heater problem HELP! - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

surge s14 · 01-17-2007, 04:11 PM

yeah my a/c blasts but my heater dosnt get hot at all anyone know why?

*ManoNegra* · 01-17-2007, 04:24 PM

Hard to say, dirty or maybe clogged. Would have to remove the dash and dig the heater core out to say for sure but that's a royal p.i.t.a.

D1GP · 01-17-2007, 04:49 PM

what is your temp gauge reading? is the motor getting warm at all? things you may want to look at before tearing the dash out is thermostat, radiator cap, and coolant overflow (make sure it is not cracked).

also check the hoses that run to the heater core and make sure both of them are warm to the touch (located on passenger side firewall).

i had a similar problem where my motor would not get warm and would require much punishing before it hit the half way mark. if i let it idle for a bit, it would fall back down to 1/3 of the gauge and blow cool air. i flushed the coolant, replaced the thermostat, and replaced my cracked overflow. heat gets warm now but still not as hot as i would like it to be but it is better then no heat for the winter. i will probably funk with the heater core come spring.

surge s14 · 01-18-2007, 02:50 AM

Quote:

Originally Posted by D1GP

what is your temp gauge reading? is the motor getting warm at all? things you may want to look at before tearing the dash out is thermostat, radiator cap, and coolant overflow (make sure it is not cracked).

also check the hoses that run to the heater core and make sure both of them are warm to the touch (located on passenger side firewall).

i had a similar problem where my motor would not get warm and would require much punishing before it hit the half way mark. if i let it idle for a bit, it would fall back down to 1/3 of the gauge and blow cool air. i flushed the coolant, replaced the thermostat, and replaced my cracked overflow. heat gets warm now but still not as hot as i would like it to be but it is better then no heat for the winter. i will probably funk with the heater core come spring.

it reads 1/2 way

D1GP · 01-18-2007, 10:50 AM

Quote:

Originally Posted by surge s14

it reads 1/2 way

ok then. check the hoses that run to the core. if only one is cold, then a valve is stuck.

benjiholt · 01-17-2007, 05:49 PM

Just my 2 cents but you sure the heater valve is opening? Don't know if that will be the problem but it's worth checking

surge s14 · 01-18-2007, 02:44 AM

where might that be?

benjiholt · 01-18-2007, 05:37 PM

hey it's just behind the intake manifold on the passenger side right at the firewall i think it's a 3/4 heater hose there will be a little valve in the hose that lets the hot water get into the heater core. There is also a small wire on the valve that actually pulls it open so cgeck and make sure that it's hooked up also.

ispypsi · 01-18-2007, 07:05 PM

later model s14's the valve isnt on the hose, its built into the core. but you can see where the valve used to be as there is still a plastic fitting on there.

either the valve is stuck or the motor for it crapped out. this is the motor that simply opens and closes it when you slide the air mix on the hvac controls (the blue to red slide)

benjiholt · 01-21-2007, 11:17 AM

mines a 95 S14 and the valve is in the hose I saw yours was a95 so I guess yours should be in there also but hey I coul be wrong

g6civcx · 01-21-2007, 05:59 PM

Orginal poster, please answer the following questions for more specific answers?

1) Year/make/model

2) After driving for a while, open the hood. Are the radiator hoses warm to the touch?

3) Do you detect a sweet smell inside or outside the car near the firewall area?

4) Did you bleed your coolant system properly, including the heater core?

Assuming the engine is running properly and there is no leak, the most common causes of cold heater are as follows:

a) Air pockets trapped in the heater core. You need to let the car run and slowly loosen the upper heater hose and bubbles will gush out, indicating that air is purging. Also bleed the bolt on the upper radiator hose outlet on the engine.

b) Clogged heater core. If this is the case, the only way to know is to open up the dash and remove the defective core. Then replace with a new core. This usually happens when you don't use distiled water. Tap water and old coolant rust out the inside of the heater core.

c) Broken aircock valve. This is located on the heater core itself in 240s.

