Overheating at high rpms or high speed only - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Eramo323 · 10-09-2012, 02:16 PM

Raidiator bubbles :/ - YouTube

Only overheating at high RPMS and or High Speed
Thermostat was removed because i thought it was possibly stuck closed
fan clutch is working properly (or so I think?)
no signs of leaks -.-
I provided a video that i uploaded to YouTube showing tiny air bubbles every time i give the engine gas...
I'm thinking possible head gasket?
Not sure tho, There is no coolant in the oil or oil in the coolant and no white smoke coming from the tail pipe

s13mikesr20 · 10-09-2012, 02:21 PM

Outer headgasket is muffed up recommend radiator pressure text and leak down test

shagspeed · 10-09-2012, 03:30 PM

Quote:

Originally Posted by s13mikesr20

Outer headgasket is muffed up recommend radiator pressure text and leak down test

DO NOT remove the thermostat .... The dam SR20 pumps flow crazy volume... The Thermostat acts as a restriction .. You take it out and for sure it will over heat .... The water passes the core quick enough it can't cool.. A larger radiator will help put at least cut out the spring and maybe the diaphragm if its truly stuck but water volume needs to be slowed down ...

Also bubbles could be that the water is boiling in the block or head .. This too is very bad if air gets stuck in the block as it will create hot spots and I have seen engines lost to this as well ...

I recommend running Evans NRG+ if you can afford it.. It will not boil tell 375* and it doesn't expand .. You can also run a ZERO or LOW pressure cap and it will be easier on all your coolant lines as well ..

1. Replace TSTAT
2. Evans NRG+ Coolants » Engine Cooling Systems
3. Optional - Low or Zero pressure cap ..

Hope that helps ..

dawagarage · 10-09-2012, 07:47 PM

higher rpms/speeds = more rpms = more explosions = more heat.
step up your cooling system. (your probably knew this.. maybe the next person doesnt?)

also, something else i recently learned about, (in regards to you removing the thermostat that acts as a restrictor) is cavitation damage to front cover, water pump, etc.)

Prozac · 10-09-2012, 08:09 PM

Get a thermostat , cooling requires time!

Bubbles , you either have air in your cooling system or headgasket problem , feeding back crankcase pressure into cooling system. Start the car cold with the rad cap off get up to operatiing temp, holding throttle around 3k rpm , once your thermostat opens you should get a flow , throttle the engine and watch for bubbles , burp the cooling system of air you should have a bleeder screw on the neck 10m open it wait for fluid and tighten. Let cool down remove rad cap ,start car hold throttle at around 2.5 rpm and if you get bubbles you have Mild HG problem that could blow a rad , hoses and more.

RU4REAL · 10-09-2012, 10:17 PM

It wouldn't hurt to check your timing. SR's like 15 degrees. Anything less, you'll get heat soaked and temps will rise.

Natural Aspirations · 12-15-2012, 04:54 PM

Looks like you need a head gasket. Have you figured it out if not I can help.

JFoxx · 12-15-2012, 05:14 PM

something else that could effect it are pinholes in your cooling system, they will draw air into your cooling system (wont leak) and sr absolutely hate air in the system, it happend to me before....

steve shadows · 12-15-2012, 05:26 PM

Quote:

Originally Posted by Eramo323

Raidiator bubbles :/ - YouTube

Only overheating at high RPMS and or High Speed
Thermostat was removed because i thought it was possibly stuck closed
fan clutch is working properly (or so I think?)
no signs of leaks -.-
I provided a video that i uploaded to YouTube showing tiny air bubbles every time i give the engine gas...
I'm thinking possible head gasket?
Not sure tho, There is no coolant in the oil or oil in the coolant and no white smoke coming from the tail pipe

You should always run a thermostat...it helps keep the pressure in the cooling system at the correct level. Get a nismo one asap. Also I would do a leak down and compression test when the motor is cold to see if anything on the head is leaking. Good luck!

Wookie384 · 12-15-2012, 05:50 PM

It might be a long shot but with the thermostat out, the cooling system is flowing too freely, and every-time your at high engine speeds the water pump could be cavitating causing air to separate from the coolant and appear in the system.

240shawty · 12-15-2012, 06:07 PM

im pretty sure that running the engine with the radiator cap off bleeds the coolant system of air.....

rb25_s13*CHUKI · 12-15-2012, 06:13 PM

Quote:

Originally Posted by 240shawty

im pretty sure that running the engine with the radiator cap off bleeds the coolant system of air.....

