oil in the coolant and vise versa.. :(

[thstone]

My most recent engine failure went like this...

Losing coolant.
Continued to drive the car.
Replaced coolant tank. Still losing coolant.
Continued to drive the car.
Tightened all coolant connections. Still losing coolant.
Continued to drive the car.
Coolant system pressure test fail. Still losing coolant.
Continued to drive the car.
Compression/leakdown test. Leakdown test fail.
Continued to drive the car.
Engine stumbles once and low oil pressure light on intermittently.
Engine back to running fine. Continued to drive car. Low oil pressure light on solid.
Continued to drive car. Engine stopped running. Won't start or run.
Installed replacement engine.

I hope that your situation works out better than mine did.