Expansion tank split oil leak related?

[Shanos]

Hi my wife's mini had a warning light come on a few days ago, she stopped immediately and had the AA out, they pressure tested the expansion tank and it was hissing/p1ssing water from the central joint, I understand this is a common failure and have ordered an ally header tank to replace the plastic piece of poo.
He also checked the oil and it was very low, I have hunted it down to what I believe is a leaking crank sensor seal (see my other post about this), my question is, are the two related? Would the low oil have caused the engine to get hot and boil up the water? Or is it likely to be something different and just happen to have come at same time?
What would you advise I check re the water, or is it just likely to be the split tank that has caused the overheating.
Normally I love chicken and I love eggs, but when it's a case of chicken or egg problems I am not so keen
Thanks in advance for any info you can provide.
Shanos

[Shanos]

Just a thought has Evans power cool/race cool 180 been tried in the mini? Saw it on wheeler dealers a little while ago and seems great.
From there website
Protect your investment!
A waterless engine coolant specially formulated for performance vehicles. Race Cool 180º protects engine cooling systems from -40ºC to 180ºC. The unique properties prevent many of the problems associated with waterbased coolants such as Premature Detonation and Overheating.

Benefits

No Water - No Overheating
Power Cool 180° has a boiling point of 180°C and will not boilover.

No Water - No Corrosion
Water contains oxygen, oxygen allows corrosion. Race Cool 180 eliminates corrosion.

No Water - No Pressure
Power Cool 180° allows your cooling system to run at a lower pressure, reducing the strain on engine components.

No Water - No Liner Pitting
Power Cool 180° generates significantly less pitting when compared with all water based coolants.

No Water - More BHP
Power Cool 180° eliminates premature detonation associated with overheating.

* Please note: this is has been known as Race Cool 180°

Note: comes in a 5, 10 and 25 litres bottles

Ideas and thoughts please

Shanos

[mab01uk]

Expansion tank split and oil leak are very unlikely to be related.
The split tank is likely the cause of overheating as the leaking away of any cooling system pressure causes the coolant to boil at a lower temperature. That is why the system is pressurised in the first place.

[Shanos]

cheers Mab new tank arrives tomorrow hopefully.
will advise how I get on.

tank just arrived and is now on the car, it looks the nutz need to get some coolant and refill the system

[mab01uk]

After refilling you may need to bleed the cooling system of air, if it got too low or into the heater matrix, details on how here:
Solving MINI Cooling Problems.......... - Forums

[Shanos]

just printed off the guide and will get on to it tomorrow, my friend has borrowed my halfrauds trade card so i will need to grab it back from him (don't fancy paying their full prices )
just wondered on the guide it advises service mode before draining down, can it be done without this?