Sr20det: Cavitation or lifting head? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

kikcaffine · 07-21-2010, 01:20 PM

Im having an odd problem with my SR, and I was wondering if you guys could lead me in a direction to start figuring whats wrong with it. Its a black top s13 sr, with 550's and a 2860RS turbo. Its currently set to 17psi on stock internals and tuned for it. When ever though the car is over 6000rpm the temp gauge will jump up for a split second then settle right back down. It's like it jumps about half a temp mark then comes right back to where it was before, between the second and third temp. mark. Is this cavitation or is it lifting the head when its doing this?

R@ddy · 07-21-2010, 01:26 PM

do you still have the stock head bolts?

kikcaffine · 07-21-2010, 01:38 PM

Quote:

Originally Posted by e1_griego

Bad grounds?

You have any other way to monitor water temp besides stock dummy gauge?

Stock dummy gauge

Quote:

Originally Posted by s13_kidd

do you still have the stock head bolts?

Yes, stock internally

jspaeth · 07-21-2010, 01:27 PM

Quote:

Originally Posted by kikcaffine

Im having an odd problem with my SR, and I was wondering if you guys could lead me in a direction to start figuring whats wrong with it. Its a black top s13 sr, with 550's and a 2860RS turbo. Its currently set to 17psi on stock internals and tuned for it. When ever though the car is over 6000rpm the temp gauge will jump up for a split second then settle right back down. It's like it jumps about half a temp mark then comes right back to where it was before, between the second and third temp. mark. Is this cavitation or is it lifting the head when its doing this?

Couldn't that just be that the water is getting hotter in the vicinity of the sensor before it gets a chance to pass to the thermostat and cause the flow to increase?

e1_griego · 07-21-2010, 01:30 PM

Bad grounds?

You have any other way to monitor water temp besides stock dummy gauge?

slider2828 · 07-21-2010, 04:13 PM

Cavitation only occurs over a period of time when the water circulates at a high rate over a period of time.... Signs of cavitation usually is water spitting out of the reservoir, then lack of water cause heat temp rising, but it doesn't make meters jump....

For me its constant 6-7k rpm drives on the track abouve 5 sessions into it at the end of the day.... never happens on the stret.

Def · 07-21-2010, 04:46 PM

Stock dummy gauge is worthless. I was hitting 230 deg F coolant in the upper hose after coming off track(it was 104 in the shade one day - it was cooler on track, but no matter how long of a cooldown it'd heat up once parked). The stock gauge never moved that I could tell.

Get a real gauge on there and check it out.

Are you losing coolant or popping the rad cap?

WISH ONE · 07-21-2010, 04:53 PM

def is right, usually on the stock gauge by the time it shows you temp rising your pretty much already overheated.

voltage problem or ground.

kikcaffine · 07-21-2010, 08:13 PM

Quote:

Originally Posted by Def

Stock dummy gauge is worthless. I was hitting 230 deg F coolant in the upper hose after coming off track(it was 104 in the shade one day - it was cooler on track, but no matter how long of a cooldown it'd heat up once parked). The stock gauge never moved that I could tell.

Get a real gauge on there and check it out.

Are you losing coolant or popping the rad cap?

Not losing any coolant or doing anything out of the ordinary. It started though i think after I resealed the upper water neck that comes off the head.

Quote:

Originally Posted by WISH ONE

def is right, usually on the stock gauge by the time it shows you temp rising your pretty much already overheated.

voltage problem or ground.

I see.

kikcaffine · 07-22-2010, 09:43 PM

I shot these two videos earlier tonight, they were done in second gear, since that seems to be the only time it happens. I did notice the bellhousing was all wet on the passenger side and the top of the motor on that side had an unusal amount of shit build up compared to the rest of the engine.

YouTube - Sr20det

slider2828 · 07-23-2010, 10:59 AM

Maybe you have a coolant leak under your intake manifold.... either way wetness = coolant leak done....

kikcaffine · 07-23-2010, 12:08 PM

Quote:

Originally Posted by slider2828

Maybe you have a coolant leak under your intake manifold.... either way wetness = coolant leak done....

