Mercedes X Klasse Diesel Stalling After Fuel Filter Replacement

Alright, so the check engine light and stalling, yeah, that's not ideal. A fuel pressure regulator issue on a diesel X Klasse could definitely cause those symptoms. The reduced power points that way too. Did the problems start immediately after you changed the fuel filter? An air lock in the fuel lines or a damaged pressure sensor during the filter change could be suspects. Have you scanned the ECU for error codes? Knowing the specific code would help narrow things down. A pressure drop could also indicate a failing fuel pump, but let's not jump to conclusions just yet. Have you noticed any engine misfire?

Thank you for your prompt response. Yes, the symptoms appeared shortly after the fuel filter replacement. I did scan the ECU, and it indicated a fuel pressure regulator malfunction. I am unsure if the pressure sensor was damaged during the filter change, as I was careful. As for an engine misfire, I have not specifically noticed any misfires. However, the engine is running rougher than usual. Is there a way to test the pressure sensor or regulator to confirm the issue before replacing any parts?

Okay, a fuel pressure regulator malfunction code pretty much confirms your initial thought. While you can test the pressure sensor with a multimeter, it's kinda tricky without knowing the correct values for your specific engine and year. Also, even if the sensor is reading okay, the regulator itself could still be the problem. Given the symptoms started right after the filter change, and you're getting that code, it's probably the regulator. I'd say at this point, it's best to take it to a workshop. They'll have the right tools and knowledge to diagnose it properly. It's possible you introduced air into the system, or maybe the new filter is faulty, but a proper diagnosis is the way to go.

I appreciate your guidance and expertise. I followed your advice and consulted a workshop. It turned out that the fuel pressure regulator was indeed defective, and the error stemmed from the fuel filter change, just as we suspected. The total repair cost was approximately 45€. Thank you for confirming my suspicions and suggesting the appropriate course of action.