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Where under the hood is the heater inlet pipe?
Posted: Fri Mar 18, 2022 10:47 pm
by palmerwmd
Where under the hood is the heater inlet pipe?
Is it only an issue on the V6s?
Also is it under pressure just like radiator hoses?
or is there some kind of pressure step down inside?
I am trying to figure out if a failure of this part ( or other heating hoses would leave me stranded with an empty cooling system or just w/o heat...
Re: Where under the hood is the heater inlet pipe?
Posted: Sat Mar 19, 2022 1:50 am
by ShipFixer
Along the top of the firewall, and it goes down on the passenger side towards the pipes that carry coolant to the rear passenger heater core.
Re: Where under the hood is the heater inlet pipe?
Posted: Sat Mar 19, 2022 4:32 am
by VStar650CL
palmerwmd wrote: ↑Fri Mar 18, 2022 10:47 pm
Also is it under pressure just like radiator hoses?
or is there some kind of pressure step down inside?
I am trying to figure out if a failure of this part ( or other heating hoses would leave me stranded with an empty cooling system or just w/o heat...
Yes, the whole system runs at the same pressure. Coolant is coolant. If it's leaking, it will eventually overheat the engine no matter what part of the system it's leaking from. However, small leaks in the heater hoses or core will empty the system more slowly than leaks on the engine side, simply because they're high up in the system relative to the block, radiator, and water pump.
Re: Where under the hood is the heater inlet pipe?
Posted: Sat Mar 19, 2022 3:57 pm
by smj999smj
If you look at where the heater core pipes exit the firewall on the passenger side of the engine compartment, the inlet side is on the passenger side and the outlet side is on the driver's side of the two pipe extensions. It's kind of a moot point, because the heater pipe is sold as an assembly with both the inlet and outlet sides, Nissan # 92408-ZS20A. They experience the same problem as the heater pipes on the V6 models; part of it is made out of plastic which gets brittle and breaks after about 10-years or 200,000 miles, give or take.
Re: Where under the hood is the heater inlet pipe?
Posted: Sat Mar 19, 2022 7:36 pm
by palmerwmd
Isn't there an improved aftermarket part somewhere I can put on to get put on?
Or they only made improved part for the V6?
So for my V8, I need to order 92408-ZS20A and have that installed?
Re: Where under the hood is the heater inlet pipe?
Posted: Sun Mar 20, 2022 1:01 pm
by smj999smj
palmerwmd wrote: ↑Sat Mar 19, 2022 7:36 pm
Isn't there an improved aftermarket part somewhere I can put on to get put on?
Or they only made improved part for the V6?
So for my V8, I need to order 92408-ZS20A and have that installed?
Well, the V6 is different in that the inlet and outlet sides are two different pieces. Also, there are "with rear heat" and "without rear heat" options. I don't know of any options for the V8 Pathfinders, which all probably had rear heat or so I would think? The only option I know of for the V8 w/ rear heat is the genuine Nissan part (outside of doing some kind of rig job). On the V6 Pathfinder w/ rear heat, I did see one that was all metal, but I believe the metal pipes that go to the hoses at the bottom of the engine compartment were a little short. Otherwise, all of the aftermarket replacements appear to be made with the plastic parts just like the genuine Nissan part.
It's the R51's with V6 and without rear heat, along with Frontiers and Xterras, that got the updated parts. The inlet and outlet sides are sold separately. The inlet side got a metal part instead of plastic and is sold by a couple of companies, like Dorman and AC Delco. Z1 makes a more expensive one that has an air bleed built into it. For the long pipe, which is the outlet side, Dorman makes an all-metal heater pipe.
Re: Where under the hood is the heater inlet pipe?
Posted: Sun Mar 20, 2022 4:37 pm
by palmerwmd
I have rear heat.
So my part # is different?
Maybe I wont even need an improved part then?
Re: Where under the hood is the heater inlet pipe?
Posted: Sun Mar 20, 2022 4:58 pm
by smj999smj
Your part number is different because the design of the V8 heater pipes is different than the V6, but it still uses the same type of plastic parts that are prone to getting brittle and breaking over time.
Re: Where under the hood is the heater inlet pipe?
