VX Over Heating!! Water Flow or Water pump diagram/help

[phillmac]

I had a hell of a time trying to bleed air out of kids new VX. Will try filling top hose next as bleed screw wont let all air out and it seems to be in top hose. Only got about 7ltrs of coolant mix in but it seems these motors don't fully drain unless you screw out sensor plugs or something from block.
Should have read the instructions before I did job instead of after.

 

[billythakid]

Bleed them with the front of car uphill is the best way . I always put mine uphill , heater on , bleed it with a bottle in the radiator idling , crack the bleed screw till coolant flows out the close it for a few min , crack it open till coolant flows , close it , remove the bottle. , put rad cap on , go for quik lap of the block with heater still on , nose up driveway in park idling crack bleed screw till coolant sprays out ( usually hits passenger exhaust) shut it off and top it up next morning when cold .
Never had an issue with air in system!

 

[lout]

just to add a warning
never remove a radiator cap from a hot motor
when you say your car is overheating what symptoms do you have
gauge on hot?
or engine seems excessively hot?
or overflowing coolant recovery bottle?
or blowing steam?

 

[Immortality]

Seems like a lot of effort to bleed a cooling system and a waste of time at that.

I have tried the bottle in the radiator technique once and found it works no better than doing it the standard way.

Car on level ground, top up the radiator as much as possible, start car with heater on full hot, bleed screw open. Keep topping up the coolant as required. When the engine reaches operating temp the coolant level will drop a fair bit as the thermostat opens and allows full flow through the radiator. When you start to get coolant coming out of the bleed screw close it. At some point the coolant will start to come back out of the radiator cap. Put a new radiator cap on. Top up the expansion tank as required. Drive car.

If the coolant recovery system is working properly it will purge out any remaining air. Part of this system is a well functioning (correct pressure) radiator cap. As the coolant system heats up and pressurises some excess coolant will be let out of the coolant system into the expansion tank. When you have recently had the coolant system open any remaining air will collect at the high points, the radiator cap been one. So as the pressure builds that air will be forced into the expansion tank, when the system cools, coolant will be sucked back into the coolant system from the expansion tank. This is the reason why the expansion tank should never be filled past the max fill line on the tank as it requires room to take the extra coolant from the system when the engine heats up.

So, once most of the air has been bled out of the system, just make sure the expansion tank is topped up, if you're anal, after the first few drives of the car just crack the bleed screw to ensure no air is there but you shouldn't have to keep opening the radiator cap. Just monitor the expansion tank

This is the reason why I actually like the coolant system on the s1 VN. The expansion tank was part of the coolant system (been the highest point) and it had special bleed lines which ensured any air was purged from the engine as the coolant was added. All late model cars now run similar systems. I DO NOT like the VT - VY V6 expansion tank configuration with it been lower than the radiator. Silly design :bang:

 

[wortus]

It's not an expansion tank on a VT-VY it's an overflow bottle. An expansion tank holds the cooling system pressure an overflow doesn't. Cooling system won't self purge all of the air on a VT to VY simple reason is the top of the engine is higher than the top of the radiator. it needs to be bled with a "head" of coolant and the simplest way to do that is to put something that seals into the top of the radiator so it is the highest point on the system.

The early VN systems with the surge tank are good as they self bleed but the small steel pipes from the top of the inlet manifold to the top of the surge tank block up easily which then stops self bleeding.

 

[phillmac]

The VX seems to have settled it's self OK, just 1 slight top up and top hose is solid with coolant now. The up hill didn't seem to help but didn't do the full fill on the steep driveway. The w/s manual did state the fill top hose and quickly fit which would prob help.

 

[wortus]

yeah filling it through the top hose and quickly fitting it is in the manual as an alternative to not having the proper tool which can be made up out of a bit of old radiator hose or a plastic bottle to seal into the top of the radiator to give a head of coolant.

 

[Immortality]

I still say you're over thinking it.

Once the majority of the air is purged during the initial fill/purge using an open radiator and bleed screw the radiator cap will take care of the rest expelling it to the over flow tank At the end of the day, the thermostat/housing and top radiator hose is the highest point so no air will be in the engine where it can possibly do damage.

Sadly, it seems I can't find the CPC radiator caps any more where I am