Ok, would that also be the cause of the temp gauge fluctuating also? I'd just like to have a plan of attack when I go and start looking for leaks.

07-21-2010, 01:20 PM	#1
kikcaffine Zilvia Addict Join Date: Aug 2009 Location: Marietta, Ga Posts: 713 Trader Rating: (2) Feedback Score: 2 reviews	Sr20det: Cavitation or lifting head? Im having an odd problem with my SR, and I was wondering if you guys could lead me in a direction to start figuring whats wrong with it. Its a black top s13 sr, with 550's and a 2860RS turbo. Its currently set to 17psi on stock internals and tuned for it. When ever though the car is over 6000rpm the temp gauge will jump up for a split second then settle right back down. It's like it jumps about half a temp mark then comes right back to where it was before, between the second and third temp. mark. Is this cavitation or is it lifting the head when its doing this?

07-21-2010, 04:13 PM	#6
slider2828 Post Whore! Join Date: Oct 2004 Location: San Francisco, CA Posts: 6,040 Trader Rating: (13) Feedback Score: 13 reviews	Cavitation only occurs over a period of time when the water circulates at a high rate over a period of time.... Signs of cavitation usually is water spitting out of the reservoir, then lack of water cause heat temp rising, but it doesn't make meters jump.... For me its constant 6-7k rpm drives on the track abouve 5 sessions into it at the end of the day.... never happens on the stret. __________________ Turn and Burn!

07-21-2010, 04:46 PM	#7
Def Post Whore! Join Date: Apr 2004 Location: Houston, TX Posts: 2,701 Trader Rating: (16) Feedback Score: 16 reviews	Stock dummy gauge is worthless. I was hitting 230 deg F coolant in the upper hose after coming off track(it was 104 in the shade one day - it was cooler on track, but no matter how long of a cooldown it'd heat up once parked). The stock gauge never moved that I could tell. Get a real gauge on there and check it out. Are you losing coolant or popping the rad cap? __________________ S13 Hatch - Goes around tracks quickly DEFSPORT

07-21-2010, 04:53 PM	#8
WISH ONE Post Whore! Join Date: Aug 2006 Location: orange county ca Posts: 2,738 Trader Rating: (13) Feedback Score: 13 reviews	def is right, usually on the stock gauge by the time it shows you temp rising your pretty much already overheated. voltage problem or ground. __________________ PARTING/SELLING MY COUPE. PM ME.

07-23-2010, 10:59 AM	#11
slider2828 Post Whore! Join Date: Oct 2004 Location: San Francisco, CA Posts: 6,040 Trader Rating: (13) Feedback Score: 13 reviews	Maybe you have a coolant leak under your intake manifold.... either way wetness = coolant leak done.... __________________ Turn and Burn!

07-21-2010, 01:26 PM	#2
R@ddy Nissanaholic! Join Date: Jul 2008 Location: SoCal Age: 35 Posts: 1,632 Trader Rating: (32) Feedback Score: 32 reviews	do you still have the stock head bolts?

07-21-2010, 01:30 PM	#5
e1_griego Post Whore! Join Date: Sep 2004 Location: Independence, Ore. Age: 40 Posts: 2,722 Trader Rating: (24) Feedback Score: 24 reviews	Bad grounds? You have any other way to monitor water temp besides stock dummy gauge?

07-22-2010, 09:43 PM	#10
kikcaffine Zilvia Addict Join Date: Aug 2009 Location: Marietta, Ga Posts: 713 Trader Rating: (2) Feedback Score: 2 reviews	I shot these two videos earlier tonight, they were done in second gear, since that seems to be the only time it happens. I did notice the bellhousing was all wet on the passenger side and the top of the motor on that side had an unusal amount of shit build up compared to the rest of the engine. YouTube - Sr20det