Hold up pause that motion, that is false son!

240shawty · 12-15-2012, 06:10 PM

like the wookie mobile

Wookie384 · 12-15-2012, 08:05 PM

Quote:

Originally Posted by 240shawty

like the wookie mobile

uhhhh....what are you trying to say? lol

Kingtal0n · 12-15-2012, 10:27 PM

you can also get bubbles if the coolant is contaminated with power steering fluid or any number of other car related fluids.

Pressure the coolant system with the engine off and check for leaks. A leak can let water out, or air in. Do NOT flip out and automatically assume the headgasket is toast.

And, I see metal end tanks. Is that a KA radiator?

JFoxx · 12-15-2012, 06:18 PM

^^^ what he said..... but a swirl pot will....

240shawty · 12-15-2012, 06:42 PM

well please inform me then

*wangan_cruiser* · 12-15-2012, 06:56 PM

Bubbles 100%

Eramo323 · 12-30-2012, 05:33 PM

water pump gasket was fucked!

jt1583 · 12-30-2012, 09:23 PM

I believe you but how would air get into the coolant system from a bad WP gasket? Just curious, glad you found the issue.

*fliprayzin240sx* · 01-03-2013, 10:31 PM

Quote:

Originally Posted by jt1583

I believe you but how would air get into the coolant system from a bad WP gasket? Just curious, glad you found the issue.

Serious question? What happens when you pour water out of a cup? Does the water level stay the same?

Eramo323 · 01-03-2013, 01:36 PM

^^^ no clue but I replaced it and the thermostat housing gasket and it stopped heating up and losing coolant

shaggy sr · 01-03-2013, 01:37 PM

the same happened to me. check my thread. Maybe it will help u

10-09-2012, 02:16 PM	#1
Eramo323 Zilvia Addict Join Date: Jun 2010 Location: NORTH EAST LOS ANGELES Age: 36 Posts: 764 Trader Rating: (22) Feedback Score: 22 reviews	Overheating at high rpms or high speed only Raidiator bubbles :/ - YouTube Only overheating at high RPMS and or High Speed Thermostat was removed because i thought it was possibly stuck closed fan clutch is working properly (or so I think?) no signs of leaks -.- I provided a video that i uploaded to YouTube showing tiny air bubbles every time i give the engine gas... I'm thinking possible head gasket? Not sure tho, There is no coolant in the oil or oil in the coolant and no white smoke coming from the tail pipe

10-09-2012, 07:47 PM	#4
dawagarage Nissanaholic! Join Date: Sep 2006 Location: Bremerton, WA Age: 40 Posts: 2,037 Trader Rating: (23) Feedback Score: 23 reviews	higher rpms/speeds = more rpms = more explosions = more heat. step up your cooling system. (your probably knew this.. maybe the next person doesnt?) also, something else i recently learned about, (in regards to you removing the thermostat that acts as a restrictor) is cavitation damage to front cover, water pump, etc.) __________________ formerly known as "hotboiblaze" ratsun: dawa (73 datsun 620) clublexus: properD (97 sc300)

12-15-2012, 04:54 PM	#7
Natural Aspirations Join Date: Dec 2012 Location: Torrance CA Posts: 16 Trader Rating: (0) Feedback Score: 0 reviews	Did you thigure it out? Looks like you need a head gasket. Have you figured it out if not I can help.

12-15-2012, 10:27 PM	#15
Kingtal0n Post Whore! Join Date: Jul 2005 Location: South Florida Age: 42 Posts: 4,829 Trader Rating: (17) Feedback Score: 17 reviews	you can also get bubbles if the coolant is contaminated with power steering fluid or any number of other car related fluids. Pressure the coolant system with the engine off and check for leaks. A leak can let water out, or air in. Do NOT flip out and automatically assume the headgasket is toast. And, I see metal end tanks. Is that a KA radiator? __________________ 5.3/4l80e/turbo 240sx playthrough: tinyurl.com/4l80er

12-15-2012, 06:42 PM	#17
240shawty Join Date: Jul 2011 Location: newnan ga Age: 35 Posts: 36 Trader Rating: (0) Feedback Score: 0 reviews	well please inform me then Last edited by 240shawty; 12-15-2012 at 07:43 PM..

