or temp sender is FUBARed.
Cause t-stat should open around ~180F or so, thats when both hoses should be equally warm/hot.

You can also verify gauge if you have OBD-I or II software or scan tool like Snap-on Mt2500 or such, or access to CONSUL Nissan code reader/diagnostic scanner. Just check what ECU is seeing for temp and what gauge is reading.

And I bleed mine same way, jack up front end, start car, run heat at max and fan high, top off rad, let run with rad cap off for like 15min. Take a drive, let it cool off, recheck coolant level and adjust if necessary.

I had a time where a diesel semi had, bad h-gasket, failed between compression(firing ring) and coolant passage. It would bust all rad hoses, run out off coolant, over pressurize coolant reservoir, this would happen every few weeks. Verified it by disabling water pump (removed belt) ran engine and had bubbles in coolant, dead give away something was wrong. On compression stroke it would build up compression into cooling system, more than it was designed to hold.

[LoserCard]

I have one question for you... which direction did you install the thermostat? The springy side should be in the block. The bleeder valve (if equip) should be on the top. And the whole bleeding process takes forever. So even if you think you did it right, you might not have.

[vjuice602]

I have one question for you... which direction did you install the thermostat? The springy side should be in the block. The bleeder valve (if equip) should be on the top. And the whole bleeding process takes forever. So even if you think you did it right, you might not have.

i put it the therm the right way as for the bleeder valve i am not sure maybe thats where it went wrong?

[vjuice602]

[quote="placham"]and let me guess your gauge is showing hot right? Buy or rent a temp gun and verify gauge is showing correct temp.
Or better yet get a replacement gauge temp sender, s*** you replaced like all cooling components, whats a 20 dollar part.
Here: http://www.courtesyparts.com/25080y-eng ... 35051.html

If car is running fine and your not loosing coolant, I wouldnt mess with it.
Cause t-stat might be working fine but your gauge or temp sender is FUBARed.
Cause t-stat should open around ~180F or so, thats when both hoses should be equally warm/ho

i do loose coolant through my coolant reservoir it starts to over flow and boils

[vjuice602]

ok heres what is happeing

installed new radiator, water pump, thermostat, rad cap, and bled it a few times

car runs fine without thermostat

with thermostat car over heats then temp goes down, coolant starts flowing through the coolant reservoir and it boils as well

[vjuice602]

i am not sure of what position i put my thermostat i will try toput it back on with the little valve on top if that doesnt work i will prob try to bled a few more times then do a compresion test.

[placham]

ok heres what is happeing
installed new radiator, water pump, thermostat, rad cap, and bled it a few times
car runs fine without thermostat
with thermostat car over heats then temp goes down, coolant starts flowing through the coolant reservoir and it boils as well

This doesnt smell right, and you didnt mention it overflowing earlier.

T-stat should be stamped with "TOP" thats the only way it goes in, at least Nissan t-stats are stamped.

[vjuice602]

yea thats y i am so frustrated about this but im going to try and install the thermostat with the valve on top does that really make a difference
?????

[placham]

Do you think they would go through all that trouble stamping that on there???????
Dont try to reinvent the wheel, just do it like it supposed to be

http://www.nicoclub.com/FSM/240sx/1995/LC.pdf page #8 , diagram# SLC955A that shows T-stat, what does it say by it?

[vjuice602]

Do you think they would go through all that trouble stamping that on there???????
Dont try to reinvent the wheel, just do it like it supposed to be

http://www.nicoclub.com/FSM/240sx/1995/LC.pdf page #8 , diagram# SLC955A that shows T-stat, what does it say by it?

OH WOW THEY DO SPECIFY TO PUT IT ON TOP THIS ACTUALLY GIVES ME SOME HOPE THANK YOU I WILL TRY MAYBE TOMOROW AND SEE WHAT HAPPENS THNKS AGAIN

[vjuice602]

Hello guys bad new i tried thermostat making sure its in correct positionand it still over heats! if this really is my headgasket like my mechanic said wouldnt i be loosing coolant?

[biggie]

Have you tried a different Thermo? Especially use OEM. Sounds like it is overheating due the the Thermo not opening until a too high of temp is reached.

[vjuice602]

i bought 2 new ones from auto zone..

[vjuice602]

they werent OEM thought

[biggie]

Many I know and myself only use OEM due to having issues with aftermarket thermos. But I wouldn't figure that 2 in a row would be bad. Still sounds like they were sticking somehow.

[vjuice602]

im going to go buy one..... my mechanic said it was a headgasket could he be right?? im not loosing coolant?

[biggie]

im going to go buy one..... my mechanic said it was a headgasket could he be right?? im not loosing coolant?

Could be, but I'd try all the cheaper options first.

HG could just barely be blown to where it just pressurizes the coolant to make it overheat. But usually that would get worse while driving and the temp wouldn't randomly drop.

[vjuice602]

yea my car is fine without t-stat but with it over heats temp goes up then 20 sec later is drops then i have my coolant reservior boiling and over flowing I REALLY NEED HELP WITH THIS

[2.4Loflove]

I know it takes me a long time to bleed my KA24DE. My whole cooling system has been replaced and I recently swapped out my coolant and it overheated on me after bleeding. I let the engine cool and went through the bleed procedure again and it was fine. I don't know how the bleed process differs on an S14 but you should have it to where your bleed screw and rad cap are the highest points to get those bubbles out! Biggie has a point ..... let your engine overheat too often and you will have some big problems on your hands.