Five problems related to engine oil leaking have been reported for the 2003 Mercedes Benz C230. The most recently reported issues are listed below.
Engine harness and camshaft solenoids contaminated due to leaking oil which subsequently required replacement of O2 sensors.
The contact owns a 2003 Mercedes Benz C230. When the vehicle was started, it shook uncontrollably and the check engine indicator illuminated. The contact took the vehicle to the dealer and they stated that the engine oil was leaking and damaged the wiring harness and oxygen sensor. The repair would cost $2,000. The manufacturer stated that the vehicle was out of warranty; therefore, they were not responsible for the repair. The vehicle has not been repaired. The failure and current mileages were 40,000.
Check engine light came on. I took it to the dealer and they told me that the O2 sensor needs to be replaced, and the engine harness needs to be replaced. This is because the cam sensor leaked and pushed oil inside the harness and now there is oil flowing in the harness. This means everywhere there is a contact of the harness there is a possibility that there is oil on it. This seems to have become a common issue now and mercedes is ignoring it. I have noticed that I am getting bad mileage because of the bad O2 sensor. The irony is that the dealer will fix it with the same exact part number only to have it leak again in 4 years.
The check engine light goes on, the next day I go to independent mercedes shop. They tell me my O2 sensors are bad. The reason that they are bad because of the cam sensor at the top end of the motor was leaking. The whole time it was leaking I didn't even know. Then the bad new everything has been coated in oil such as O2 sensors that is it gives out the check engine light. The engine harness is also coated in oil.
Camshaft magnet leaking pushing oil through engine harness" harness, ecu, O2 sensors needs to be replaced. $3,700.