Removing unnecessary coolant hoses from KA24DE, which must be kept?

[Matej]

Currently I am in the process of removing and/or plugging whatever I can from the vicinity of the intake manifold. Since my car does not have a heater core installed, I want to remove all the extra coolant hoses as well. However, there a few I am not sure about.

Here I marked the ones I do not know if I can plug. My marks are the yellow ones, please ignore any others. Sorry, the pictures are not mine.
http://www.matejblahut.com/gallery/d/243-1/coolantlines1.jpg
http://www.matejblahut.com/gallery/d/249-1/coolantlines2.jpg

#1
Normally this hose would go to the heater core, but since I do not have the heater core, I have been running it looped into the hose labeled #4. Is it alright to just plug it off where it comes out of the block, or would it be necessary to loop into something else if I remove hose #4?

#2
This hose runs from where the upper radiator hose enters the top of the intake manifold straight to the back of the water neck. What does it do? It seems that this hose is either very pointless, or very important. Can I remove it and plug both ends, or is it necessary to keep?

#3
Alright to plug, or should something be looped into it?

#4
Please see #1. :)


Thank you for any information.

[projectRDM]

You have to keep #2. That flows water behind the thermostat for bypass before it opens.

Take #3 and run it straight to #1. That block fitting can be turned around to face the front of the engine, making it simple.

Delete everything else on the intake manifold.

[Matej]

Thank you, that's exactly what I needed to know. Wish Zilvia still had the reputation system so I could give you some.

[enti7y]

i don't mean to bring a post back from the dead, but i recently talked to someone who was supposedly good with Nissans and he said you can block #1 and #3. and in theory if one wasn't to run a thermostat #2 could be removed too.. leaving only the radiator inlet, and outlet.. the engine should still have sufficient cooling.. i will however run a thermostat so i will be keeping #2.. but as i said, #1, and #3 are pretty pointless without a heater core. and if you plug both of those you can take out the heater core routing (#4) in the intake manifold. doing all of that should free up a bunch of space in the engine bay.

18377

[Matej]

Thank you for the input.
However, I have been told on KA-T.org that the car would overheat if I block all of them off.
I am not sure if they meant even if I only plugged off #1 and #3, which would be nice to get rid off.
I do plan to keep my thermostat and #2 along with it.

[Matej]

The only reason I would see #1 being looped into #3 as necessary, instead of plugging them, is if the coolant passage in the engine block is not wide enough. That way the waterpump would be pumping more coolant than can flow through the block. Which might cause leaks and/or overheating. Thus #1 being necessary for relieving the excess coolant being pumped.

However, that is just my theory. I am not sure if the coolant passage actually is too narrow or not.
Can anyone confirm whether #1 really is necessary?

projectRDM? You are the expert when it comes to all things KA. :)

[98s14inaz]

Heater core is still good to have in case of an emergency like if your electric fans stop working. I'd advice against removing it but hey, it's your car. I'm also out here in AZ so the heat affects our cars a lot quicker.

[sidedrifts13]

my #2 hose is leaking what is the best way to replace it but without taking off the manifold?

[ihatesmog]

To remove it, it requires a bunch of cuts on your hands and some elbow grease. You can do it. I pulled out the purge volume solenoid thing out of there and had to remove one side of the hose you're referring to. Just takes patience.

OP - not sure if you've already done this but you don't need the coolant lines that flow to the throttle body.