Oil & Water Coming Together: Possible Causes?

[slickshoot]

I had a problem at the weekend with the temperature rising in my mini. After shutting the engine off & inspecting under the bonnet I could see a large amount of water had mixed with oil & been blown out of a breather into a catch tank. On removing the head however the head gasket appears to be intact & undamaged.

I'm just looking for a few suggestions about what else to investigate as a likely cause, cracked head or block perhaps?

Any advice/suggestions appreciated.

[guru_1071]

id say the gasket

its rare that either a block or a head will crack in such a way that water will be able to get into the oil.

carefull inspection is needed i think!

[Skyedriver]

Is there a close link between oil and water at the oil pump, seem to recall Peter V bringing this up some time ago. A hole in the housing or something and a gasket alignment...?
Been driving the orange shelf for a few days this week so it could just be brain damage.
(ps put 500 miles on it since the recommision and the clutch isn't slipping any more) - sorry for the hi jack

[Cooperman]

I had the most unusual problem with a 1275 engine a few years ago. I was getting a lot of oil in the water and suspected a head gasket. Changed it and the oil getting in the water continued. Several people said 'cracked head'or 'cracked block', but I have never seen a crack in head or block allowing oil into the water. I stripped it all down and gave it all a thorough inspection, but found nothing and re-assembled it again. Still got oil into the water. Then I was talking to a friend who knew someone else who had the same problem and had stripped his down 3 times until he finally found the problem.
It turned out that when a Mini is changed from a 3 or 4-bolt oil pump to a 2-bolt later slot-drive type, one of the tapped holes for the now unused oil pump bolts can break through into the water jacket. That is not an issue when 4 bolts are used. At that point the oil pump gasket is only about 2 mm wide and the initial high oil pressure coming up the unused empty hole can break through into the water jacket. I just blanked off the redundant holes with home-made studs fitted in with Loctite, re-fitted the pump and it's been fine.
It was a very strange problem and a real head-scratcher at the time.

[Skyedriver]

Y'see I do remember things!
And people call me an ol'bu66er...
Now where did I put me glasses?

[camelotr]

If You use a water cooler oil cooler (MG Metro type for example), it can corrode through and mix oil and water.