Years ago I broke off porcelain from the spark plug which fell into the engine. Uses oil ever since. Now it is running roughly, at 72000 miles.
WHen does a PCV valve go bad? How can you tell? on 2002 Mazda B2300
have a compression test done on that cylinder. have them do a wet and dry to see if there is ring damage. the damage may be surfacing now from that action.