01-17-2007, 04:11 PM	#1
surge s14 Zilvia FREAK! Join Date: Dec 2005 Location: Laredo Texas Posts: 1,125 Trader Rating: (12) Feedback Score: 12 reviews	heater problem HELP! yeah my a/c blasts but my heater dosnt get hot at all anyone know why? __________________

01-18-2007, 02:44 AM	#7
surge s14 Zilvia FREAK! Join Date: Dec 2005 Location: Laredo Texas Posts: 1,125 Trader Rating: (12) Feedback Score: 12 reviews	where might that be? __________________

01-18-2007, 07:05 PM	#9
ispypsi Leaky Injector Join Date: Jul 2005 Location: FL Age: 42 Posts: 97 Trader Rating: (0) Feedback Score: 0 reviews	later model s14's the valve isnt on the hose, its built into the core. but you can see where the valve used to be as there is still a plastic fitting on there. either the valve is stuck or the motor for it crapped out. this is the motor that simply opens and closes it when you slide the air mix on the hvac controls (the blue to red slide) __________________ 97 240sx ka-t. 12.8 @ 108mph. for sale $8K in Florida. 08 mazdaspeed 3. faster + quieter = sleeper.

01-17-2007, 04:24 PM	#2
ManoNegra Guild of Skullduggerous Intent Join Date: Jan 2004 Location: Socal Posts: 7,841 Trader Rating: (48) Feedback Score: 48 reviews	Hard to say, dirty or maybe clogged. Would have to remove the dash and dig the heater core out to say for sure but that's a royal p.i.t.a.

01-17-2007, 04:49 PM	#3
D1GP Zilvia Junkie Join Date: Apr 2004 Location: SLC, UT Posts: 378 Trader Rating: (1) Feedback Score: 1 reviews	what is your temp gauge reading? is the motor getting warm at all? things you may want to look at before tearing the dash out is thermostat, radiator cap, and coolant overflow (make sure it is not cracked). also check the hoses that run to the heater core and make sure both of them are warm to the touch (located on passenger side firewall). i had a similar problem where my motor would not get warm and would require much punishing before it hit the half way mark. if i let it idle for a bit, it would fall back down to 1/3 of the gauge and blow cool air. i flushed the coolant, replaced the thermostat, and replaced my cracked overflow. heat gets warm now but still not as hot as i would like it to be but it is better then no heat for the winter. i will probably funk with the heater core come spring.

01-17-2007, 05:49 PM	#6
benjiholt Join Date: Dec 2003 Location: South West Georgia Age: 46 Posts: 5 Trader Rating: (0) Feedback Score: 0 reviews	Just my 2 cents but you sure the heater valve is opening? Don't know if that will be the problem but it's worth checking

01-18-2007, 05:37 PM	#8
benjiholt Join Date: Dec 2003 Location: South West Georgia Age: 46 Posts: 5 Trader Rating: (0) Feedback Score: 0 reviews	hey it's just behind the intake manifold on the passenger side right at the firewall i think it's a 3/4 heater hose there will be a little valve in the hose that lets the hot water get into the heater core. There is also a small wire on the valve that actually pulls it open so cgeck and make sure that it's hooked up also.

01-21-2007, 11:17 AM	#10
benjiholt Join Date: Dec 2003 Location: South West Georgia Age: 46 Posts: 5 Trader Rating: (0) Feedback Score: 0 reviews	mines a 95 S14 and the valve is in the hose I saw yours was a95 so I guess yours should be in there also but hey I coul be wrong

01-21-2007, 05:59 PM	#11
g6civcx Post Whore! Join Date: Apr 2004 Location: Virginia, USA Posts: 5,764 Trader Rating: (5) Feedback Score: 5 reviews	Orginal poster, please answer the following questions for more specific answers? 1) Year/make/model 2) After driving for a while, open the hood. Are the radiator hoses warm to the touch? 3) Do you detect a sweet smell inside or outside the car near the firewall area? 4) Did you bleed your coolant system properly, including the heater core? Assuming the engine is running properly and there is no leak, the most common causes of cold heater are as follows: a) Air pockets trapped in the heater core. You need to let the car run and slowly loosen the upper heater hose and bubbles will gush out, indicating that air is purging. Also bleed the bolt on the upper radiator hose outlet on the engine. b) Clogged heater core. If this is the case, the only way to know is to open up the dash and remove the defective core. Then replace with a new core. This usually happens when you don't use distiled water. Tap water and old coolant rust out the inside of the heater core. c) Broken aircock valve. This is located on the heater core itself in 240s.