Ford SMAX Diesel Engine Running Lean

Hey, my 2020 Ford SMAX diesel is giving me headaches. It feels like the engine's running lean. I've noticed reduced power, the check engine light is on, and it's running rough with some jerking when I accelerate. Could a faulty injection valve be the culprit?

4 comment(s)

Interesting. A lean condition on a modern diesel like yours could stem from several issues. Has the car had any recent work? Are you using quality fuel? Do you know what the error code is? It might be worth checking the intake manifold and EGR valve for any carbon buildup.

No recent work, and I always use premium diesel. I don't have the exact error code, unfortunately. Carbon buildup... is that a big job to check?

Carbon buildup, while not ideal, is a common problem on modern diesels. However, based on your symptoms, a defective fuel injector is indeed a strong possibility and fits your vehicle's mileage. Without the error code, it's hard to be definitive. I would advise taking your SMAX to a qualified workshop for diagnosis before you start tearing things apart.

Thanks a lot for your input! Took it to the shop, and you were spot on – faulty injector! Cost me 515€ to replace. Runs like new again.

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