Turbocharger — General Description (Mercedes-Benz Sprinter 903)

In cases where the engine stops developing full power, for example, the maximum speed is not reached, the problem may be related to the turbocharger. If it is faulty, it should be replaced as it cannot be repaired using normal tools. To ensure reliable operation of the turbocharger and maintain the required boost pressure, the entire system, from the air filter to the exhaust pipe, must be sealed. If you suspect a leak, check the following connections:

• the air pipe between the turbocharger and the air filter, as well as the pipe between the air filter and the high-pressure fuel pump. The pipes may be leaky or loose;
• air can enter the engine between the air filter and the cylinder head;
• the air filter mounting flange may be leaky;
• there may also be a leak between the exhaust manifold and the cylinder head or between the manifold and the turbocharger.

A special device is used to check the boost pressure, so this work should be done at a service station. If the pressure is too high and the supply to the boost pressure regulator is not clogged, most likely the turbocharger needs to be replaced.

The cause of the malfunction may also be the bypass valve, in which case the boost pressure becomes lower than normal.

The most expensive malfunction to fix is related to the failure of the balanced fuel supply system, which is located in the high-pressure fuel pump. If the synchronization device is faulty, the high-pressure fuel pump must be replaced. If the color of the exhaust has changed, there may be problems with the injection system, so its immediate diagnostics are necessary.