Overheating Issue

[xpicer]

Originally Posted by Ali 556

I Was having the same proplem as you...werd over heating and with brand new thermo - water pump - sensor and i was still over heating....

So i Removed/deleted The T-stat and every thing is A-OK...now..

keep in mind that i live in a VERY HOT part of the world..EVERY day the out side temp goes up to 50*C = ~120*F....

And After Deleting the T-Stat...my car never over heat..but it take some time time to go to the normal operting temp...(only 1-2 min later)....

Setup :

2x E-fans (puller) (Auto ON @80*C) And Auto Off @75*C.
2x E-Fans (Pusher's From A Merceds-Benz S500) (not hooked up yet)
STOCK KA Rad.
STOCK EVERY thing else....

So Try And ! The T-stat and see what happen...

Hope This Help,

Regards,

Ali

whoaaa that sure is alot of things , but have you given the though that your radiator migth be clogged inside ??

[drftthatshit]

did anybody think of a fan clutch???????

[ESmorz]

I have a clutch fan and as far as I can tell it is operating perfectly normal.

My car didn't have a thermo for awhile and it would still over heat after about 20 mins of good driving.

[alilvietboi4u]

hey guys. the other day i replaced the water pump, put in a new nissan thermostat. my car will start to overheat on idle. also my upper radiator hose is hot and the bottom is cold. another thing is that my heater core is bad but i never use the heater so there shouldnt be any coolant flowing through the core. any ideas what is the problem? im about to replace my radiator but it looks fine. fan works fine also. its an annoying problem.

[Dirty Habit]

Im having this same problems as everyone else in this thread. Ive changed out thermo, waterpump and on friday Im going to put in a new radiator. Also I have re-routed my lines so that they have deleted the heater all togeather...because I dont have one.
Ill give a heads up if thats what it finally was. Or Ill come back and bitch...

[94eghatch]

Check for hot spots on the radiator. You may have a clogged radiator.

[alilvietboi4u]

Originally Posted by 94eghatch

Check for hot spots on the radiator. You may have a clogged radiator.

no clogged radiator. i ran water through it. flows out the bottom

[DALAZ_68]

if ur radiator isnt clogged, then theres deff a clog somewhere in ur system, this statement is for those who have shanged out there t stat radiator and pump


for those of u with heater...i wonder...did u guys turnt he heater on full blast with the rad cap off once normal temp was reached...? if u didnt theres ur problem...ur system isnt completely bled...


if u looped the lines and have no heater, and over heating...check for pinched lines

also make sure u dont have leaks somewhere...if u didnt clamp something down enough, trust me itll happen

[2_fast_240]

Originally Posted by alilvietboi4u

hey guys. the other day i replaced the water pump, put in a new nissan thermostat. my car will start to overheat on idle. also my upper radiator hose is hot and the bottom is cold. another thing is that my heater core is bad but i never use the heater so there shouldnt be any coolant flowing through the core. any ideas what is the problem? im about to replace my radiator but it looks fine. fan works fine also. its an annoying problem.

If your heater doesnt work. I would go ahead and delete it so you can rule that out.

Also, to all overheaters. When the car is up to operating temp. Check the upper radiator hose to make sure it has pressure.
YOU SHOULD NOT BE ABLE TO COMPLETELY PINCH THE HOSE. I dont care if you bench 500 lbs and eat children for breakfest.
If you can, there is either a leak, or air in the system.

And never rule out a blown headgasket.

[xpertsnowcarver]

