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ESmorz
05-17-2008, 02:50 PM
Alright editing this so the new problem is at the top...

When I drive in gas saver mode or let the car idle, it will start to spike and over heat. If I throw some spirited driving in there and rail it, the temp goes down to normal and stays there.

Any ideas?

Sileighty_85
05-17-2008, 04:34 PM
Replace thermo, get a Nismo Thermo.
http://www.thenismoshop.com/ikorb.php?func=catalog&category_id=1159&product_id=266

water pumps dont really go bad just the seals (leaks)

be sure to properly bleed the system too

SleeperSx
05-19-2008, 06:36 AM
Fuck Nizmo Thermo's, There over Priced garbage. Don't waste your money when you can go to the local parts store and get one for around 12-20$ Vs Nismo 80$+.

When running with the radiator cap off and it warms up, Can you see any flow in the radiator at all? If not then its either the thermo is stuck open or the water pump is not pumping. I would start with a thermo stat first and if that doesn/t fix it then move on to the more expensive part. Water pump. You shouldn't have to drive the car for it to get hot. If its going to get hot it will do it at idle. Also don't let it get above 215 degree's or else your going to warp that head and get a blowed head gasket.

mifesto
05-19-2008, 09:08 AM
i can understand its overpriced but why do you say its garbage?

Sileighty_85
05-19-2008, 09:18 AM
Fuck Nizmo Thermo's, There over Priced garbage. Don't waste your money when you can go to the local parts store and get one for around 12-20$ Vs Nismo 80$+.

When running with the radiator cap off and it warms up, Can you see any flow in the radiator at all? If not then its either the thermo is stuck open or the water pump is not pumping. I would start with a thermo stat first and if that doesn/t fix it then move on to the more expensive part. Water pump. You shouldn't have to drive the car for it to get hot. If its going to get hot it will do it at idle. Also don't let it get above 215 degree's or else your going to warp that head and get a blowed head gasket.

If you look at the link i provided this Nismo Thermo is only 50 bucks they had a sale awhile back and got mine for 30 bucks.

I love mine, Before my temp would be around 86-92*C on a hot day
Now with my Nismo Thermo it never goes above 67*C unless I have the A/C running

Anyway..

If the Thermo is stuck open then his engine would not over heat and you would see the water flowing.
If it was stuck closed, (which it probably is or just not opening when it should) then his engine would over heat.

A water pump never stops pushing the coolant unless there is FOD inside the system and some how breaks the shaft or the bades, and the Blades on our water pumps are pretty damn beefy so i doubt that is what happend.

Remove and replace Thermostat
flush coolant
Fill
purge air
Enjoy

SleeperSx
05-19-2008, 09:33 AM
If you look at the link i provided this Nismo Thermo is only 50 bucks they had a sale awhile back and got mine for 30 bucks.

I love mine, Before my temp would be around 86-92*C on a hot day
Now with my Nismo Thermo it never goes above 67*C unless I have the A/C running

Anyway..

If the Thermo is stuck open then his engine would not over heat and you would see the water flowing.
If it was stuck closed, (which it probably is or just not opening when it should) then his engine would over heat.

A water pump never stops pushing the coolant unless there is FOD inside the system and some how breaks the shaft or the bades, and the Blades on our water pumps are pretty damn beefy so i doubt that is what happend.

Remove and replace Thermostat
flush coolant
Fill
purge air
Enjoy


I meant stuck closed. My bad,

As for the thermo, My Rb one is 80$+ I was just throwing it out there. Either way 30-50$ is WAY TOO much.

Why is Nismo garbage? I just don't like any of there products. They seem to have a mis led rep with me.

I was going to buy a clutch slave from them a while back for my Rb trans since I couldn't find a good one. Found out the SAME clutch slave they were selling I could buy at Napa for 16$ Nismo's price 250$ IMO B.S and I will Never Ever Ever give them my business nor recommend them to anyone.

