A common problem on late-model engines with Gasoline Direct Injection is:

Gasoline Direct Injection (GDI) engines are known for their efficiency and performance, but one significant issue they commonly encounter is carbon buildup on the intake valves. In traditional port fuel injection systems, the fuel flows through the intake manifold and helps wash the intake valves, keeping them clean of carbon deposits. However, in GDI systems, fuel is injected directly into the combustion chamber, which means it bypasses the intake valves entirely. This lack of fuel flowing over the valves allows carbon deposits to accumulate over time due to oil vapor and other combustion byproducts.

The carbon buildup can lead to issues such as decreased engine performance, rough idling, and even misfires if the buildup becomes significant enough. Additionally, these deposits can disrupt the airflow in the engine, affecting the engine's efficiency and emissions. Therefore, recognizing this carbon buildup as a prevalent concern in GDI engines is crucial for maintenance and troubleshooting.

The other issues in the choices may occur in different types of engines or under specific conditions, but carbon buildup on intake valves is a well-documented and widespread problem specifically associated with late-model GDI engines.