if u read what everyone posted so far and diagnosed everything, i guarantee ur problem would be fixed already. it don't matter that its 120f (slightly exaggerating.. don't know wat happens after 110). a properly bleed radiator syst and of course having all radiator system parts in good operating condition will not give u any problems.
now, i had the same exact problem as u. exactly what u say in all ur posts, i had the same exact problem.
i never posted my problem here cus the search found all my answers. diagnosed accordingly from others problems. found my problem. as much as i denied it, and denied it and denied it. it was THE problem i and MOST people have. air in the system.
assuming ur system is using good working parts and ur on a slight incline (driveway incline is enough), u need to pop off the breather screw and let ur car run as hot and long as it has to till water start bubbling and splashing out of the tiny whole. the second water is on the rim of the whole, cap it off immediately. now have water ready to put in ur coolant reservoir. the radiator cap should stay on the whole time and the water level should be right at the cap before u even start (on the slight incline). if theirs air, the coolant pressure will push the air out into the coolant reservior and bubble out. When this happens, keep a constant amount of water in the reservoir (don't over fill it or it will cause further heater for some reasons beyond my understanding). the coolant system will suckin the water to replace the space the air was taking up. plan to spend 30 mins making sure u get everything.
i swear i had to same problem. i also replaced the water pump. it went bad because their was air in the system. the constant raise and fall of temp in the coolant cause a seal along the shaft of the waterpump to break.
i had replaced my thermostat for a nismo. my radiator cap was worn (makes a huge difference. even the slightest crack on the rubber seal will cause and air problem in ur system). don't matter whether u get a jo-shmo 13lb cap at ur local autozone (which i used) or oem, or even nismo 18lb cap or wat have u (switch to the 18 if u want AFTER u correct ur prob using a 13lb., which is wat i did) i don't recommend capping off ur interior heater core if ur having heating problems ever. if ur temp gauge is going up and down, it has circulation, its not clogged. if its reading hot, then suddenly it shows it cooled off after ur punched it, coolant had to have cycled threw. i recommend using all water in ur system and the wetter-water additive (cost 10 bones). i replaced my hoses as well. i recommend keeping on a working thermostat with the breather whole on top. spending 280 for a koyo is worth it especially these days in so cal. its freakin hot right now. im sure i left more details out from my ordeal.

here's a pic of some sludgy syrup krap that i found in replacing my hoses:


if none of wat i said worked, ur still doing something wrong, or find something else that can handle it and has more reliablity.

as far as wat i now have ever since my experience: koyo rad w/ nismo cap and thermo. replaced hoses and pump. water and wetter-water additive. the op. temp is a full length (length between two makings in gauge) lower than factory op. temp. i have no clutch fan. i never use a fan, cus the car handles it perfectly. i have two electric fans that never turn on. the front mounted fan (found on 89-90 240s is the automatic overheat fan the car controls. the rear mounted fan found on 91+ 240's is the electric fan i control.

[Dirty Habit]

Ok. I replaced my thermo, waterpump, temp sensor and now radiator and the bastard still overheats. Well, whats wierd is that the upper hose gets supper hot, but my temp gauge says that the engine is running normal, and I can feel it getting super hot, to the point where its boiling out the burp hole. Temp gauge stll stays between H and C. Anyone have any ideas? can it be the heater hose or maybe the clutch fan??
Thanks.

[Dirty Habit]

Ok Update. It still over heats after a few mins. Ive burped it a few times now. I can feel air going through the top radiator hose, like big bubbles going through it. Pulled open the bleeder tab but nothing went though. WTF.

[DALAZ_68]

did u turn the heater full blast while doing it?

[Dirty Habit]

I dont have A/C or Heat in the car. Heater is looped out of the system.
This is driving me fucking nuts. Ive bled it close to 5 times now since I last flushed it.
I just wanna drive my damn car.

Oh and can someone with an fsm handy please tell me what the name of the plug next to the coolant temp sensor is. Its for gauge, i cant find the name of it...?
Thanks.

[whodaman187]

Is your coolant reservoir cracked, like most? I've heard that you can suck in air through the crack if it is big enough.

[shmiddy]

Originally Posted by Mikey213

What.are.the.cons.of.not.running.a.thermo.though?

car takes longer if ever to reach operating temp leaving the car system in an open loop... shotting lots of gas in the cylinder when its not needed. the gas can then wash of the small amount of oil between the cylinder walls and the rings causing ring wear. or if left in open loop for a long time gas will end up in your crank case diluting the oil, causing oil pressure loss. but that an extream case. damage can also be caused to you cat

[i8yourfwd]

Originally Posted by Dirty Habit

I dont have A/C or Heat in the car. Heater is looped out of the system.
This is driving me fucking nuts. Ive bled it close to 5 times now since I last flushed it.
I just wanna drive my damn car.

Oh and can someone with an fsm handy please tell me what the name of the plug next to the coolant temp sensor is. Its for gauge, i cant find the name of it...?
Thanks.

PhatG20 - 240SX

Here's a downloadable fsm