Bought car used with 90,000 miles. Now has 109,000 miles. Buring oil fast. Mechanic opened up motor and said it had a lot of sludge. Said it needs to be replaced. It has been running great except for using oil. Question, can it be flushed or is the motor bad? How do you know the sludge has ruined the motor?

 

when you are leaking oil into combustion chamber your engine will start detonating pretty quick...either blowing your ringlaids, melting down the head, or plain out cracking your cylinder wall. The problem could originate from either your head leaking oil through valves, or worse cracked rings sucking oil up from the crankcase into the chamber...In either case the sludge is probably the result of oil leak. check compression, or if the head is already off, inspect it(head) for leaking valves, condition of the valvetrain, and then check inside of your cylinder walls for any surface scratches(cracked rings will scratch the inner wall of your comb.chamber) good luck