Peugeot 408 knocking sound under load

I'm having a frustrating issue with my 2012 Peugeot 408, gasoline engine. It's got about 48226 km on it. Lately, I've noticed a distinct knocking sound, almost like a combustion knock. It's most noticeable when the engine is under load. Alongside the noise, I'm experiencing reduced engine power, a jerking sensation when accelerating, and even some smoke coming from the exhaust when I really put my foot down. I also hooked it up to a code reader and found an error stored in the error memory, but didn't write it down. I'm suspecting it might be related to deposits in the combustion chamber. Has anyone else experienced something similar with their 408?

4 comment(s)

I have a 408 too, and I had very similar symptoms a while back. Knocking, jerking, loss of power... it sounds like exactly what I went through. Did you notice if it was worse when the engine was cold?

Yes! It's definitely worse when the engine is cold. Once it warms up, it's still there, but not as pronounced. What did you end up doing to fix it?

Okay, that sounds even more like what happened to mine. I strongly suggest you take it to a workshop; it sounds like there could be something seriously wrong. It could be something like you said with the deposits in the combustion chamber, but you don't want to risk further damage.

Thanks for the advice! I appreciate you sharing your experience. I took it to the workshop, and you were right. They confirmed deposits in the combustion chamber. They performed an engine tuning, costing 425€. Now it is all good!

Join the discussion now: