S14 chassis (redtopSR20) heater Hose Route

[MrFairlady]

Need some help.
No Heat after trying Multiple diff Things.

Posted in 2-3 diff areas of the forum and Searched Everywhere, and No one shows how to Route S14 heater hoses with a Red/Blk top Sr20. Only S13's and a friend has a S14 Sr20's in his S14 that are routed diff since the manifold is Diff.

Which hose to heater Core Goes where?
I routed mine Similar to my S13 with the same engine but for some reason I had heat at 1 point and It now Does not work.
Car also wouldn't quite get to normal Operating Temp (61degrees Cel) so My car is over-cooling or I thought the Thermo was staying Open, untill I changed Thermostats yesterday, back to OEM and re-bled system 2-3 times before that & again. Finally its running at 81degree's Cel with cardboard in front of rad/condenser area also.

help.

rear heater hoses not getting hot (Update: they get hot now**) and Don't seem to hold pressure like the Front rad hoses do.
-Checked heater valve
-Swapped from Nismo Thermo to OEM
-Checked Fuses and all servo Motors
-Stock Clutch fan and Shroud

[MrFairlady]

no one has a Redtop swapped SR in thier S14?
come on guys.

I tried Swapping hoses around and Still same result.NO Heat.
Though-top and bottom hoses since I swapped them around both Get hot now and only 1 did before I swapped them. Still not a Glimpse of heat.

[laocivic]

its pretty straightforward..have you checked the car to see if everything is in order as far as heating goes?

[jr_ss]

Honestly, after reading through your no heat thread, I'm convinced it's in your cabin where the issue lies. There is a blend door, not just that mechanically actuated valve in the engine bay.

[MrFairlady]

its pretty straightforward..have you checked the car to see if everything is in order as far as heating goes?


-I've bled the system 2-3 times.Used a Snap on Radi-Kit to perform a vac on the system 1 of those 2 times.

-Checked The heater valve and it works open/close (i guess inside the Pipe - feels like its moving inside) and I checked all servo's to make sure they were working for vents and Air Mix and they are.

-replaced Thermostat the other night with a confirmed working OEM one from the new nismo 1 and thought it was sticking open because the car takes a while to get to operating Temp. same result.

-Swapped Heater hoses around at back of the engine last night, and Now both hoses get warm finally and only 1 would before that, and Still no heat.

-No leaks that I can see - car doesn't Smoke and runs Waaay cooler than It should. Car Now runs Warmer & finally 81 degree's Celcius after swapping thermostats and driving/ideling for a while 20-30mins. So it actually runs very Cool with Stock Clutch fan and Shroud.na dthats even with cardboard in front of the Condenser/radiator area.

-Water pump Is new and was replaced when I installed the engine.


*********Car had heat at 1 point and was driving fine. **********
1 day it just just didn't get warm. Climate here has been freakishly warm and I didn't need heat for a few days and then I went to turn it on and There was Nothing.

[MrFairlady]

Honestly, after reading through your no heat thread, I'm convinced it's in your cabin where the issue lies. There is a blend door, not just that mechanically actuated valve in the engine bay.


thats what I thought!!!!!
no one could confirm that.
I pulled the radio to look all back in there and have no clue where its located.

[holemilk00]

It's really hard to tell here but I went in the garage and snapped a few quick pics before work for you. The first pic is the mix motor. These are taking from the passenger side looking behind the dash and over the trans tunnel.

http://img.photobucket.com/albums/v228/holemilk00/821f2f29.jpg

You've probably already found that. Directly behind the mix motor and further up on the trans tunnel is the blending arm, I can't get you a pic of the actual motor without taking the dash out but I hope you can see it in here so you know where too look. This is almost to the firewall on top of the trans tunnel.

http://img.photobucket.com/albums/v228/holemilk00/2a472516.jpg

You can barely see it in that pic but it's there on the white box. You'll have to take a LOT of your dash out to get to it.

I hope this helps.

Shane

[holemilk00]

There are a set of floor vents between the two pics I took that blow on the passengers feet. If that helps at all.

[MrFairlady]

It's really hard to tell here but I went in the garage and snapped a few quick pics before work for you. The first pic is the mix motor. These are taking from the passenger side looking behind the dash and over the trans tunnel.

