Overheating.... w/ no Thermostat

[ZOMG.SR20]

how is this possible i completely bled the system took out the thermostat (cause the old was autozone special that got stuck shut) it over heats underrevving but not idling

i used prestone 50/50

[SR24DET]

Cause there are many other things that attribe to your coolant system.

1. Check for leaks. They lower your booling point.2. Make sure there is no air bubbles in your system.3. Thermistat (which you did)4. Water pump5. And if all that doesnt work Im not sure what to tell you. Some say radiator, but is only bad if it leaks or is plugged.

[ksdmed]

Ther is nothing to restrict the flow of water the cool.

[24j0hn]

why do people take out the thermostat, its there for a reason... the thermostat opens and closes with heat so when it closes the cylinders/sleeves heat up the coolant and once the coolant gets hot enough the thermostat opens and puts the hot coolant into the radiator and gets cooled while the coolant that was in the radiator is now around the cylinders... and this goes on and on and on

without the thermostat the temperature cant be controlled and will either be cold(which wastes gas and parts are promised to wear rapidly) or hot( which will make parts fail)...

just go to nissan and order a 240sx oem nissan thermostat which will not fail or be faulty and if it does it has a warranty... its like $25 or get nismo

[2056515]

im pretty sure he knows what a thermostat does, but he has overheating issues without it...so he knows something else is wrong. And have you ever bled the air out of a KA cooling system??....

Ther is nothing to restrict the flow of water the cool.

huh???

i would think its your waterpump not working properly and not circulating your cooling system

[hungryjoseph]

if you can get your hands on an air compressor: take out all your spark plugs and radiator cap. attach hose to spark plug hole of a cylinder while that piston is at tdc, and look for bubble coming through your fluid in your radiator. repeat for all 4 cylinders and if you see air, you have a bad headgasket. if you can't do this then just get a compression tester from advanced for 15$ and check your compression. it wont tell you everything but it gets you started somehwere

[ZOMG.SR20]

btw i have a SR and a apexi HG

Cause there are many other things that attribe to your coolant system.

1. Check for leaks. They lower your booling point.2. Make sure there is no air bubbles in your system.3. Thermistat (which you did)4. Water pump5. And if all that doesnt work Im not sure what to tell you. Some say radiator, but is only bad if it leaks or is plugged.

I know what the problem is then my heater core line through the intake is not completely tightened down yet

so leaks

why do people take out the thermostat, its there for a reason... the thermostat opens and closes with heat so when it closes the cylinders/sleeves heat up the coolant and once the coolant gets hot enough the thermostat opens and puts the hot coolant into the radiator and gets cooled while the coolant that was in the radiator is now around the cylinders... and this goes on and on and on

without the thermostat the temperature cant be controlled and will either be cold(which wastes gas and parts are promised to wear rapidly) or hot( which will make parts fail)...

just go to nissan and order a 240sx oem nissan thermostat which will not fail or be faulty and if it does it has a warranty... its like $25 or get nismo

umm its summer ill put one in when colder weather rolls arond but I dont have any HVAC components anyway so...

[tEknoS13]

Completely agree with hungryjoseph

[24j0hn]

Completely agree with hungryjoseph

you could try a pressure test but make sure you dont over pressurize cuz you could blow the head

[ZOMG.SR20]

HG IS FINE omg its not leaking i checked that when i first bought the motor

[boro drift]

Without the thermostat, the coolant flows too quickly through the system. If the coolant doesn't spend enough time in the radiator, the radiator cannot do it's job, putting hot coolant back into the engine.

[themadscientist]

Put the thermostat back in. That isn't the problem. Your logic that removing the thermostat aids summer cooling is completely misguided and flat out wrong. The thermostat holds the water in the engine until it reaches the optimum temperature, then lets it go. Two things result:

1. The water is able to absorb more engine heat before heading to the radiator thus cooling better. The idea is to pull the heat out of the metal; water screaming through the passages unmetered is wildly inefficient at that task. Smack your turbo, now, grab it. Which burns more. Repeat as needed to grasp the concept.

2. Engine temperatures do not fluctuate allowing the computer to meter fuel more precisely and efficiently thus aiding in power and fuel economy. The injector pulsewidth is optimized to several metrics, one being engine temp. If it swings up and down wildly like it will without a thermostat the computer has a harder time of getting the mix right.

Yanking the thermostat is an old wives tale and does no good, only harm.

Water pump actually working?

Radiator plugged up?

Check those.

[ZOMG.SR20]

I order new thermostat from nissan then

[themadscientist]

If you are unsure about the radiator have it professionally flushed. Are you using the KA one? You need a two core at least.

[hotrod240sx]

put the thermostat back in, with it out the water is spending enough time in the radiator to cool, the water is moving through to fast and will not cool properly. it is indeed an ole wise tell and if it was to work like said without a thermostat it is because the vehicle had 1 hell of a cooling system to start with. i would install a good thermostat and bleed the system. it is a pain at times to bleed.