I agree with the water pump also, its not likely its bad, but I have seen a few that is. Thats why I suggested looking for the radiator flowing.

Also the car will overheat if the Thermo is stuck open. Should take a long time for the car to warm up and once it does its possible the radiator can't keep up and will cause it to overheat. But if this is the case you can check it by popping the cap while its cold. There should be NO coolant flowing while cold.

2_fast_240
05-19-2008, 11:25 AM
I agree with screw a nismo thermostat. If it works correctly, then your car will never get up to the proper operating temps. At least thats the way I see it.

And you say it has a "clicky gurgling sound". When exactly do you hear this? Are you sure you dont have any leaks? Does it build up good pressure? You shouldnt be able to squeeze the top radiator hose shut when its warmed up. If so, there is air in there, or you have a leak. And the water pump is bad about leaking around the seal too.

Sileighty_85
05-19-2008, 01:35 PM
I meant stuck closed. My bad,

As for the thermo, My Rb one is 80$+ I was just throwing it out there. Either way 30-50$ is WAY TOO much.

you gotta shop around/research
your RB Thermo- $40 here
http://www.thenismoshop.com/ikorb.php?func=catalog&category_id=3725&product_id=12076



I was going to buy a clutch slave from them a while back for my Rb trans since I couldn't find a good one. Found out the SAME clutch slave they were selling I could buy at Napa for 16$ Nismo's price 250$ IMO B.S and I will Never Ever Ever give them my business nor recommend them to anyone.

its not a question of function but reliablity.
I use the Z32 slave from Napa on my SR and had 2 of them crap out already and im only using a stock clutch, im waiting to buy a Nismo when i get a chance.

I'll pay more for reliabilty.


Also the car will overheat if the Thermo is stuck open. Should take a long time for the car to warm up and once it does its possible the radiator can't keep up and will cause it to overheat. But if this is the case you can check it by popping the cap while its cold. There should be NO coolant flowing while cold.

why would it still over heat if cooler water is still flowing through the engine?
The reason why the engine over heats when the thermo is stuck closed is cuz the water in the engine is not flowing enough so it just chills there and get hotter

thats why lots of ppl pull the thermo out so there engine will run cooler

Mikey213
05-19-2008, 01:56 PM
What.are.the.cons.of.not.running.a.thermo.though?

LA_phantom_240
05-19-2008, 02:04 PM
I'm guessing you're at work and can't use the spacebar?


Anyway, if your engine runs too cool, it can cause premature wear from what I've been told. As the engine gets hot, the metal expands and such, and no expansion equals more wear on certain pieces such as rings. This is all just what I've been told, and I don't have any hard evidence or experience.

Sileighty_85
05-19-2008, 02:16 PM
What.are.the.cons.of.not.running.a.thermo.though?

I'm guessing you're at work and can't use the spacebar?


Nah its one of those:
You know you drive a 240SX when, your space bar breaks and cant afford a new one cuz all your money goes to your car.

J/K Mikey

SleeperSx
05-19-2008, 02:44 PM
you gotta shop around/research
your RB Thermo- $40 here
http://www.thenismoshop.com/ikorb.php?func=catalog&category_id=3725&product_id=12076


its not a question of function but reliablity.
I use the Z32 slave from Napa on my SR and had 2 of them crap out already and im only using a stock clutch, im waiting to buy a Nismo when i get a chance.

I'll pay more for reliabilty.



why would it still over heat if cooler water is still flowing through the engine?
The reason why the engine over heats when the thermo is stuck closed is cuz the water in the engine is not flowing enough so it just chills there and get hotter

thats why lots of ppl pull the thermo out so there engine will run cooler

The one I looked at :

http://phase2motorsports.stores.yahoo.net/nith.html

I have a twin plate Cusco Exedy Stage 4 clutch. I don't think a crappy Slave is going to cut it with this clutch. I have SS lines also. been using it for 6 months No problems, I do ALOT of drag racing also. So if it was going to break I think it would have. Ill save 234$ and buy another one if it decides to take a poop.