You've probably already found that. Directly behind the mix motor and further up on the trans tunnel is the blending arm, I can't get you a pic of the actual motor without taking the dash out but I hope you can see it in here so you know where too look. This is almost to the firewall on top of the trans tunnel.

You can barely see it in that pic but it's there on the white box. You'll have to take a LOT of your dash out to get to it.

I hope this helps.

Shane
Thank you so much.:cool:

So from what I can tell (I never Got that Deep behind it) but it looks like a cable? Similar to the cable that Runs To the engine bay.This must Pull Inside the Heater core??
I wonder if it worked 1 time when I had heat and then Defaulted to Closed and thats why It never Worked again???

Now only other question is - What year is your car? I'm wondering if you have the 96+ and the heater Stuff is Diff. Mines a 95 and has the Stupid Control valve and I guess this one too??

[Om1kron]

yeah without removing your dash to make sure everything is in operating condition you're fucked. I have the same problem and decided to hold out and just buy a 98 cooling system, make a/n hosing adapters and then electronically sort out why the dcc will let me control all of my mode doors, and air speed settings but it wont change the fucking hot to cold. At first only hot air would blow out, and a long long time ago it actually regulated hot and cold but all of those motors down there at some point have just decided to go bad with the death click click click you hear from the cheap nissan shit.

If I had the coin I'd probably take apart every single one of those shitty servo motors and have all of the gears scanned and replicated on a cnc in aluminum and shove em back in the boxes. Now give me a fucking death click trying to change modes you old piece of shit.

[holemilk00]

Mine is a 98 and I had a 95 before this and you're right, there are sim differences but I'm not sure how drastic. I know ^^Om1kron is dealin with the differences right now. I would assume both of them have a blend system it's just how different are they?? With that said you would have to get pretty deep in the dash to diagnosis this problem if it's with the blend motor.

[projectblak]

just take out the dash its really not that hard just tedious i had to take out my dash on the new shell i got and im glad i did because all the boxes were there they were just empty lol i know its not related but it helps. remove glove box, cluster, radio, center console, a pillars, remove bolts/screws and out she comes sounds bad but very easy

[MrFairlady]

Mine is a 98 and I had a 95 before this and you're right, there are sim differences but I'm not sure how drastic. .

Thats what I feared.
I think Your pic may be of the 96+ models but I guess I'll get a chance to Check when I get home.I'll yank the dash If I have to because wouldn't you know...Its 31 degrees this morning and I have no heat. Luckly I'm in a garage so everythings Not Frosted over.

everything I read is how thats what They changed to, instead of the Valve in the engine bay its just a Fitting/port connection in the same location as the valave - INTO the heater core where I guess it does the rest.

Jeeez. what a Pain.

Heater Hose Route - does that Even make a Diff>?>?
It should still blow warm which ever they are Routed Correct? Just kind of a IN and Out right?

I just hope my turbo is getting Coolant.

[1fastssilvia]

the heater core isnt clogged is it? pull both heater hoses and try blowing through it in both hose nipples. would make sense if only one heater hose is hot

[MrFairlady]

the heater core isnt clogged is it? pull both heater hoses and try blowing through it in both hose nipples. would make sense if only one heater hose is hot
very True. I agree.
Chewed my hands up Swapping Heater hoses around last night, but I was doing it from the Motor Side, not the firewall Side.
Coolant came out of the Engine side hoses But I can't say much for the heater core due to the Angle of the Hoses. I cut off the Pipe that Makes the "U" behind the head and have it right next to the other straight pipe that Goes in to the core - getting rid of anything behing the head Like on my Other S13.Eaiser that Way.

though now that I swapped the hoses around they both were warm after Driving it for a Bit.





--History---
vehicle had it all the heater hoses bypassed when I got it from Orig Owner. Not sure why.so it was just Open Pipes from the Firewall IIRC.

*I swapped motors from the orig SR to another one I built up and Then When I went to bleed Coolant with heater on Months ago..Noticed heat Didn't work but did have blower speed and Stuff.

Found the Fuse Blown that Controls the Temp servo in the engine bay so the Valve was Closed off and Bam Fixed it.
Heat Working perfectly on the Night of the NFC Championship game.Super Hot for a Couple days.

then I went to turn it on a couple weeks ago and Just Luke warm...then a few days later Cool/Cold air.

