SR heats up at idle, cools while driving - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

kyral · 03-16-2016, 11:03 PM

I have an SR that heats up at idle and keeps climbing but when i i get moving it starts cooling down. i dont think its a warped head or headgasket issue because itcools itself back down and the coolant doesnt geyser out of the rad cap when i open it

has an aluminum rad and a FMIC

I read it might be a clogged cooling system, air in the system, a half stuck thermostat or my cooling fans.

im gonna get a coolant flush. i tried to bleed the air today but i might not have done it right (removed the bleeder screw by the exhaust side of engine)

anyone got any input on this?

jr_ss · 03-16-2016, 11:29 PM

Are your fans working? They all heat up at idle, but usually a radiator fan/s turn on you cool them off.

hanzbrady · 03-17-2016, 06:20 AM

You have air in your system, I'd assume that if you revved your car at idle it'd probably cool down as well. My car had the same issue and it turned out to be a cracked coolant line under my intake

zenkicpe · 03-17-2016, 06:32 AM

Tip on burping air out of your system..
Pull your car up on ramps or put blocks under the front tires or park on a decent incline so that the radiator is the highest point. Find a funnel that will fit snugly into the radiator neck. Fill funnel about half way up with coolant. Start car and let idle, the air will burp up and out of the funnel as it works it way around to the radiator. Massage the radiator hoses at it warms and blips the throttle every now and then.

hanzbrady · 03-17-2016, 06:56 AM

Quote:

Originally Posted by zenkicpe

Tip on burping air out of your system..
Pull your car up on ramps or put blocks under the front tires or park on a decent incline so that the radiator is the highest point. Find a funnel that will fit snugly into the radiator neck. Fill funnel about half way up with coolant. Start car and let idle, the air will burp up and out of the funnel as it works it way around to the radiator. Massage the radiator hoses at it warms and blips the throttle every now and then.

They also make a tool that you attach to the radiator that pressurizes the system pushing all the coolant out then you can basically vacuum in your new coolant.

KAT-PWR · 03-17-2016, 07:50 AM

This is by far the best tool I've used

03-21-2016, 07:25 AM

--Deleted--

03-16-2016, 11:03 PM	#1
kyral Zilvia Junkie Join Date: Nov 2012 Location: wisconsin Age: 33 Posts: 450 Trader Rating: (7) Rides Gallery: kyral Feedback Score: 7 reviews	SR heats up at idle, cools while driving I have an SR that heats up at idle and keeps climbing but when i i get moving it starts cooling down. i dont think its a warped head or headgasket issue because itcools itself back down and the coolant doesnt geyser out of the rad cap when i open it has an aluminum rad and a FMIC I read it might be a clogged cooling system, air in the system, a half stuck thermostat or my cooling fans. im gonna get a coolant flush. i tried to bleed the air today but i might not have done it right (removed the bleeder screw by the exhaust side of engine) anyone got any input on this?

03-16-2016, 11:29 PM	#2
jr_ss Post Whore! Join Date: Dec 2005 Location: Pa Posts: 6,415 Trader Rating: (35) Feedback Score: 35 reviews	Are your fans working? They all heat up at idle, but usually a radiator fan/s turn on you cool them off. __________________ My SR20VET Does your VTC gear rattle in your S14/15 SR? PM me.

03-17-2016, 06:20 AM	#3
hanzbrady Zilvia FREAK! Join Date: Apr 2015 Location: Floriduh Posts: 1,166 Trader Rating: (4) Feedback Score: 4 reviews	You have air in your system, I'd assume that if you revved your car at idle it'd probably cool down as well. My car had the same issue and it turned out to be a cracked coolant line under my intake __________________ [email protected]

03-17-2016, 07:50 AM	#6
KAT-PWR Nissanaholic! Join Date: Dec 2011 Location: US Posts: 2,040 Trader Rating: (11) Rides Gallery: KAT-PWR Feedback Score: 11 reviews	This is by far the best tool I've used __________________ MRP Manufacturing

03-21-2016, 07:25 AM	#7
Tucker240 Guest Posts: n/a	--Deleted-- Last edited by Tucker240; 03-17-2019 at 11:45 PM..

03-17-2016, 06:32 AM	#4
zenkicpe Zilvia Member Join Date: Apr 2015 Location: NEPA Age: 44 Posts: 267 Trader Rating: (1) Feedback Score: 1 reviews	Tip on burping air out of your system.. Pull your car up on ramps or put blocks under the front tires or park on a decent incline so that the radiator is the highest point. Find a funnel that will fit snugly into the radiator neck. Fill funnel about half way up with coolant. Start car and let idle, the air will burp up and out of the funnel as it works it way around to the radiator. Massage the radiator hoses at it warms and blips the throttle every now and then.