sarah_koenig2

Mercedes GLA diesel engine issue

I'm hoping someone can shed some light on an issue I'm having with my 2020 Mercedes GLA diesel. It's got about 60699 km on the clock. Recently, the check engine light came on, and I've noticed a distinct loss of power, especially when accelerating. Also, I've seen some smoke coming from the exhaust when I put my foot down. From what I've read, it sounds like it could be a problem with the crankcase ventilation valve. Could a defective PCV valve cause these symptoms? I'm trying to keep up on my maintenance but emissions issues are new to me. Any ideas? Could a leak be causing this? Also, the idle seems a bit rougher than usual.

4 comment(s)

The symptoms you describe are consistent with a crankcase ventilation issue. A malfunctioning PCV valve can indeed lead to reduced power and smoke, similar to how a clogged artery restricts blood flow. Is the oil filler cap difficult to remove when the engine is running? This could be another indicator.

Thanks for the quick reply. I'll check the oil filler cap tomorrow when the engine is cold. If the cap is hard to remove, does that confirm the PCV valve is the culprit? And could this also affect my fuel economy?

Difficulty removing the oil filler cap strengthens the likelihood, but it isn't definitive. A diagnostic scan would provide concrete evidence. Fuel economy can suffer due to incorrect air/fuel mixture from the leak. I would advise a workshop visit for proper diagnosis and repair to avoid further complications.

Thanks. I appreciate the help. I took it to the workshop, and it turned out to be exactly what we suspected: the crankcase ventilation valve. The total repair was around 360€. Runs like new now!

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