hi just some advise if someone out there can help i got up for work the other morning to go start the car which is an Audi RS4 B7 2006 and it started with a misfire so switched it off and left it a couple of minutes then tried again but this time its started knocking so turned it off straight away so got a mate with his vag com to check for any codes and there was nothing so then tried a compression test and 8 out of 7 were about 160 and the other one there was nothing so decided to take rocker cover off to look for any damage and the one cylinder with no compression the rocker arm was loose it was that loose i was able to take it out by hand so could this be a stuck valve or something more serious i also did a boroscope down the plug hole and there's is no damage what i can see to the piston thanks for reading
