N/A coolant bypass

Nissan 300ZX technical discussion forum: Maintenance, performance, installations, modifications, how-to's and troubleshooting.
livinglegend2100
Posts: 1375
Joined: Fri Feb 08, 2008 4:11 pm

Post

I removed the EGR, and deleted all of the coolant lines for the intake plenum. But i am left with this rats nest behind the engine. The smaller hardlines i know went to the plenum lines, but The two large coolant pipes im not sure what to do with. Do those two large coolant pipes run to the heater core? the car the motor is going into doesnt have a heater core so if thats the case, is there a nice "tidy" way to tie those two large coolant pipes together?

Image


nissanfreak12
Posts: 1709
Joined: Sun Jan 23, 2011 4:07 pm
Car: 92 300zx 2+2 TT
Location: Denver, CO

Post

Yes, they run to the heater core. You can always cap them off. The one on the driver side, you can just make a plate and block it at the connector and remove the whole upper section. The passenger side, either leave alone with a cap or cut it down and cap it off. But if you cut it and decide later you want a heater again, you could be SOL.

livinglegend2100
Posts: 1375
Joined: Fri Feb 08, 2008 4:11 pm

Post

i wont be putting a heater core back in, so thats not a problem. but will i be starving anything of coolant by just capping both of those lines off? i feel like it would be a safer move to keep the coolant flow between them.

nissanfreak12
Posts: 1709
Joined: Sun Jan 23, 2011 4:07 pm
Car: 92 300zx 2+2 TT
Location: Denver, CO

Post

You can, but you will not be starving anything on an NA. The other thing you can do is cut the passenger side down and loop a hose from the driver side to passenger side.

livinglegend2100
Posts: 1375
Joined: Fri Feb 08, 2008 4:11 pm

Post

thats kinda what i was thinking, but if theres no need for the coolant to be returned back into the passenger side tube, then ill just block them both off. one less leak to worry about

JVZ32
Posts: 4
Joined: Sun Apr 22, 2012 11:24 pm
Car: 1996 300zx Z32 N/A
Location: Southwest Texas

Post

Hey man im new to this forum...sorry for replying out of nowhere. i wanted to ask u if u have had any problems with your Z since the coolant bypass? To be specific i mean like on cold start-up's or hot, has that affected your Z in any way?

User avatar
PAintballa45
Posts: 126
Joined: Fri Aug 14, 2009 1:37 pm
Car: 1991 300zx n/a (TT in progress : D) slicktop
Location: Boston MA

Post

JVZ32 wrote:Hey man im new to this forum...sorry for replying out of nowhere. i wanted to ask u if u have had any problems with your Z since the coolant bypass? To be specific i mean like on cold start-up's or hot, has that affected your Z in any way?
i did my bypass in 2010, looped the lines in the back of the plenum before the heater core with no ill effects, havent touched it since besides making sure everything is nice and snug whenever i pull my upper plenum

JVZ32
Posts: 4
Joined: Sun Apr 22, 2012 11:24 pm
Car: 1996 300zx Z32 N/A
Location: Southwest Texas

Post

So no hesitation whatsoever, because doesn't it matter if u live in a cold place?

User avatar
PAintballa45
Posts: 126
Joined: Fri Aug 14, 2009 1:37 pm
Car: 1991 300zx n/a (TT in progress : D) slicktop
Location: Boston MA

Post

nope no difference, im in new england so we get a little of everything

JVZ32
Posts: 4
Joined: Sun Apr 22, 2012 11:24 pm
Car: 1996 300zx Z32 N/A
Location: Southwest Texas

Post

Ok...i went ahead and deleted the water lines completeley. Damn, the little hoses under the plenum were clogged really bad. No wonder why my intake plenum was always hotter than it should be. :frown: I have also deleted my heater and shaved down the hardline pipes exiting the firewall since I live in Southwest Texas(pretty hot throughout the year) I won't need it whatsoever. I'm not sure how to post pictures since I'll always be replying through my phone. Sorry for this... I would like to add pictures so I'll figure it out soon.


Return to “300ZX (Z32) Technical”