Modern engines are cleaner and more efficient than the ones you grew up with, yet many drivers are discovering a new headache ...

The other day I dropped my car off at a European specialist shop, and while I was there, a technician was working in the engine bay of a Mk7 Golf R, cleaning out carbon deposits off the intake valves.

If oversize valves are installed and the combustion chamber left stock in size, the chamber walls will shroud the valves. By using a head gasket to transfer the cylinder pattern to the blued surface ...