It would over heat b/c the water in the radiator would eventually get as hot as the engine block due too constant flow and cause over heating. I know b/c I use to run Without a thermo in my Rb, It was fine for a while but eventually would heat up, Especially after a few hard pulls.

ESmorz
05-19-2008, 10:16 PM
And you say it has a "clicky gurgling sound". When exactly do you hear this? Are you sure you dont have any leaks? Does it build up good pressure? You shouldnt be able to squeeze the top radiator hose shut when its warmed up. If so, there is air in there, or you have a leak. And the water pump is bad about leaking around the seal too.

I hear it at idle and it seems to go away under throttle.

I'm pretty sure there are no leaks since I don't see any fluid and pressure seems to be good, it just seems coolant isn't flowing properly. I'm gonna go get a new thermo tomorrow when I have some free time. Crossing fingers that's it haha.

deuceforty
05-20-2008, 12:02 AM
dont get an autozone thermo..

just get a nissan OEM thermo, those autozone/advance thermos are pieces of shit, and shit out for no reason....

you can hold a nissan OEM thermo next to a crappy one and the difference is easily visible...

as for the nismo being too cold and hurting your engine, if you look at a cooling diagram the thermo is placed at the end of the circuit, and only opens 10 degrees C earlier than an OEM, by the time that coolant gets back around its not "under temperature"

Mikey213
05-20-2008, 08:36 PM
I.have.a.new.nismo.thermostat.and.it.still.overhea ts.It.has.to.be.air.bubbles.in.the.system
I.ran.around.the.block(giant.parking.lot).a.few.ha rd.times.guage.was.way.past.hot.opened.hood.didn't .seem.to.hot.upper.hose.was.hot.lower.wasn't.No.bo iling.in.overflow.like.a.normal.overheat...so.mayb e.just./air.bubbles?
(Spacebar.is.broken,can't.even.play.starcraft.righ t!)
(lap.top.is.ok.but.gurl.is.always.on.it)
(and.yes.all.my.money.is.going.to.my.sexy.hatchi)

2_fast_240
05-23-2008, 10:39 AM
I hear it at idle and it seems to go away under throttle.

I'm pretty sure there are no leaks since I don't see any fluid and pressure seems to be good, it just seems coolant isn't flowing properly. I'm gonna go get a new thermo tomorrow when I have some free time. Crossing fingers that's it haha.

Ever get your problem worked out? If not, I hate to say it, but you might want to do a compression test. My moms beamer kept having problems overheating. No noticable loss of power or drivability problems. But turned out it was a blown head gasket.

Also, replace your radiator cap since its cheap. I think they sell them with a built in pressure gauge at Advance. Or get a greddy one that bumps up the pressure a bit.

It can be very hard to get all the air out of the system too. That bleeder screw is you best friend here. Loosen it 'til its just barely in there and let the car idle for a while. I even took mine completly out and just let coolant/bubbles pour out some. Make sure your heater is open too.

Mikey213
05-23-2008, 08:16 PM
I didn't try to fix it today (bought a sexy bumper) i am tomarrow. Everything but my water pump is changed. I'm pretty sure there's just air in the system i just like freaking out and posting =0P. I'll jack the front of my car up with my bleeder and rad cap off and add more coolant/water till bubbles are gone and see if that was it.

infinitexsound
05-24-2008, 01:51 AM
why dont u do it the right way when u fill ur radiator.....to bleed it the system from the screw on the mani........ or fill it with the radiator cap off and fill it when the thermostat pops open... and cap it.... i dont feel the need to spend more then 5 bucks for a thermostat... had my autozone one running for 5 years hasnt given me a problem... running no thermostat basically involves more time for your engine to warm up..... i prefer method #2 this basically tell me everything is working properly... might want to change ur waterpump... since you've replaced just about everything else in the cooling system...

if u get temp spikes.. that basically describes having air in ur coolant lines...

