ka overheating. - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Link · 12-21-2012, 12:56 AM

hey guys. i posted a while back that my motor was overheating with lots of smoke blah blah. anyway, replaced the headgasket, no more smoke. now its leaking coolant (water pump?) and when the gauge gets up to the H, the heat comes out freezing and seems to overheat the motor more lol. if it isnt one thing..anyway, any suggestions? im going to replace the water pump and thermostat soon.

shiftdrift · 12-21-2012, 01:25 AM

the water pump has a valve on it that will leak coolant if the seal is bad. check if it's leaking. also check underneath the intake and see if any of the coolant lines are leaking, they are 20 years old and like to dry rot, so spend plenty of time checking. next inspect your radiator/hoses for cracks/leaks. if the heat comes out freezing you either A. have the heater hoses on wrong or B. have air/debris in the heater core. did you bleed the system good? replace the thermostat and water pump, they're very cheap (20 dollars) to replace. Also, if you're going to be checking under the intake use a good pen flashlight to really look good, maybe even from under the car. mine had a split in the hose above the starter and under the intake and was leaking on the block and evaporating and took forever to track down.

rcdad123 · 12-21-2012, 01:54 AM

sounds like you have air in the cooling system if the heater does not work. the easiest way to bleed the system is to remove the thermostat and drill 2 holes on top about 1/4 inch in diameter. this will make bleeding the cooling system quick and easy. also like shiftdrift said, check all of the hoses. i personally would replace all of them.

shiftdrift · 12-21-2012, 02:01 AM

i wouldn't recommend drilling holes in the thermo, that may work in cali, but not in new jersey haha, I drilled 2 in mine for the same reason and it would NOT hold heat, would instantly drop when i turned the heat on and get cold.

Link · 12-21-2012, 02:52 AM

cool thanks for the replies. anyway, to be more specific, the heat is hot for a little while, then its freezing. and it only leaks when the car is on.

shiftdrift · 12-21-2012, 03:11 AM

it probably only leaks under pressure, so it's probably from a hose that has a small hole in it. sounds like a bad thermostat, or one with holes drilled in it.

240boi115 · 12-21-2012, 04:13 AM

could be a freeze plug my ka24e had the same problem cept the fluid was boiling in the reservoir...

12-21-2012, 12:56 AM	#1
Link Leaky Injector Join Date: Oct 2012 Location: New Jersey Age: 31 Posts: 86 Trader Rating: (1) Feedback Score: 1 reviews	ka overheating. hey guys. i posted a while back that my motor was overheating with lots of smoke blah blah. anyway, replaced the headgasket, no more smoke. now its leaking coolant (water pump?) and when the gauge gets up to the H, the heat comes out freezing and seems to overheat the motor more lol. if it isnt one thing..anyway, any suggestions? im going to replace the water pump and thermostat soon.

12-21-2012, 01:25 AM	#2
shiftdrift Nissanaholic! Join Date: Nov 2009 Location: indiana Age: 31 Posts: 2,242 Trader Rating: (42) Feedback Score: 42 reviews	the water pump has a valve on it that will leak coolant if the seal is bad. check if it's leaking. also check underneath the intake and see if any of the coolant lines are leaking, they are 20 years old and like to dry rot, so spend plenty of time checking. next inspect your radiator/hoses for cracks/leaks. if the heat comes out freezing you either A. have the heater hoses on wrong or B. have air/debris in the heater core. did you bleed the system good? replace the thermostat and water pump, they're very cheap (20 dollars) to replace. Also, if you're going to be checking under the intake use a good pen flashlight to really look good, maybe even from under the car. mine had a split in the hose above the starter and under the intake and was leaking on the block and evaporating and took forever to track down. __________________ SW Fab

12-21-2012, 02:01 AM	#4
shiftdrift Nissanaholic! Join Date: Nov 2009 Location: indiana Age: 31 Posts: 2,242 Trader Rating: (42) Feedback Score: 42 reviews	i wouldn't recommend drilling holes in the thermo, that may work in cali, but not in new jersey haha, I drilled 2 in mine for the same reason and it would NOT hold heat, would instantly drop when i turned the heat on and get cold. __________________ SW Fab

12-21-2012, 03:11 AM	#6
shiftdrift Nissanaholic! Join Date: Nov 2009 Location: indiana Age: 31 Posts: 2,242 Trader Rating: (42) Feedback Score: 42 reviews	it probably only leaks under pressure, so it's probably from a hose that has a small hole in it. sounds like a bad thermostat, or one with holes drilled in it. __________________ SW Fab

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12-21-2012, 01:54 AM	#3
rcdad123 Zilvia Addict Join Date: Jul 2011 Location: san diego Posts: 639 Trader Rating: (0) Feedback Score: 0 reviews	sounds like you have air in the cooling system if the heater does not work. the easiest way to bleed the system is to remove the thermostat and drill 2 holes on top about 1/4 inch in diameter. this will make bleeding the cooling system quick and easy. also like shiftdrift said, check all of the hoses. i personally would replace all of them.

12-21-2012, 02:52 AM	#5
Link Leaky Injector Join Date: Oct 2012 Location: New Jersey Age: 31 Posts: 86 Trader Rating: (1) Feedback Score: 1 reviews	cool thanks for the replies. anyway, to be more specific, the heat is hot for a little while, then its freezing. and it only leaks when the car is on.

12-21-2012, 04:13 AM	#7
240boi115 Zilvia FREAK! Join Date: Sep 2012 Location: Torrance Age: 28 Posts: 1,486 Trader Rating: (6) Feedback Score: 6 reviews	could be a freeze plug my ka24e had the same problem cept the fluid was boiling in the reservoir...