! That can't be good. If it looks clean inside just like a new one, that suggests oil was bypassing it. There are only two possibilities I can think of. One would be a protective cover that didn't get removed when it was installed, and that isn't as silly as it sounds. Some filters come with a cellophane sheet over the threaded end but I would suspect that would have been seen when the filter was removed.
All filters have a bypass valve to let oil pass around it to prevent oil starvation if the filter becomes plugged. Some engines also have a bypass valve built into the oil filter housing. If that valve sticks open oil would not go through the filter but I find it hard to believe the filter would remain dry for thousands of miles.
Sunday, March 6th, 2011 AT 12:14 AM