Posted: Mon Mar 21, 2022 9:35 pm
by bozoneX
I replaced the plastic tee with brass and deleted the redundant fitting on my X, haven't touched the Pathfinder yet, but mine doesn't have rear heat so it looks to be the same. It seems like a good idea when you get to a certain age where you notice the hoses looking dry and maybe cracking a tiny bit. Then do all the nearby hoses, plastic tee, and PCV at the same time.
Re: Where under the hood is the heater inlet pipe?
Posted: Mon Mar 21, 2022 10:31 pm
by palmerwmd
bozoneX wrote: ↑Mon Mar 21, 2022 9:35 pm
I replaced the plastic tee with brass and deleted the redundant fitting on my X, haven't touched the Pathfinder yet, but mine doesn't have rear heat so it looks to be the same. It seems like a good idea when you get to a certain age where you notice the hoses looking dry and maybe cracking a tiny bit. Then do all the nearby hoses, plastic tee, and PCV at the same time.
Seems like a good approach!
Re: Where under the hood is the heater inlet pipe?
Posted: Wed Mar 23, 2022 2:41 pm
by palmerwmd
I think I fond them on both vehicles.
Things still look pretty solid there.
Re: Where under the hood is the heater inlet pipe?
Posted: Wed Mar 23, 2022 11:10 pm
by smj999smj
palmerwmd wrote: ↑Wed Mar 23, 2022 2:41 pm
I think I fond them on both vehicles.
Things still look pretty solid there.
I hope you didn't just jinx yourself!
Re: Where under the hood is the heater inlet pipe?
Posted: Fri Apr 08, 2022 12:53 am
by donaldpath
Weird
I was messing around with the PCV a couple weekends ago, and in doing so, I ever so sightly nudged the rubber hose that connects to the supposed "inlet" to the heater hose assembly, and the fitting broke clean off.
I went and replaced it with a full metal assembly that I found from watching some YouTube videos on how to swap it out.
Got mine from:
https://www.wholesalepartsexpress.com/p ... -dual-air/
$150 shipped.
Here are some images if the joinery that worried me in regards to the flow of coolant. But I figured a more sturdy build was more important.
I just finished installing it thus past weekend. It's not very fun because of the number of various sized hose clamps I had to deal with; 9 IIRC - and half were in tight spaces. Lots of anxiety and stress was exuded in the replacement.
I would had tried the hack fixes of using plastic fitting to rejoin the broken fitting. But something about using an adhesive that could potentially be exposed to coolant system worried me... Plus if that plastic fitting was so easily broken by such light pressure, I worried the other side of the assembly wouldn't be in any better shape.
Re: Where under the hood is the heater inlet pipe?
Posted: Sun May 22, 2022 5:44 pm
by palmerwmd
donaldpath wrote: ↑Fri Apr 08, 2022 12:53 am
Weird
I was messing around with the PCV a couple weekends ago, and in doing so, I ever so sightly nudged the rubber hose that connects to the supposed "inlet" to the heater hose assembly, and the fitting broke clean off.
IMG_20220327_211400.jpg
I went and replaced it with a full metal assembly that I found from watching some YouTube videos on how to swap it out.
Got mine from:
https://www.wholesalepartsexpress.com/p ... -dual-air/
$150 shipped.
Here are some images if the joinery that worried me in regards to the flow of coolant. But I figured a more sturdy build was more important.
IMG_20220401_184939.jpg
IMG_20220401_184832.jpg
I just finished installing it thus past weekend. It's not very fun because of the number of various sized hose clamps I had to deal with; 9 IIRC - and half were in tight spaces. Lots of anxiety and stress was exuded in the replacement.
I would had tried the hack fixes of using plastic fitting to rejoin the broken fitting. But something about using an adhesive that could potentially be exposed to coolant system worried me... Plus if that plastic fitting was so easily broken by such light pressure, I worried the other side of the assembly wouldn't be in any better shape.
Thanks for the write up and the pics!!
Re: Where under the hood is the heater inlet pipe?
Posted: Sun May 22, 2022 5:46 pm
by palmerwmd
PS:
Looks like 92408-ZS20A fits both the V8 and V6 models according to this wizard!
However also according to the wizard it does not fit Nissan Xterra even though its supposed to be same powertrain.
https://parts.graydanielsnissanofjackso ... ZS20A.html
Are there any other parts, connectors, flanges or hoses I should order to increase the extreme heat resiliency of my 14 year old pathfinder's cooling system ( rad hoses and radiator and thermostat already done)