[holemilk00]

the heater core isnt clogged is it? pull both heater hoses and try blowing through it in both hose nipples. would make sense if only one heater hose is hot

That's what I said in the other thread. It sounds like the heater core clogged up.

[1fastssilvia]

a few things...
Is the coolant at level? if not address that first (obviously)
If both hoses are reaching operating temperature, and its still not blowing hot i would start looking at the blend door actuator, these mid 90s nissans are famous for blend door and mode door actuators. is it stuck in one position? does it sweep the full distance? if the opperation of the blend door is erratic replace the blend door actuator. If it dosent move at all, disconnect the connector and back probe, look for power and grounds and input from the control head. If theres no power from the control head, replace the control head. If there is good power and ground replace the blend door. Let me know if you need wiring diagrams/connector views or locations. I can pm or email them to you

Note: make sure that the blend door itself is not stuck. if thats the case you will need to free that up before condeming the blend door actuator.

[holemilk00]

^^are you not reading the thread or do you just like stating the obvious? We've been talking about the blend door and where to find it. He also plainly says that both hoses are NOT getting hot so your statement about both hoses reaching operating temps was already answered. Not trying to be a dick and I'm sure I'm coming off as one anyway but please actually read the thread before saying the same stuff that's already been said or asking questions that have been answered.

[blueshark123]

if you need another heater core pm me but your best bet is to just take out your dash and see what is going on behind there.

[jr_ss]

-Swapped Heater hoses around at back of the engine last night, and Now both hoses get warm finally and only 1 would before that, and Still no heat.

He also plainly says that both hoses are NOT getting hot so your statement about both hoses reaching operating temps was already answered.

Not to be a dick hole, but yeah, he stated both hoses ARE getting warm...

I think you need to check out your blend door actuation and see if anything moves. You know heat worked at one point, so with that said, I'd start at the door and servo. Also, remember the core was bypassed and not capped I'm sure, so chances of shit corroding or being corroded in there are high.

[JonathanPrem]

sorry to thread jack but If the lines are wrong will the heater still work?

[MrFairlady]

thanks guys for all your help thus far but still at square 1.

sorry to thread jack but If the lines are wrong will the heater still work?
Good question. I've been asking the same.Thats what My buddy said about his S13 and a SR. He had to reverse the lines he had to get heat to work.


----update-----

I used a Matco pressure Tester and everything held quite a bit of pressure and i checked the Firewall and 1 hose had a slightly Loose connector and I pulled on it and It spewed a bit. Not a big deal.

***Checked the Servo/blend Door Behind deep behind the dash like "holemilk" advised, and Moved the temp needle back and forth and It moved/sounded perfectly. granted I don't know about inside the Heater core....But I don't think its that.

I'm almost wondering If its the coolant I'm using. This is the 3rd SR swap and I've always used toyota Red Coolant since I work at lexus and Its Awesome Stuff, and I'm going to try to Drain it all again...Change to Distilled water and water wetter and maybe Blow out the Heater Core to see if it all Flows this weekend I guess. No other idea what it could be at this point.

Still Stuck. Def could use the engine to Run Hotter though.

[jr_ss]

I would hook up a hose to one side and see if you can visibly flush water through the core... It would atleast let you know if it's clogged or not.

[MrFairlady]

I would hook up a hose to one side and see if you can visibly flush water through the core... It would atleast let you know if it's clogged or not.

Un hooked the Bottom Hose from the Core to the engine and It pointed to the Ground and Used the pressure tester and applied some pressure to the System and Coolant Poured out. So...I have a feeling its Pretty Free Flowing.

FML

[MrFairlady]

*update*

After my 15-20 min drive to work, I checked the Temps and The gauge in the Upper hose Read 56 degrees (which Took that amount of time to get to that temp - WIth a smallpeice of cardboard between the Condensor and radiator This time)
***halfway through my Drive I turn the heater on and Cold air was coming out.

I Turned heat on when I pulled in my parking Spot and heat blew Warm/Hot for a sec or 2, and the more fan speed I raised it to it started getting colder untill it was cool air. Not warm. :(

My Factory Gauge since the Thermostat replacement does read a tad higher now Than it use to sit on the needle for sure. But still no idea what the deal is.


