Mercedes M Klasse Diesel Glow Plug Issue

Sounds familiar I had a similar glow plug problem on my M Klasse Check engine light was on and the car was acting up on cold starts Is the car struggling to start when it's cold, or is it just the light and rough idle? It's like a bad tooth, you can feel it even when you are not biting down

Good analogy! Yes, it is hard to start when it's cold How did you resolve your issue? Did you replace all the glow plugs, or just the one that was faulty? And did it clear up all the symptoms, including the engine light?

I replaced all of them If one goes, the others are probably not far behind It fixed the starting issue and the engine light went off after clearing the code I'd suggest getting it checked at a workshop They can pinpoint the exact cause and replace what's needed

I appreciate the input Replacing them all at once makes sense I just got the car back from the shop They replaced all the glow plugs and cleared the error codes, and it's running smoothly again It cost me 440€, as estimated Thanks again for the help