S14 Heat Not Working - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

chibo · 12-19-2008, 03:16 PM

Alright - bone stock KA, nothing molested.

Looks like it has a new waterpump, new hoses, etc. Everything is hooked up correctly. When I turn on the heat I just get ambient air blowing at me. Probably related is that there is some temperature gauge fluctuation - when I'm engine braking the water temp dips a little, same with WOT up in the rpms.

Am I looking at a dead thermostat? Any other ideas? Thanks.

orion::S14 · 12-19-2008, 03:45 PM

What year?

If it's a '95, it has a cable operated valve on the heater hoses. Look behind the intake manifold...make sure it moves when you slide the temp control to HOT.

If it's '96-98...then you have some other problem.

The temp fluctuation is probably a loose connection at the sender...it's just a spade clip...and that gauge is pretty inaccurate.

- Brian

***S14DB*** · 12-19-2008, 04:33 PM

On the OBDII S14's the valve usually fails open. It should be open, then when you start the car the valve closes. This is to keep the core purged.

Usually what fails is the mixture damper. Slide from hot to cold fast and listen to hear it travel.

chibo · 12-19-2008, 09:35 PM

Ding ding. Thank you guys. I had someone slide it back and forth while I watched/listened and didn't see anything move. It is a 96.

reinvent · 12-19-2008, 09:48 PM

dumb question on the s13 , what does the hot cold switch on interior heater do to change between hot and ambient? i assume hot water always flows through heater core and the switch changed the ducting?

12-19-2008, 03:16 PM	#1
chibo Zilvia FREAK! Join Date: Sep 2005 Location: Tempe and Scottsdale, Arizona Age: 37 Posts: 1,425 Trader Rating: (0) Feedback Score: 0 reviews	S14 Heat Not Working Alright - bone stock KA, nothing molested. Looks like it has a new waterpump, new hoses, etc. Everything is hooked up correctly. When I turn on the heat I just get ambient air blowing at me. Probably related is that there is some temperature gauge fluctuation - when I'm engine braking the water temp dips a little, same with WOT up in the rpms. Am I looking at a dead thermostat? Any other ideas? Thanks. __________________ 1989 S13 \| 1996 S14 \| 2001 E46 \| 2009 ZX6R

12-19-2008, 03:45 PM	#2
orion::S14 Nissanaholic! Join Date: May 2003 Location: Orange Park, FL Posts: 1,666 Trader Rating: (0) Feedback Score: 0 reviews	What year? If it's a '95, it has a cable operated valve on the heater hoses. Look behind the intake manifold...make sure it moves when you slide the temp control to HOT. If it's '96-98...then you have some other problem. The temp fluctuation is probably a loose connection at the sender...it's just a spade clip...and that gauge is pretty inaccurate. - Brian __________________ www.KA24DEvelopment.com

12-19-2008, 04:33 PM	#3
*S14DB* AFC #1 Join Date: Oct 2003 Location: 昨晩あなたのお母さんの家 Posts: 20,181 Trader Rating: (3) Feedback Score: 3 reviews	On the OBDII S14's the valve usually fails open. It should be open, then when you start the car the valve closes. This is to keep the core purged. Usually what fails is the mixture damper. Slide from hot to cold fast and listen to hear it travel. __________________ Comments should be taken as Opinions not as Statements of Fact

12-19-2008, 09:35 PM	#4
chibo Zilvia FREAK! Join Date: Sep 2005 Location: Tempe and Scottsdale, Arizona Age: 37 Posts: 1,425 Trader Rating: (0) Feedback Score: 0 reviews	Ding ding. Thank you guys. I had someone slide it back and forth while I watched/listened and didn't see anything move. It is a 96. __________________ 1989 S13 \| 1996 S14 \| 2001 E46 \| 2009 ZX6R

12-19-2008, 09:48 PM	#5
reinvent BANNED Join Date: Dec 2008 Location: illinois Posts: 104 Trader Rating: (0) Feedback Score: 0 reviews	dumb question on the s13 , what does the hot cold switch on interior heater do to change between hot and ambient? i assume hot water always flows through heater core and the switch changed the ducting?