ESmorz
05-25-2008, 05:51 PM
I replaced thermo and got an even faster temp spike.

So looks like another flush, to combat the possibility of air in the lines?

Mikey213
05-29-2008, 03:05 PM
IT'S.AIR!Just.bleed.the.air.out.=0)

Sileighty_85
05-29-2008, 06:01 PM
this works pretty well for me when bleeding my system
Once you flush the system

Turn on heater
in second gear go WOT till 6K then engine slow you down
do this 2 or 3 times and that should purge the air out

infinitexsound
05-30-2008, 02:20 AM
thats alot of work..... to bleed air... ill just wait for the thermo to pop open... u can tell when it does, because suddenly the level will drop down and bubble...fill and cap....

ESmorz
06-05-2008, 01:29 AM
Alright I replaced my water pump. Now it will overheat for like 20 seconds and when I rail it, it goes back down to normal and will stay there for the rest of the time...

infinitexsound
06-05-2008, 02:11 AM
replace temp sensor...... then ur golden..... sweet ur so zilvia elite now...

ESmorz
06-06-2008, 05:56 AM
replace temp sensor...... then ur golden..... sweet ur so zilvia elite now...

Already did when I replaced the pump.

Last few times I've run it there have been no temp fluctuations though. hmmm

ESmorz
06-10-2008, 05:32 PM
It started back up again.

If I don't drive it fairly hard for a bit it will start to peak.

ESmorz
06-11-2008, 07:39 PM
Any ideas yet, this making city driving a pain in the ass.

datsun510dude
07-20-2008, 10:09 PM
Im going thru this once again in my car...replaced coolant temp sensor, thermo (twice), water pump, radiator and even installed an aftermarket gauge to keep a more specific eye on the temp.
ANYWAY, after a few hours of reading on this topic, I have noticed a few people trying these spill free funnels that attach to the radiator opening

http://www.twistingwrenches.com/index.php?main_page=product_info&products_id=17407

for $20, I think ill give it a try!

I have also noticed a lot of people installing cheap ass thermostats from napa kregan autozone etc etc.....these thermostats are GARBAGE and tend to prematurely fail and/or stick. for comparison, i got a new oem thermo and replaced a 4 month old cheap autozone thermostat. You can CLEARLY tell the difference, oem one has a rubber seal and appears to be made a lot better with higher quality components.
http://img504.imageshack.us/img504/3151/240thermouc6.jpg

s13tilldeath*
07-28-2008, 06:36 PM
Unhook the thermo it will not overheat in idle anymore but it will still indecate if you over heat. i dont know why it does it but a freind tought me that. there is something about a 240 that is prone to over heat.

Ali 556
07-29-2008, 05:26 PM
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

xpicer
07-29-2008, 11:19 PM
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
07-31-2008, 04:44 PM
did anybody think of a fan clutch???????

ESmorz
08-02-2008, 10:06 PM
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
08-05-2008, 08:19 PM
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
08-06-2008, 09:56 PM
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
08-06-2008, 10:41 PM
Check for hot spots on the radiator. You may have a clogged radiator.

alilvietboi4u
08-06-2008, 10:49 PM
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
08-07-2008, 09:12 AM
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
08-08-2008, 01:07 AM
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
08-08-2008, 01:33 AM
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:
http://memimage.cardomain.com/member_images/12/web/2664000-2664999/2664777_111_full.jpg

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
08-08-2008, 04:14 PM
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
08-12-2008, 06:44 PM
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
08-12-2008, 08:01 PM
did u turn the heater full blast while doing it?:confused:

Dirty Habit
08-12-2008, 08:15 PM
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
08-15-2008, 06:02 AM
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
08-15-2008, 06:17 AM
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
08-15-2008, 09:05 AM
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 (http://www.phatg20.net/component/option,com_remository/Itemid,2/func,select/id,19/)

Here's a downloadable fsm :)