overheating SR

[KoukiMonsta]

i have a redtop in my s14. w/ a koyo rad and e fans. and yesterday it just started randomly overheating. it just gets hotter and hotter up to about 220*then if i pull over it will go down a bit but not less than 200*

i have a temp gauge usually its around ~180 for water.

i have plenty of coolant, weather hasn't been very hot, and it just one day started. e fans ar working too. help me out guys. ive been searching but have checked what ive read and no luck.

[jspaeth]

Check the water/coolant level....is it filled all the way up?

If yes,

The only thing that makes sense is that your water pump somehow has completely failed....

[D.Adams]

your T-STAT ... water pump ... bubble in your system

[jimmytango00]

your T-STAT ... water pump ... bubble in your system

this guy speaks the truth. check all those things he mentioned.

[KoukiMonsta]

yes, the only possible thing could be t stat and water pump from what me and the fellas have decided. and thank you guys for confirming that.

how do i check t stat and water pump? like "bench test" them.

[jspaeth]

yes, the only possible thing could be t stat and water pump from what me and the fellas have decided. and thank you guys for confirming that.

how do i check t stat and water pump? like "bench test" them.

If the thermostat is stuck closed, the radiator will feel cool even when your water temps are hi.

THe first time I put on my new OEM thermostat, it didn't open right away when it was supposed to...

My water temps were like 90-92C, but the radiator was perfectly cool. Then finally it opened, and I haven't had an issue since.

But if yours has failed closed, the radiator/return hoses should be very cool.


This is also true for the water pump being faulty....however, "natural" convection or even a "weak" water pump will still allow SOME circulation of the water, so it may not be as obvious to tell by just feeling the hoses.....

[fliprayzin240sx]

No real way of checking water pumps. If they are spinning, the pulley will be spinning. As long as its doing that and the pump isnt leaking/weeping, it should be good.

T-stat...take it out and stick it in hot water on a pot. Take a thermometer and see what temp it fully opens up at.

[SleepR 240sx]

Water pump should have a weep hole. If it's bad you can sometimes see a little dripping of water from underneath it.

[KoukiMonsta]

well i tried to bleed it out today, no bubbles at all.

and after full warmup the rad was hot. too.....

while i warmed up (w/ front jacked up) the water level continued to rise and spill out as it warmed up, is that normal?

[Portuguese Bend]

Is that with the radiator cap on or off?

[KoukiMonsta]

Is that with the radiator cap on or off?

ooofffffffffffffffffff, then once fully warm on to test line pressure.

[Portuguese Bend]

If you've done / checked everything else. You might want to check for a leaky head gasket.

Check to make sure the coolant system holds pressure. Check cylinder compression. If it's not equal across the board and up to spec, diagnosis with a proper leak down test.

Sounds like the coolant system is getting overwhelmed. Whether because you don't have enough cooling capacity or something is heating up the coolant system beyond it's capacity to cool the engine. There are a thousand questions that could be asked to troubleshoot. More than it seems you have the patience for on a message board. Troubleshooting overheating issues is an extensive process. Good luck.

[Chrischeezer]

does it over heat when its sitting idle? or only when your driving?

what have u touched last before this started to happen?

[KoukiMonsta]

does it over heat when its sitting idle? or only when your driving?

what have u touched last before this started to happen?

while driving, it will actual lower a bit at idle. i didnt do anything to affect it. havent changed anything in quite a while.

[Chrischeezer]

Didn't mess with your fan wiring? or anything like that? (fans pulling not pushing right?)
If your thermostat was stuck closed it would most likely overheat at idle too...
If you headgasket was blown you would have a ton of air/compression in your radiator...

just for piece of mind, you can unbolt your water pump, but ive never seen an sr20 water pump fail... should be good for 80k miles.

