SurrealOne can you take a video of the noise so we can hear if its a knock or tick because they are very different. Tick is usually lifters which all...
Not to sound mean or stupid but what exactly is the problem? I didn't fully understand it the way you explained it. Also I think you mean oil change...
Minneapolis area - 1997 K2500 regular cab long bed, pushes plow in the winter, carries camper in the summer - 2004 4x4 Suburban 2500 8.1, pulls 30' Airstream trailer