Took my Disco in for new Head Gaskets yesterday and asked them to give me a call when the heads were off. I wanted to see what the engine condition looked like inside. Went in today and was amazed, the engine looked absolutely clean. No sludge or carbon anywhere except a minimum amount on the bottom of the exhaust valves - none on the stems. I couldn't believe how clean it was after 85K. I credit the condition to always using Chevron or Shell Premium along with Mobile One in the crankcase. I'll also credit the Seafoam I throw in on every longish highway trip.

Yes, the cost is significant when added to the other work being done but doesn't seem so bad when I remember I'll now be getting several more years use out of the vehicle.