Here’s part of our conversation about valve gunk, its effects on direct-injected engines, and whether there’s cause for concern. Apparently, proper maintenance and following manufacturer ...

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.

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 ...

Add Yahoo as a preferred source to see more of our stories on Google. Fuel injectors don't just deliver fuel. They meter it, shaping the spray so the air-fuel mixture burns in the way the engine wants ...

Gasoline direct injection (DI) engines have been lurking in the shadows of gasoline-burning, internal combustion engine development for decades but are now becoming mainstream. This is all good, as DI ...

Yes. Because the fuel/air mix is directly injected, it does not enter the combustion chamber via the inlet valves and does not clean them. As a result, carbon can accumulate on the inlet valves.

A well-maintained modern car should be capable of covering six-figure mileages without needing any major attention. But it is reasonable to expect some drop off in performance as a car gets older and ...