erwin_sky6

Skoda Citigo Engine Knocking Issue

I'm at my wit's end with my 2015 Skoda Citigo, gasoline engine. It's got about 249511 km on the clock. Lately, it's developed this awful knocking sound, like something's about to explode. I've noticed a real drop in engine power, and it's jerking like crazy when I try to accelerate. And get this, it's puffing out smoke when I put my foot down. Plugged it into a code reader, and yeah, there's an error stored in the error memory. I'm thinking it might be deposits in the combustion chamber causing all this ruckus. I've been using regular fuel, could low fuel octane be the culprit? Could it also be piston slap?

4 comment(s)

Sounds nasty! I had something similar happen with my old Renault Megane. Reduced power and jerking, though no smoke. Turned out to be pre-ignition. Have you checked your knock sensor? Is it throwing any codes related to ignition timing?

Pre-ignition, huh? Interesting. So, the knock sensor, I've seen it mentioned. How does that relate to the ignition timing being off? Is it like the sensor is supposed to tell the car to retard the timing when it detects knocking?

Yeah, the knock sensor tells the ECU when it detects engine knock, and the ECU retards the ignition timing to prevent damage. If the sensor is faulty or the ignition timing is seriously out of whack, it can cause pre-ignition, which is basically uncontrolled combustion. But with the smoke and the error code, deposits seem more likely. I'd get it checked by a workshop, they can scope the cylinders and see what's going on.

Okay, thanks a lot for sharing your experience. I took it to a local mechanic, and you were spot on. They scoped the cylinders and found excessive carbon buildup. They did a combustion chamber cleaning, and that cleared up the knocking. New spark plugs too, just to be safe. Cost me 425€, but it's running like new again. I'll definitely be more mindful of fuel octane from now on.

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