Mercedes X Klasse Diesel EGR Valve Issue

Whoa, that sounds rough I had something similar happen with my X Klasse diesel Check engine light was on, and the car felt like it was struggling to breathe Fuel economy went down the drain I'm no expert, but it sure sounds like EGR valve issues Was the hissing sound constant, or just during acceleration

The hissing sound is most pronounced during acceleration, particularly when the engine is under load It seems to correlate with the jerking sensation I'm experiencing Did you notice any smoke or rough idling in addition to the reduced power and check engine light

Yep, the smoke was definitely there, especially on cold starts And the rough idling made the whole car shake sometimes It's almost certainly the EGR valve, just like I suspected I'd suggest getting it checked ASAP Continued driving might risk further problems with the catalytic converter Taking it to a workshop is your best bet

I appreciate you confirming my suspicions It's reassuring to hear from someone who has faced a similar situation I have scheduled an appointment with a trusted mechanic They confirmed it was the EGR valve and replaced it The car is now running smoothly again Thank you again for your help