Hi guys, Looking for some help on a 2008 STS light engine knock in a 4.6 Norstar engine. It seems the noise happens when I accelerate from a dead stop or when accelerating when driving the car. The noise lessons or disappears when you get above 4000 RPM. It could be that the engine noise is just drowning it out but I can’t seem to hear it anymore. Also the noise is louder upon first starting the car after it sits overnight. After about 5 minutes though it seems the noise does lesson and stays consistent throughout the day even if I shut the car off and let it sit for some hours. But I can still hear it. It doesn’t happen at idle and the car runs well. It’s only when I start to rev the motor you can here the noise. I don’t believe that it’s a crank shaft bearing or a main bearing because it would happen at idle as well and certainly would get worse as the car got hot and not when it was cold. But I am not sure and would like to hear your expert opinion on the situation as I’m not real familiar with the northstar engine or Cadillac for that matter. This is my first purchase and try with Cadillac so I hope I didn’t just make a mistake.