NS Coolant change

[BLOKE66]

Hi
I know this topic has been spoken about several times but I'm still struggling to get all the old coolant out of the system (3.2 DID).
I've looked at 2 different manuals for the drain plug for the engine block. I still can't seem to find it. I'm looking at the end of the engine oil cooler where the oil filter screws on.....there is a hex head bolt right next to the oil filter but this is for draining the oil out of the cooler...am I looking in the right spot?? Draining the radiator only gets about 5 litres of coolant out.After looking at the picture again now I realise the drain plug is down behind the alternator probably accessible from the top of the motor and not under.....I'll have another look tomorrow.....am I getting close???
Cheers

[Morville]

The non common rail 4M41 (NM NP)had the drain plug near the oil filter but you have it for the NS onwards. Also you can undo the heater hoses under the drivers floor and flush with a hose until the water runs clear. My NW takes about 7 litres of new coolant so quite a bit remains in the front and rear heaters.
Peter

[BLOKE66]

Thanks Morvelle....I thought I may be getting confused with the earlier model.
Cheers

[craka]

What the verdict on where to drain the coolant from on this?
I'm due to change mine shortly.
Any pics would be greatly appreciated.

[BLOKE66]

Hi craka
The drain plug for the block is on the drivers side of the motor (3.2 DID) and it is visible from above and below. The bolt has an elongated head so easy to distinguish from other bolts.It is in an extremely difficult spot....none of my tools where the right shape or size to be able to get at it and undo it.It is a 12mm head. You just need to look through any gaps in the plumbing so you can see the side of the motor...the head of the bolt points down at about 30 degrees to the vertical.
It would be bloody easier if I had taken a photo...I'll give it a go tomorrow.It looks like it screws into cast iron which I'm sure would make it difficult to undo.
So the end result....I gave up on that idea and just did many drain/refills of the system with water.
Disconnected the heater hoses under drivers side floor....clear water came out after several refills.....that was a silly move!!! As it is an insane method of trying to refill the cooling system and not get a heater air lock. A simple air bleed on the heater core would take all the drama out of this exercise. The routing of the heater hoses will always cause air locks.
I'm pissed off as that's what I've got now. So tried a couple of things.....
had the engine idling and removed heater hoses to determine water flow but that only works when the thermostat is open(didn't really want to remove stat but may be necessary)...also tried sucking water from the block into the heater core(this is getting desperate)...seemed to get a bit of flow in the heater but then reverted to air lock.
My next move (if you guys don't come up with a result) is to follow the two heater hoses...hopefully to a higher point than the heater element disconnect both and put a hose in one till water comes out the other.
I am open to any suggestions!!!
Cheers

[BLOKE66]

Well... went out and had another look....the two heater hoses attach at the back of the block...in another difficult position. They would also still be below the heater core I think.
So I think my next move will be to remove the thermostat...run the motor.....remove the return heater hose untill water comes out of the heater core.....reconnect hose...run till motor is hot.
BUT

As far as I know there is no ON/OFF valve in the heater line. Does the coolant run through the heater core all the time?...even when the thermostat is closed?? Does the water pump circulate water through the block and heater core with the stat closed??
I don't really want to remove the thermostat if I don't have to.
The NS Shorty has definitely been the steepest learning curve out of any vehicle I've owned...it's bloody lucky it's a nice car to drive!!

[chutsy33]

Wow, what an effort. think I might just drop the coolant, refill and keep thye run it drop it going for a few drops to flush the system full. I do not have the patience to do what you are. Good luck!!

[gaz1]

I'm not sure if this is the same for SWBs but for the 5 door models there are two coolant pipes under the driver's floor - metal pipe with rubber connecting hoses. It's meant for the rear heater, but is blanked off (shortcircuited?) if there is no rear heater. I've found that disconnecting those hoses when changing the coolant has discharged a lot of the coolant and makes the system empty more completely and quickly - fewer repeat flushes needed. My original NM Exceed didn't have the rear heater, the current NT - VRX does.

[craka]

Hi craka
The drain plug for the block is on the drivers side of the motor (3.2 DID) and it is visible from above and below. The bolt has an elongated head so easy to distinguish from other bolts.It is in an extremely difficult spot....none of my tools where the right shape or size to be able to get at it and undo it.It is a 12mm head. You just need to look through any gaps in the plumbing so you can see the side of the motor...the head of the bolt points down at about 30 degrees to the vertical.
It would be bloody easier if I had taken a photo...I'll give it a go tomorrow.It looks like it screws into cast iron which I'm sure would make it difficult to undo.
So the end result....I gave up on that idea and just did many drain/refills of the system with water.
Disconnected the heater hoses under drivers side floor....clear water came out after several refills.....that was a silly move!!! As it is an insane method of trying to refill the cooling system and not get a heater air lock. A simple air bleed on the heater core would take all the drama out of this exercise. The routing of the heater hoses will always cause air locks.
I'm pissed off as that's what I've got now. So tried a couple of things.....
had the engine idling and removed heater hoses to determine water flow but that only works when the thermostat is open(didn't really want to remove stat but may be necessary)...also tried sucking water from the block into the heater core(this is getting desperate)...seemed to get a bit of flow in the heater but then reverted to air lock.
My next move (if you guys don't come up with a result) is to follow the two heater hoses...hopefully to a higher point than the heater element disconnect both and put a hose in one till water comes out the other.
I am open to any suggestions!!!
Cheers

Thanks for the info on this. Bloody sorry it's given you a hard time, I'm not looking forward to doing it when I get to it.

[BLOKE66]

Sorry guys forgot to finalise this one.
So I finally got rid of the air lock in the heater core.
I parked the car facing up my steep driveway.....removed the thermostat housing and took the stat out. Then I removed the top radiator hose from the engine housing on the other side of the motor.Put the hose (i've got good water) into the thermostat hole and filled with water till it came out the other side of the motor....which only left the radiator to fill.
I put the gasket off the stat back in the housing and bolted it back onto the motor(no stat installed).
Reinstalled top radiator hose on the other side of the motor.
Now I already knew that the radiator would take just over 4 litres which is pretty much the amount of coolant needed.
So I filled the radiator with Coolant Concentrate....put the radiator cap back on and took it for a drive straight away so as not to have the concentrate sitting for too long. I took some pre-mix coolant with me.
Well it wasn't too long before the heater started to work. Drove the car for about 20 mins and then let it cool down with the radiator cap off....had a few more bubbles come out and needed topping up a dash.
Put the empty coolant bottle under the radiator drain hose and drained out around 4 1/2 litres. It was all well mixed with the water now after driving the car without the thermostat in.
Removed the thermostat housing and lost no coolant as the level was just below that point.
Replaced the thermostat/gasket and housing.....all is good!!
It has been a pain in the butt but it's good to end on a positive note.
What has come out of this exercise is finding the Viscous fan is not working as good as it should which would have been part of the reason the car was getting a bit warm at times.... which is why I decided to replace the coolant as it would have been quite old.
Looks like another story is coming....I've got my bottle of Toyota Silicone Oil.
Cheers

[rykiel575]

Viscous fan was also what was causing my old NP to overheat. Ended up replacing it as it wasn't too expensive with aftermarket

[BLOKE66]

The viscous fan is a cheap and easy repair but I'm afraid some early posts on repairing them had a few omissions that can make the repair a bit hit and miss. I'll expand more on that when I'm finished re-oiling mine
Cheers

[BLOKE66]

The viscous fan is a cheap and easy repair but I'm afraid some early posts on repairing them had an omission and a minor error that can make the repair a bit hit and miss. I'll expand more on that when I'm finished re-oiling mine
Cheers