I have coolant in my oil.. after overheating.. sounds like classic head gasket failure right?

I took the head off and didn't find any signs the gasket was bad.. (just like in the Mod Mini head gasket videos) I took the head to the machine shop and they inspected it and said it was in great condition..
I'm wondering if there is anything else that could cause coolant in the oil? I have only heard of this being caused by the head gasket... or oil cooler.. The car still ran great.. only symptom was to coolant in the oil...

1 week before it overheated.. To fix an oil leak. I was changing the oil pressure sensor and oil cooer rings... when I got the oil cooler off it looked like it had peanut butter inside it.. I called the local Mini Mech and he said it needed to be replaced. So I put on a new oil cooler.

The next weekend I was trying to flush the coolant system by running distilled through the car while letting it idle a while.. then dumping it. letting it cool, and repeating.. on the 3rd time I walked away for a minute and the hose popped off (because it didn't put the clamp back on.. lesson learned) and it overheated.... I shut it off and let it cool.. then refilled and dumped the coolant again.. then I used a very small shop vac like has been discussed in this forum to get all the coolant/water out before refilling with the expensive coolant. The last thing I did was change the oil.. at that time the oil did not have any coolant in it..

3 days later I check the oil and see the white goo on the dip stick and inside oil fill cap. I changed the oil again in hope I somehow had moisture in the engine.. But after a day or two the coolant was in the oil again.

My question is..
With the oil cooler already being new.. is there any other source of the coolant in the oil other than the head/ head gasket? could I of damaged anything by using the shop vac to suck out remaining coolant? While the head is off is there anything else to check? The machine shop mentioned a freeze plug issue but I think that is Gen 2 Mini's

Any help would be greatly appreciated... I plan on putting the car back together this weekend..

P.S. While its apart upgrades been done:
15% pulley
Mild street cam
380 blue fuel injectors
new coolant reservoir
valve job
super charger oil change

 

The most recent overheat may be the issue now after you changed the oil cooler (you are talking the one at the filter housing correct?).

 

Did the cylinder head inspection include a pressure test? See photo showing where my cylinder head cracked.

 

Yes. The one attached to the oil filter housing... Hopefully it didn't fail that soon...

 

I don't thing they pressure tested it... It was cleaned up real good, inspected and valve job done... I just went and looked at it where you circled.. Its real clean now and I don't see any sign of a crack..

 

After putting it back together I'm still getting coolant in the oil.. Moving this conversation to another thread... any help diagnosing this would be greatly appreciated as I don't know what to do at this point.

https://www.northamericanmotoring.co...ml#post4410417