Mercedes R Klasse Engine Misfire Resolved

That sounds like a pain! I had a similar issue with my Mercedes, same model. Misfiring can be tricky. Rough idle, check engine light, and jerking are classic signs. Have you checked the ignition coils? I had one go bad, and it caused similar symptoms. It could also be the fuel pump struggling to deliver enough fuel, especially under acceleration. Before you jump to injectors, maybe rule out the simpler stuff first. If it's not plugs or coils, a compression test might be a good idea to see if you have any issues with the cylinders themselves. Let me know what happens!

Thanks for the quick reply. I'll definitely check the ignition coils more closely. When you say 'similar symptoms', did you also experience reduced engine power? And how did you eventually figure out it was the ignition coil? Was it obvious when you inspected it, or did you need to use some diagnostic tool?

Yeah, I had reduced power too, especially uphill. It felt like the engine was holding back. For the ignition coil, I used an OBD2 scanner that pointed to a specific cylinder misfiring. Then I swapped the coil from that cylinder with one from another cylinder. The misfire moved to the new cylinder, confirming the bad coil. But honestly, unless you have a scanner, it's a bit of trial and error. Given the possible causes, maybe it is better to go to the repair shop.

Thanks a lot for your help! I took it to the workshop, and they confirmed it was indeed an injector that was defective, as I initially suspected. They replaced the injector, and the engine is now running smoothly again. The repair cost came to 515€. I appreciate the advice!