GLC poor performance and misfire after starting

My 2018 Mercedes GLC with a gasoline engine is showing some concerning symptoms. Mileage is at 90065 km. Starts are rough, fuel consumption is up, engine power feels reduced, and idling is uneven, sometimes stalling. I suspect it's related to a defective injection nozzle, possibly clogging. Could this be causing the misfire and emissions issues?

4 comment(s)

Sounds familiar. I had similar issues with my GLC. Rough idle, definitely noticed a drop in performance. Have you checked for any error codes? Could be related to the injection system. Dirty injectors are a common culprit. What's your driving style like? Lots of short trips?

No error codes showing currently, but symptoms persist. Driving style is mixed, both short city trips and longer highway runs. How did you resolve your issue? Did you try any fuel additives or injector cleaners before replacement?

I tried fuel additives, but it didn't solve the problem. Eventually, I had to get the injectors replaced. Bit the bullet and took it to a workshop. They confirmed the injector issue. It's a job best left to pros, especially with the high-pressure fuel system. Cost me around 500€. Get it checked before the emissions become a bigger problem.

Thanks for the input. I appreciate the info. I took it to the shop, they confirmed the injection nozzle was defective and causing the clogging. Replacement done, total cost 515€. Performance is back, and idling is smooth again.

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