------------------------------------------------------
Setup:
SR20 2871,cams,FMIC and Running all A/C components (condenser in the front Bumper) etc
Alum Radiator with Stock Clutch fan and Shroud and a/c fan installed.
Toyota Red 50/50 coolant
10w40 oil Non-syn

What Could I do to get the engine to Run Hotter? Switch Coolant??

[Big Zee]

I don't see what the difference in Coolant could be, I always used the green stuff though as thats what Nissan recommended.

try blowing out your heater core. someone could have put a radseal product in and it jammed up.

hook up 2 longer hoses to the firewall connectors on your heater core and the hoses extend out of your engine bay a fair amount. put one hose in an empty bucket.
install a garden tap ffemale end on the other one and attach a garden hose

turn on water and see if it comes out of the hose under any sort of pressure or if its clean ( should be red but you know what I mean, no chucks of silver goo, or rusty coolant )

it sounds like a bunk heater core to me. it is 15 years old if its still the factory one.

[MrFairlady]

What I noticed at lunch today - temp outside is around 58
is after driving for a little bit and stopping to get gas - car's temp gauge on the PBM Meter read 60 Celcius which at that point HEAT was trying its hardest to get warm.You could feel it change temp.I revved it and held it at 3-4k and would barley start to get warm.

-Got out felt both heater hoses and they were Hot.
-Both rad hoses Were Hot also.
car just would not get above that temp - SO either:
A: car will only get but so hot
B: temp Sender on Parts Shop Max needs to possibly be calibrated
c: Coolant Just not quite Hot enough + heater core Flow issue maybe?


What I don't understand is,is the Top radiator Hose flow coming out of the rad pass through it 1st? or from the Engine and passing through it.

That Sensor Takes quite a While to get even remotley Warm & read in the 40-50degrees celcius range.

Makes me belive theres just not enough Coolant in the system or its just the Coolant is cold at that level of flow due to the radiator and Finally gets flowing but the gauge Still reads 43 degrees or so.

Gonna try to have 1 of the tech's at work bleed my car and see if thats the problem is. I couldn't Fill the coolant anymore when I tried the past 2 times.

[jr_ss]

I have a few ideas... I believe you mentioned you still had the mechanical valve in the engine bay? Is there a chance that the arm inside the valve is stripped and is actually closed when showing open? Second, pull you blend door arm off and prop it completely open and see if you get heat then. I'm still convinced the problem lies inside the car.

[MrFairlady]

I have heat now. It's hot but not the hottest in the world but got it.

I disco the top hose. Made a hose so I could disco the lower hose and flush it hrough with coolant. Noticed it didn't want to take so I spun the valve and boom fluid pushed through.

So,.....it looks like the servo is telling it to close off coolant instead of open it. I noticed the cable had a slight kink in it but when I set the tEmp to full hot the cable is supposed to get longer and open it is the way it's working and cld pulls the cable tighter.
Well unless anyone can confirm that for me...it's reversed all of a sudden. But the servo works????

So I blew air through it and the same red coolant came out so i have no internal issues im sure and even filled it with coolant and plum everything back up.
Went for a drive and bam..heat!!!!

If anyone gets a chance out of curiosity please check to see what your cable does jwhen you go hot to cold. It gets cool with the blend servo and the engine valve cable disconnected so I know that's working also after all this.

May need a new cable but I'm fine with setting it and leaving it. Now gotta charge a/c and get that going since it was of course 70 today. Hope that goes smooth. ...........

Thanks everyone for your help. Love this forum!

[Om1kron]

Where is this said cable, I've never noticed one back when I had manual controls for my hot and cold (pre dcc) and always wondered where the fuck that shit was.

As far as an engine bay fuse that someone else mentioned to control hot and cold, it's been a while since I spec'd out my dashboard fusebox, there was a blue/red wire in question I thought was supposed to handle power for my windows but that may very be the power for the valve. It's not super important to me to get that up and running but I'll have to look into it when I replace the fuse box.