10-09-2012, 02:21 PM	#2
s13mikesr20 Nissanaholic! Join Date: Sep 2011 Location: las vegas Age: 35 Posts: 1,792 Trader Rating: (8) Feedback Score: 8 reviews	Outer headgasket is muffed up recommend radiator pressure text and leak down test

10-09-2012, 08:09 PM	#5
Prozac Leaky Injector Join Date: Aug 2011 Location: Ky Age: 44 Posts: 89 Trader Rating: (3) Feedback Score: 3 reviews	Get a thermostat , cooling requires time! Bubbles , you either have air in your cooling system or headgasket problem , feeding back crankcase pressure into cooling system. Start the car cold with the rad cap off get up to operatiing temp, holding throttle around 3k rpm , once your thermostat opens you should get a flow , throttle the engine and watch for bubbles , burp the cooling system of air you should have a bleeder screw on the neck 10m open it wait for fluid and tighten. Let cool down remove rad cap ,start car hold throttle at around 2.5 rpm and if you get bubbles you have Mild HG problem that could blow a rad , hoses and more.

10-09-2012, 10:17 PM	#6
RU4REAL Leaky Injector Join Date: Dec 2010 Location: SoCal Age: 54 Posts: 96 Trader Rating: (0) Feedback Score: 0 reviews	It wouldn't hurt to check your timing. SR's like 15 degrees. Anything less, you'll get heat soaked and temps will rise.

12-15-2012, 05:14 PM	#8
JFoxx BANNED Join Date: May 2008 Location: SD & OC Posts: 722 Trader Rating: (3) Feedback Score: 3 reviews	something else that could effect it are pinholes in your cooling system, they will draw air into your cooling system (wont leak) and sr absolutely hate air in the system, it happend to me before....

12-15-2012, 05:50 PM	#10
Wookie384 Zilvia Addict Join Date: May 2007 Location: N. Hollywood / Burbank Age: 40 Posts: 766 Trader Rating: (10) Rides Gallery: Wookie384 Feedback Score: 10 reviews	It might be a long shot but with the thermostat out, the cooling system is flowing too freely, and every-time your at high engine speeds the water pump could be cavitating causing air to separate from the coolant and appear in the system.

12-15-2012, 06:07 PM	#11
240shawty Join Date: Jul 2011 Location: newnan ga Age: 35 Posts: 36 Trader Rating: (0) Feedback Score: 0 reviews	im pretty sure that running the engine with the radiator cap off bleeds the coolant system of air.....

12-15-2012, 06:10 PM	#13
240shawty Join Date: Jul 2011 Location: newnan ga Age: 35 Posts: 36 Trader Rating: (0) Feedback Score: 0 reviews	like the wookie mobile

12-15-2012, 06:18 PM	#16
JFoxx BANNED Join Date: May 2008 Location: SD & OC Posts: 722 Trader Rating: (3) Feedback Score: 3 reviews	^^^ what he said..... but a swirl pot will....

12-15-2012, 06:56 PM	#18
wangan_cruiser kouki man Join Date: Apr 2006 Location: downtown oakland,ca Age: 40 Posts: 3,539 Trader Rating: (36) Feedback Score: 36 reviews	Bubbles 100%

12-30-2012, 05:33 PM	#19
Eramo323 Zilvia Addict Join Date: Jun 2010 Location: NORTH EAST LOS ANGELES Age: 36 Posts: 764 Trader Rating: (22) Feedback Score: 22 reviews	water pump gasket was fucked!

12-30-2012, 09:23 PM	#20
jt1583 Zilvia Member Join Date: Jul 2005 Location: Georgia Age: 37 Posts: 264 Trader Rating: (3) Feedback Score: 3 reviews	I believe you but how would air get into the coolant system from a bad WP gasket? Just curious, glad you found the issue.

01-03-2013, 01:36 PM	#22
Eramo323 Zilvia Addict Join Date: Jun 2010 Location: NORTH EAST LOS ANGELES Age: 36 Posts: 764 Trader Rating: (22) Feedback Score: 22 reviews	^^^ no clue but I replaced it and the thermostat housing gasket and it stopped heating up and losing coolant

01-03-2013, 01:37 PM	#23
shaggy sr Zilvia FREAK! Join Date: Jun 2011 Location: queens, nyc Posts: 1,454 Trader Rating: (7) Feedback Score: 7 reviews	the same happened to me. check my thread. Maybe it will help u __________________ Last edited by shaggy sr; 01-03-2013 at 03:26 PM..