overheating KA - blown heater core - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

M11's · 08-30-2010, 02:21 AM

My heater went out before the summer started and since my coolant has been overheating. I have bled it numerous times with no positive results and replaced the t-stat last week, water pump is less than 500 miles old. Would the bad heater motor cause overheating or less coolant circulation? Am running dual efans on high speed constantly can't think of what else to do.

endlessboost · 08-30-2010, 02:19 PM

Loop the heater hose lines, rebleed, and see if it still overheats. That'll basically help you tell if its motor related or heater related. Also, check the coolant temp sensors are properly working.

M11's · 08-30-2010, 06:37 PM

which heater hoses, the one running through the firewall. everything for cooling in the engine is new like i said as is the sensors.

DreamN · 08-30-2010, 07:26 PM

Yes the ones that run to the firewall.

Just loop them and do as mentioned in the other post.

M11's · 09-02-2010, 05:43 PM

so looped the lines and bled it for a while. still overheated after a while of idling. So it must then the the cause of the heater? any good write ups on changing that.

pacotaco345 · 09-02-2010, 09:51 PM

Quote:

Originally Posted by M11's

so looped the lines and bled it for a while. still overheated after a while of idling. So it must then the the cause of the heater? any good write ups on changing that.

If you looped the lines that means you bypassed the heater core.. so it can't possibly be the heater. Check coolant temp sensor, thermostat, etc. I'd just leave the heater lines looped for now seeing that it's the middle of summer.

M11's · 09-12-2010, 04:11 PM

all parts are new like the sensor and pump and have no coolant leaks anywhere. I have ran the engine over with radiator open to release air two days in a row, heating the motor up, cooling, heating etc. Air still bubbles out and even a 10 min trip anywhere with fill the radiator res. with bubbling water.

Mangudai · 09-12-2010, 06:41 PM

You sure you're getting all the air out? Does a steady stream of coolant come out of the bleeder hole?

M11's · 09-12-2010, 06:52 PM

what point should i open that. after the thermostat opens?

*fliprayzin240sx* · 09-13-2010, 06:03 AM

Bleed the system properly, sounds like you still have air in the system. How exactly are you bleeding the system? Also, once the engine is warmed up, do you hear any hissing or steam coming from anywhere, specially under the intake manifold?

Pignose Slider · 09-13-2010, 08:55 PM

If you hear a hissing sound while the car is on what does that mean. After my re-build it started doing that and the engine bay gets really hot.

M11's · 09-24-2010, 02:47 PM

Quote:

Originally Posted by fliprayzin240sx

Bleed the system properly, sounds like you still have air in the system. How exactly are you bleeding the system? Also, once the engine is warmed up, do you hear any hissing or steam coming from anywhere, specially under the intake manifold?

Have been running the motor with radiator cap off and funnel in. letting motor warm up air bubble out. done it few times with the bleeder valve open and funnel in the radiator also. issue has been getting worse

endlessboost · 09-24-2010, 03:01 PM

Quote:

Originally Posted by M11's

Have been running the motor with radiator cap off and funnel in. letting motor warm up air bubble out. done it few times with the bleeder valve open and funnel in the radiator also. issue has been getting worse

Sounds like a blown headgasket pressurizing the coolant system. Do a leak down test, that'll help determine whether it's a blown headgasket or something else. Have you pressurized the system yet to see if there's an external leak?

M11's · 09-24-2010, 03:15 PM

wouldn't it stubble at all if it were the head gasket. since it began over heating like this there was the first traces of 'milk' on the dip stick but was such a little amount didn't connect that to the cooling problem

endlessboost · 09-24-2010, 03:29 PM

Quote:

Originally Posted by M11's

wouldn't it stubble at all if it were the head gasket. since it began over heating like this there was the first traces of 'milk' on the dip stick but was such a little amount didn't connect that to the cooling problem

Yep it's a blown headgasket. Sorry bud, good luck with the rebuild.

RyanS13 · 09-24-2010, 04:09 PM

Yea thats the exact issue my car was having a couple months ago. It would just keep getting air in the cooling system no matter how many times I bled it.

The head gasket blew and was it was leaking air from the cylinders into the coolant system.

Changing the head gasket is a fairly easy job. Just take your time. The hardest part is to keep the engines timing and stuff all correct when your doing it.

*Wake* · 09-24-2010, 04:12 PM

second that.

