November 26th, 2014

Can a diesel engine oil overfilling lead to any damage?

Fully filling your oil isn't always the finest oil level

By overfilling your Sprinter Van's diesel oil , you risk flashing warning lights, engine shutdown, and poor engine performance.

Some mechanics insist on filling the engine to the exact amount of oil specified in the owner's manual. With some models and in some situations, this common practice can lead to a number of issues. Especially in climates with high temperatures, oil can expand and trigger the sensor of your Mercedes-Benz Sprinter Van accurately informing the operator that there is too much oil in the engine. On occasion, drivers who are experienced with this issue understand that the diesel Sprinter Vans' warning lights stop flashing after 10-15 minutes of running; they may take the risk and choose to ignore the light.

The problem with that behavior is that even though the sensor is not flashing anymore, the initial 10-15 minutes of usage can lead to serious issues on some parts of the engine.

Overfilling oil is a bigger problem with diesel engines than regular gasoline engines, as the oil can mix with the diesel going into the combustion chamber. When this happens, the filter will wear out at an accelerated rate. Unnatural black or grey smoke might also start coming out of the exhaust because of wear on the filter.

However, there is a much more serious issue that is not as easy to solve as merely changing the filter.

See also: How to prepare your Mercedes-Benz Sprinter Van for winter

Diesel engine runaway – the biggest risk of oil overfill

Diesel burning engines have a specific issue that does not happen to gas-based cars, because the chemical composition of the fuel is similar to the lubricant inside. This means that any oil vapour being forced into the combustion chamber, which could be due to overfilling or even the slightest mechanical unbalance, may lead to the mixing of oil and fuel will create a feedback loop in your engine.

Overfilling diesel engine oil

Experiencing a feedback loop means that you will not be able to stop your engine until it burns out all of the fuel. Burning all the fuel and oil together will is destroy the engine. Feedback loops most commonly occur in turbocharged engines. When a diesel engine runaway occurs, the only hope you have to stop it is to plug the air-intake!

Overfilling oil in your Mercedes-Benz Sprinter Van may ultimately lead to your engine being totalled. Not everyone is a mechanic, and not every mechanic fully understands Sprinter Vans, be sure to pick the right mechanic to ensure your safety and the quality of your ride.

In the following video you can see how to change an oil filter on a Mercedes Benz Sprinter Van (don't forget to Subscribe to Sprinter Rentals' Youtube channel):