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.

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

Q: I have a 2009 VW with gasoline direct inject and a 2.0-liter turbo engine. It recently needed the intake valves cleaned (a very costly job) after just 54,000 miles. I understand many manufacturers ...

Gasoline direct injection, or GDI, is one of the most crucial bits of technology in the modern internal combustion engine. In engines equipped with GDI, highly pressurized gasoline is sprayed directly ...

Valve gunk is nasty stuff that comes from the toxic vapor of steam, oil, gasoline and hydrocarbons circulating around the inside of your engine. A normal process of combustion in any gas powerplant, ...