[hungryjoseph]

I know what the problem is then my heater core line through the intake is not completely tightened down yet

so leaks

i don't get it you know where it's leaking and you came to ask for help? if you have a metal hg, it can still leak and blow, it is just more difficult to do it. i've seen it happen twice to apexi hg's and once to a cometic. so i wouldn't rule it out but its definately not the first thing i'd check

[ZOMG.SR20]

yes im using the KA one but aren't 180sx's equipped with the same Radiators?

i don't get it you know where it's leaking and you came to ask for help? if you have a metal hg, it can still leak and blow, it is just more difficult to do it. i've seen it happen twice to apexi hg's and once to a cometic. so i wouldn't rule it out but its definately not the first thing i'd check

i want to see what else could cause the problems
Modified by ZOMG.SR20 at 9:56 PM 8/16/2009

[themadscientist]

No. If the KA24 is equipped like the CA18DE and SR20DE, you have a one core radiator, about 1/2" thick. The SR20DET have a double-stacked core. Absolute minimum I would trust.If you are unsure what you have take the cap off and look in. if you only see one row of holes, it's a one core, two rows of holes, a two core. If you do have a two core, that should work. To check for a clogged core. touch the fins lightly at various spots. If there are areas that are noticably colder than the rest of the core you may have junk clogging up the tubes. Have the radiator professionally flushed.BE AWARE, often when you have this done, leaks will show up and need to be repaired. The pinhols were stopped up with junk and when flushed the radiator fails at these points so have it pressure-checked. Any professional radiator shop should do this without asking but ask anyway.

[hungryjoseph]

are you loosing a considerable amount of coolant without seeing it go through the exhaust? have you run through all the coolant hoses? under intake manifold, heater hoses, if u have an s13 sr the coolant hose right behind the head on the firewall, water pump area. after doing this i would do a leak down / compression test, but if you're dead set on that being good then i'd listen to themadscientist and get your hands on a dual core rad mainly because that costs more to do than testing for a bad hg

[ZOMG.SR20]

it has to do with the combination of no thermostat, nonworking elctric fan, and a leaky heater core hose... ithink

im not losing any its just i was wondering why it wasnt cooling.... sorry if i failed to mention that

[hungryjoseph]

so you have no fan and you know you're leaking coolant and you're askign us why your car is voer heating

[OutToWinPAHC]

ZOMG, email me at [email protected], I got an offer for you.

[SR24DET]

put the thermostat back in, with it out the water is spending enough time in the radiator to cool, the water is moving through to fast and will not cool properly.

Really? Then why is it that on the race cars I have made, I removed it and they all ran 25% cooler? On the 240sx my heat gague is normally at half way. After removeing it its at 1/4 way? Even when I go to a drift even and beat the living piss out of it, it doesnt go up? And I have a stock rad too.

Im not saying you did this but alot of people say that, but they have never tried it. The thermistate just makes the engine heat up faster. It makes hot coolant build up faster so it can flow to the heater core and give you heat ASAP.

[OutToWinPAHC]

Umm the CTS also plays a part in this, Emissions will be horrid without a tstat, but proper warm up of an engine is crucial for normal operations, drag car sis another story, because of the limited times being used and the cool down while waiting with the engine off.

But sounds like an air issue, really does. Call a few local shops see if the have a vacuum purge system. It allows you to test the cooling system drained under vacuum, if it holds there are no leaks, then wile under vacuum you can fill the system with no air entering all all, no need to bleed.

[SR24DET]

Umm the CTS also plays a part in this, Emissions will be horrid without a tstat, but proper warm up of an engine is crucial for normal operations, drag car sis another story, because of the limited times being used and the cool down while waiting with the engine off.

I was refering to drifting. I will go to a drift day and slide around for 8 hrs and have no over heating problems. Pressure checking the system does sound like a good idea.

[hotrod240sx]

And I know for a fact that some cars it will make them run hotter I never said that it would in all but it is jerks like you that just want to criticize everything rather than try to help someone and if you wanna copy and post on something someone says copy the whole thing

[SR24DET]

I wasnt being a jerk. I almost never flame or b**** at people on here. Im just not that way. I am posting on here to help. I also copy only part of what someone said because its what I am refering too. I do agree that it doesnt always work. I believe that my buddy told me that it is worse on LSX engines. Im just saying it does help sometimes, and a KA is a time that it helps. If you feel like im being a d!ck im sorry.

[hotrod240sx]

well what made me mad was you flame and I wasn't the only 1to make the same statement

[2056515]

well what made me mad was you flame and I wasn't the only 1to make the same statement

on which post was he flaming??!!?...he was only stating that if everything works properly on your car and you dont run a thermostat....its impossible to overheat....and he is correct.

[Coeur de lion]

The answer is simple. It's summer time and you have not fed your motor ice cream!

Try that first!