Air Drain Plug For Coolant Bleed

[Marko R1]

hi guys,

i have followed procedure to replace my coolant in my gtr & have removed the 'air drain plug' which sits on the front of the engine, just under the injector boom.

when i release this bolt though there is no visible sign of coolant bleeding through this hole, i even removed the bolt & still no sign of air or coolant bleeding through...could it be blocked in some way?

i let the engine get to full temp on idle & followed my workshop manual.

regards

[JD_R33]

Thermostat not opening maybe?

With the engine cold you could remove the radiator cap and the bleed bolt, then try blowing back through it with a bit of old vacuum hose to see if it's really blocked.

[mad082]

had you already dropped the rest of the coolant out?

[mad082]

i just read my r32 workshop manual and it leads me to believe that you shouldn't actually see any coolant through the air bleed screw hole. the way it says to do it is to drop the coolant, then fill it back up leaving this bolt undone. then once the radiator is full you put the bolt back in and put the cap on then run the car until it comes up to temp to open the thermostat. then allow the car to cool and remove the radiator cap to check the level of the coolant. if it is low then remove the bolt and top the coolant up then put the bolt back in, replace the cap and run it again up to temp, let it cool and then check the level again. this leads me to believe that if you are following this process you won't actualyl get any coolant coming out of this hole or any obvious signs of air coming out of it. i know that on my 33 gts-t if you removed the air bleed screw when the car was cool nothing would come out. if the car was running when you did it you would get a few bubbles come out and it would spit out a bit of coolant.

[Marko R1]

has a new thermostat.

i do remember on my old gtr that coolant would bleed thru the air drain plug.

1 of my mates suggested it is blocked so poke it with a piece of wire & should be ok

[mad082]

yeah it is worth a try

[Duncan]

did you end up sorting this? it should have coolant come out once it is up to temp and pressure when it is bled correctly.

if a normal bleed is not working, make sure the front of the car is raised a little (on stands/jack if necessary), take soft drink bottle with the botton cut off and wrap the kneck in electrical or similar tape so it is a snug fit in the radiator neck. fill the bottle with coolant (ie the level in the bottle is the highest point coolant can get to.

if everything is working OK coolant should come pouring out the bleeder straight away. If not something is blocked

[Marko R1]

did you end up sorting this? it should have coolant come out once it is up to temp and pressure when it is bled correctly.

if a normal bleed is not working, make sure the front of the car is raised a little (on stands/jack if necessary), take soft drink bottle with the botton cut off and wrap the kneck in electrical or similar tape so it is a snug fit in the radiator neck. fill the bottle with coolant (ie the level in the bottle is the highest point coolant can get to.

if everything is working OK coolant should come pouring out the bleeder straight away. If not something is blocked

i havent looked at it as yet been busy with house reno's, it is for sure blocked duncan and thanks for the tip...i use a funnel which is a snug fit on my radiator & does work very well BUT i like things to work the way they are designed to i.e. bleed valve

do you know ben taylor by any chance? if u prefer pm me

[Duncan]

interesting question....sounds like a bloke that came to our last track day (idontownaskyline).....pm sent

[Marko R1]

haha thats him!