Whats wrong with my diesel engine? This one wins the prize! It is by far the most often asked question - both by email and on our forum. Whether it is hard starting, rough running, excess smoking, poor power output, or poor mileage it has become the major plague of diesel owners. I decided to nail this one on the head (since I am kind of tired of answering the same question over and over for the past 10 plus years.. :-)) and post my first troubleshooting manual on line for everyone to read!
I will break this manual down into 5 Chapters listed in order. I strongly recommend that you follow the sequence as it will be help you narrow down the problem or problems you are having without wasting time or spending unnecessary money.
Please note this web page is currently under construction:
If this is a diesel you have recently purchased or one that you have no maintenance records, I would highly recommend that you begin your fuel injection troubleshooting by removing and inspecting the fuel injectors. This is not a difficult job - but BEFORE you begin you will need some essential tools and supplies on hand.
You will need new heat shield washers when replacing the injectors:
https://mercedessource.com/node/3417Injector removal socket - needs to be a deep walled special socket:Torque wrench required for proper seating of the fuel injector to the heat shield washer:Injector return hose - this always breaks and must be removed when servicing injectors: