carbon deposits Archives - Tomorrows Technician
Carbon Deposit Q&A

Follow along to learn more about carbon deposits.

Carbon Deposits In Direct Injection Engines

The primary cause of these problems is that fuel and added detergents are not hitting the back of the intake valves.

Carbon Deposits and Direct Injection Engines

The primary cause of these problems is that fuel and added detergents are not hitting the back of the intake valves.

Oil and Carbon Deposits

Here’s how oil can influence carbon deposits.

VIDEO: Solving The Carbon Deposit Conundrum

Carbon deposits can be formed by varying cylinder temperatures. This video is sponsored by Rislone.

The Carbon Deposit Conundrum

During some combustion events, a droplet of fuel or oil is transformed into a substance that can become a carbon deposit. This typically happens when there are conditions that are outside of the normal operating conditions.

Curing Carbon Deposits On Direct Injection Engines

Direct injection improves fuel economy by injecting the correct amount of fuel for the conditions in the combustion chamber. But, it is not a perfect science: Carbon deposits can form on the intake valves, piston and other surfaces in the combustion chamber.

VIDEO: Carbon Deposits On Direct Injection Engines

Jon Nelson explains why carbon deposits happen and how to diagnose misfires and clean intake valves.

Direct Injection And Carbon Deposits

In 1985, Saab began using the new Bosch LH fuel injection system, and Volvo and other carmakers followed suit. The system worked such that incoming air passed through an airflow meter that sent a signal to the engine ECU telling it how much air was going into the engine. The coolant temp sensor then told the ECU how cold or warm the ­engine was, and it opened and closed the injectors when needed.

Solving Carbon Deposits In Direct Fuel Injection Engines

When the early direct-injection engines hit the three-year or 30,000-mile mark, some developed driveablity problems due to carbon buildup on the necks of the intake valves.