[MrFairlady]

On the 95's it's on the heater hose and bolts to the firewall. Valve is in the middle of the hose where it enters the engine.it Has a throttle cable that goes into the cabin near the throttle cable also and the servo pulls and pushes it for coolant flow or no flow.
I think 96 it changed to something more on the inside of the car.

Mines unhooked and I flipped the temp to cold today to check it once my heat was on and it got cold still. Even with the cable detached.
I guess it might have more to do with a/c than just heat.clearly.otherwise i dont see why its there .I still need to charge my ac so I hope it goes well also.
----------------------------------------------------------
What's funny is I've read what your going through on your dcc install and that's why I'm making sure everything works now,is because I have a dcc to install as well. I don't care about auto shit bu the fact it looks so much better than the ghetto eom one is why I'm doing it.

As long as it switches vents and temp I'm fine. I don't have any of the sensors just the unit and some pigtails for it to wire it in.
I've done 3 s13 dcc's but the s14 is clearly the most trivial from what I've read of everyone's.

[MrFairlady]

WELP...nevermind. No heat again!!!

Was working fine yesterday and I didn't change a thing and now its blowing cool again.

Going to Remove the Heater valve this weekend and Throw it away. No point in it other than I'm sure a/c so I think That and maybe STill the routing of the hoses could be suspect, since I'm not sure which is which....is the problem.

[projectblak]

If u throwaway that open and close valve that's connected to the line don't, I tried buying a new one and couldn't find one so just a heads up

[MrFairlady]

On my Drive to lunch - I'm in the car for maybe 5 mins (temp out side is mid 60's today) - Water temp reads 115F,..Check the Heat & it's Blowing me out the car is so hot!! WTF.

So clearly it has something to do with Outside temp.
Yes I could be my Alum radiator is overkill at some degree....but This morning (outside temp maybe: 43-44 degrees) with a reading of 136F on my water temp it was "cooler than the other side of the pillow".

I'm about Fucking Done with this.

Anyone Know what the weird Temp sensor up front near the radiator/Core Support is For? A/c Mainly I'm guessing.
ALL nissans have them (including my old 91 and my 90 that I removed) and its clearly some type of Ambient Temp sensor,but why since theres No Auto Climate or anything??

[jr_ss]

The one infront of the evap/rad is your outside air temp sensor... I wouldn't think your aluminum rad, would have anything to do with it. I have a Koyo and never had an issue with heat in my car...

[MrFairlady]

The one infront of the evap/rad is your outside air temp sensor... I wouldn't think your aluminum rad, would have anything to do with it. I have a Koyo and never had an issue with heat in my car...
AGREED

If it was overcooling than the thermostat would adjust accordingly.
I'm going to remove the hose and the Valve and Bypass it all and see what happens.Could Maybe still be a bubble in these hoses.

I just Still wonder in the FLOW of the SR20 which hose should go to which Heater port. That Could Have a little to do with it maybe??

Crazy that when I don't need heat....its how as hell.:facepalm:

[jr_ss]

If I was at home and had access to my FSM I could give you a better idea of what hose goes where

[MrFairlady]

If I was at home and had access to my FSM I could give you a better idea of what hose goes where
no Worries...when you get a chance please do.You've been a Big help with just ideas alone.

The S14 manifold has 2 ports side by side down low on the mani, and are very short going to the Heater core and the Valve (after looking at a friends 95 S14 & S14SR)

The Typical S13 Route is: Top hose normally makes a "U" behind the head back to Top port of the heater core, and bottom hose (using a twisty Hose) to bottom port.
I ran it like that originally since My engine is a S13 SR matching with my other SR'd S13.

I switched them around a few days ago thinking that might help and of course no change.Now I still want to make sure it even routed correctly.

[jr_ss]

Based on Nissan parts diagrams I've seen it's just a "radiator" if you will, with no specific inlet outlet. But being that I have the exact year and had an S14 SR in my car I should know. I know how my setup is routed with the S14 hoses. I'll see if I can dig up a picture of them.

[jr_ss]

In that picture the outside line, which comes from the water pump/thermo housing area, goes to the top port on my car. The inside line comes from the head and connects to the bottom port. This is how I had it setup with my S14 SR and I never had an issue with heat, not that I have to use it too often being in Florida. Hope that helps.

http://i627.photobucket.com/albums/tt352/jr_ss/blah010.jpg