ok so my 3.0 is a low mileage motor from japan that was swapped into my truck. when i baught it i was told that it had about 35,000 miles on it. now it probably has 50,000. This morning right as i pulled into work it started knocking really really bad! its sounds like it is coming from the upper part of the engine. like one of the valves or something. i checked the oil and it was full... so for shits and giggles i drained a little oil out and dumped in a quart of lucas thick shit... i hope it helps when i get in it to go home tonight. goes to show you how shitty those 3.0 motors really are!