My 2006 Cobalt SS/TC has about 75K miles on. It has a miss in the engine that is happening on light acceleration. Its kind of minor but at the same time it’s not really drivable. There are no codes. At times (not often) it sounds like the valves are knocking and that’s not a good sound at all. Criswell Chevrolet Service has replaced the coil in #2 and new spark plugs. No luck. They explained it’s not electrical which is horrible news.

I told them to go further. Now the head is off and looks fine to them. they will have it sent to a shop for magnaflux. Service man is saying likely next step is to replace valve springs.

Any comments appreciated.
Jack