 Help diagnose! Engine tap... and more.......
Hey guys... this is my 1st post and I hope you all can help shed a little light. Im a car guy, but learning how to work on these cars so forgive me if I seem dumb. My wife has an 05' "S" 6sp,with 68,000 miles. All of a sudden it starts this tap/knck in what I would bet was the top of the engine. I pulled the cover and seen nothing wrong, but when I did internet research I found out about some having the tensioner issues so I ordered 1. It should be here tomorrow. So today I put the V/C back on and the other small things and started it and noticed the header/manifold started glowing red after maybe 30seconds! What does this mean? Its running lean? supercharger is bad? No issue other than the knock, check engine lights etc any help would be appreciated. | 
