In Summary

Occasionally the engine on your Mercedes Benz experiences a damaged balancer shaft kit which retards engine timing and causes erratic poor engine performance.

Hey Paul, I recently bought a used Mercedes Benz ML 350 4matic from Japan with 160,000 kilometres. As soon as I started driving it, I noticed it had a check engine light on the dashboard. We have serviced the engine but the fault persists. My friend’s mechanic says we may have to remove the engine to fix this problem. I have noticed that its engine performance is erratic. What could be the problem? Andrew Katende.

Hello Andrew, the check engine light means the Mercedes should be inspected for an engine emission fault. There are a couple of factors that will directly affect emission which include ignition system, fuel system and air intake system. These should be inspected using a computer diagnostic tool and faults assessed to determine cause of check engine light. Common causes are faulty heated oxygen sensors.

Occasionally the engine on your Mercedes Benz experiences a damaged balancer shaft kit which retards engine timing and causes erratic poor engine performance. That would require a replacement of the balancer shaft kit and possibly replacement of the engine timing chain kit. Perhaps this is what that mechanic is suggesting.

A computer diagnosis will definitely help you rule out the balancer shaft / timing fault or confirm its presence. Replacement of the balancer and timing kit would require to remove the engine for easy access to the timing case and camshafts and replacement of faulty parts with genuine Mercedes components.