we had a ford windstar with 152k miles on it come in the shop cause the oil light was on and it was chattering bad even though it was full of oil. pulled the front valve cover off and their was a perfect mold of sludge under it that made it look like the cover was still on.... :shock: so i pulled off both covers and scraped out and cleaned them and the heads and placed them back on the motor. then ran the motor to temp and drained the oil and filled the whole motor to the top of the valve covers with kerosene and let it sits for a few days. it broke down the sludge in the motor and we drained and screened it and it was some nasty stuff...
then i put a cheap filter and oil in it and ran it for about ten minutes and re drained it and put better oil and filter in it :wink: now the guys has over 200k on it and comes every 3000 miles for oil changes like clock work..... lol