08-30-2010, 02:21 AM	#1
M11's Zilvia Junkie Join Date: Nov 2009 Location: Liberty Lake, Wa Age: 30 Posts: 334 Trader Rating: (1) Feedback Score: 1 reviews	overheating KA - blown heater core My heater went out before the summer started and since my coolant has been overheating. I have bled it numerous times with no positive results and replaced the t-stat last week, water pump is less than 500 miles old. Would the bad heater motor cause overheating or less coolant circulation? Am running dual efans on high speed constantly can't think of what else to do. __________________ WELCOME TO THE SHITTY WOK

08-30-2010, 06:37 PM	#3
M11's Zilvia Junkie Join Date: Nov 2009 Location: Liberty Lake, Wa Age: 30 Posts: 334 Trader Rating: (1) Feedback Score: 1 reviews	which heater hoses, the one running through the firewall. everything for cooling in the engine is new like i said as is the sensors. __________________ WELCOME TO THE SHITTY WOK

08-30-2010, 07:26 PM	#4
DreamN Post Whore! Join Date: Nov 2006 Location: SoCal - 818 Age: 36 Posts: 10,691 Trader Rating: (54) Rides Gallery: DreamN Feedback Score: 54 reviews	Yes the ones that run to the firewall. Just loop them and do as mentioned in the other post. __________________ - Jimmy Wanted: TBD For Sale: TBD

09-02-2010, 05:43 PM	#5
M11's Zilvia Junkie Join Date: Nov 2009 Location: Liberty Lake, Wa Age: 30 Posts: 334 Trader Rating: (1) Feedback Score: 1 reviews	so looped the lines and bled it for a while. still overheated after a while of idling. So it must then the the cause of the heater? any good write ups on changing that. __________________ WELCOME TO THE SHITTY WOK

09-12-2010, 04:11 PM	#7
M11's Zilvia Junkie Join Date: Nov 2009 Location: Liberty Lake, Wa Age: 30 Posts: 334 Trader Rating: (1) Feedback Score: 1 reviews	all parts are new like the sensor and pump and have no coolant leaks anywhere. I have ran the engine over with radiator open to release air two days in a row, heating the motor up, cooling, heating etc. Air still bubbles out and even a 10 min trip anywhere with fill the radiator res. with bubbling water. __________________ WELCOME TO THE SHITTY WOK

08-30-2010, 02:19 PM	#2
endlessboost Zilvia Junkie Join Date: Jul 2008 Location: central jerz Posts: 316 Trader Rating: (13) Feedback Score: 13 reviews	Loop the heater hose lines, rebleed, and see if it still overheats. That'll basically help you tell if its motor related or heater related. Also, check the coolant temp sensors are properly working.

09-12-2010, 06:41 PM	#8
Mangudai Zilvia Addict Join Date: Jan 2007 Location: South Posts: 656 Trader Rating: (0) Feedback Score: 0 reviews	You sure you're getting all the air out? Does a steady stream of coolant come out of the bleeder hole? __________________ Almost there.

09-12-2010, 06:52 PM	#9
M11's Zilvia Junkie Join Date: Nov 2009 Location: Liberty Lake, Wa Age: 30 Posts: 334 Trader Rating: (1) Feedback Score: 1 reviews	what point should i open that. after the thermostat opens? __________________ WELCOME TO THE SHITTY WOK

09-13-2010, 06:03 AM	#10
fliprayzin240sx Man w/ CTSV & a Car Seat Join Date: Aug 2002 Location: Tampa Posts: 17,998 Trader Rating: (19) Rides Gallery: fliprayzin240sx Feedback Score: 19 reviews	Bleed the system properly, sounds like you still have air in the system. How exactly are you bleeding the system? Also, once the engine is warmed up, do you hear any hissing or steam coming from anywhere, specially under the intake manifold? __________________ If you think Zilvia has too many assholes... CLICK HERE!!!

09-13-2010, 08:55 PM	#11
Pignose Slider Join Date: Sep 2010 Location: rancho cucamonga CA Age: 40 Posts: 14 Trader Rating: (0) Feedback Score: 0 reviews	If you hear a hissing sound while the car is on what does that mean. After my re-build it started doing that and the engine bay gets really hot.

09-24-2010, 03:15 PM	#14
M11's Zilvia Junkie Join Date: Nov 2009 Location: Liberty Lake, Wa Age: 30 Posts: 334 Trader Rating: (1) Feedback Score: 1 reviews	wouldn't it stubble at all if it were the head gasket. since it began over heating like this there was the first traces of 'milk' on the dip stick but was such a little amount didn't connect that to the cooling problem __________________ WELCOME TO THE SHITTY WOK

09-24-2010, 04:09 PM	#16
RyanS13 Zilvia Addict Join Date: Jul 2009 Location: CA Posts: 657 Trader Rating: (14) Feedback Score: 14 reviews	Yea thats the exact issue my car was having a couple months ago. It would just keep getting air in the cooling system no matter how many times I bled it. The head gasket blew and was it was leaking air from the cylinders into the coolant system. Changing the head gasket is a fairly easy job. Just take your time. The hardest part is to keep the engines timing and stuff all correct when your doing it. __________________

09-24-2010, 04:12 PM	#17
Wake Premium Member Join Date: Dec 2003 Location: Santa Cruz, ca Age: 38 Posts: 6,699 Trader Rating: (8) Feedback Score: 8 reviews	second that. __________________ S.P.P.S. Member #00 CoUpe LOve Member #00

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