I was cruising along about 5 miles away from home and I start to hear a disgusting knock. At first thought I say I must have cleaned out a bearing but I don't know. I changed the oil and saw no glitter or shavings (check one). Pulled the vc's to see if it was possibly a bent push rod or roller rocker out of wack....nope (check two). Listened for the noise with a scope all around the motor and the sound is very hard to pin point. If I put my ear to the intake I hear it the loudest and to the back of the motor around the bell housing I hear it the loudest. The last check I did was pull each plug wire while the car was running to see if I could get the knock to change a note. NO MAS! What could my knock be?