Have Mercedes Questions? Ask a Mechanic for Answers ASAP
HiCustomer anytime you have a hard start on a diesel you've got to first check or replace the glow plugs. Without the heat from the plugs the cold cylinder walls will absorb the heat of compression and it can take forever to start if it starts at all in cold weather. I'd start by making sure you have power to the glow plugs. If you have power to the plugs I'd test or replace the plugs. If you have no power to the plugs I'd check the fuse for the glow plugs and test the glow plug relay. Let me know if you have any questions.