[KoukiMonsta]

Didn't mess with your fan wiring? or anything like that? (fans pulling not pushing right?)
yes they are pulling as usual

If your thermostat was stuck closed it would most likely overheat at idle too...
intersting, good point. now when i say lowers i mean from 215* to 200* in ~5 minutes. but still hight than my usual 180* i have been seeing ever ri installed my water temp gauge months ago

If you headgasket was blown you would have a ton of air/compression in your radiator...
thats what i figured, i could see some bubbles in the rad

just for piece of mind, you can unbolt your water pump, but ive never seen an sr20 water pump fail... should be good for 80k miles.

ya, i mean the pully spins the pump, which is not all that complicated, doesnt seem to leak....

but when you say remove it for peace of mind, what am i looking for?


meeessagggeee length

[D.Adams]

How many miles on the motor. Just because the water pump has a weep hole and nothing is coming out of it doesn’t mean it’s bad. I have replaced water pumps where all the pump blades were gone.

this is that i would do

replace T-Stat ( if it still over heats ) v
replace Water Pump ( if it still over heats ) v
replace radiator cap ( if it still over heats ) v
do a full flush on the system ( if it still over heats ) v
do a leak down test ( if it still over heats ) v
replace the head gasket ( if it still over heats ) v


set the car on fire

[KoukiMonsta]

How many miles on the motor. Just because the water pump has a weep hole and nothing is coming out of it doesn’t mean it’s bad. I have replaced water pumps where all the pump blades were gone.

this is that i would do

replace T-Stat ( if it still over heats ) v
replace Water Pump ( if it still over heats ) v
replace radiator cap ( if it still over heats ) v
do a full flush on the system ( if it still over heats ) v
do a leak down test ( if it still over heats ) v
replace the head gasket ( if it still over heats ) v


set the car on fire

im about to burn this fucker!!

heres my water pump i just pulled it out...looks ok.....
http://i106.photobucket.com/albums/m249/kitefl/IMG_4263.jpg


pulled the tstat too, need to get a thermometer to test it in some hot water.

i am going to put in some distilled h2o and water wetter too. since i lost so much fluid doing that, can anybody direct me to the sr coolant flush procedure? i cant read japanese.

[D.Adams]

this is the kit i use on most my coolant flushes.. its really easy to use and it comes with its own distruction's. i just did mine like 2 months ago didnt even think of doing a write up on it.

AutoZone.com | FlushandFillRadiatorKit | ProfessionalFlushandFillRadiatorCleanerKit (http://www.autozone.com/autozone/catalog/accessories/accProductDetails.jsp?displayName=FlushandFillRadi atorKit&itemId=36-10&navValue=100036&parentId=null&productId=525931&fromString=&itemIdentifier=525931_0_0_&filterByKeyWord=&categoryNValue=&store=5303&skuDisplayName=ProfessionalFlushandFillRadiatorCle anerKit&categoryDisplayName=&_requestid=1167818)

http://www.autozone.com/autozone/flushFill/flushFill.jsp?intcmp=

[Sileighty_85]

Water pump is fine

Replace the Thermo with a Nismo
and replace the Radiator Cap.

Go ahead an flush the crap out of it

and make sure that the radiator is free of obtructions

check to make sure the E-fans arent glitching (check/shake the harness)

[kushlivin]

replace the water pump run no thermostat, that is most likely what is wrong

[KoukiMonsta]

Water pump is fine

Replace the Thermo with a Nismo
and replace the Radiator Cap.

Go ahead an flush the crap out of it

and make sure that the radiator is free of obtructions

check to make sure the E-fans arent glitching (check/shake the harness)

does the stock thermo open at 76.5* c?
rad cap is nismo and failry new.

check rad is free of obstructions? i will flush soon......
efans are always working when i check...no issues there.

i am going to run it with no thermo tmmrw and see if it works, tho it opened up in some hot water

[Sileighty_85]

does the stock thermo open at 76.5* c?
rad cap is nismo and failry new.

check rad is free of obstructions? i will flush soon......
efans are always working when i check...no issues there.

i am going to run it with no thermo tmmrw and see if it works, tho it opened up in some hot water

Yeah opens at 76.5 A nismo One will open at 63ish*c (cant remember exactly)
My setup runs no hotter than 70*C on a hot day (Koyo and E-fans also with Nismo Cap and thermo )

Yeah check the rad for obstructions, like trash bags, leaves, mud any crap that will block air flow through the Radiator. Check the A/C condenser also.

Well if the wiring is iffy when you hit bumps and make sharp turn it might make the e-fans glitch.

Make sure you bleed it good.