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 ...

We may receive a commission on purchases made from links. Dirty fuel injectors can cause many problems, from minor annoyances like a rough idle or lower gas mileage, to more immediate and pressing ...

Carbon buildup can cause a loss of engine performance, usually happening on high-mile engines that have plenty of sticky deposits after decades of running. A popular trick dating back to the hot ...

Polycyclic aromatic hydrocarbons such as anthracene and pyrene in gasolines are believed to be one of the causes of deposits in internal combustion engines. One source of these compounds is heavy ...