Berlingo engine smoke and power loss

I had similar issues on my Berlingo. A faulty crankcase ventilation can leak, causing unstable idle and those symptoms. Have you checked the valve for damage or buildup?

Where exactly is the crankcase ventilation valve located in the engine compartment? I want to inspect it but don't know where it is.

It's tricky to pinpoint without a diagram. Given the symptoms, I'd suggest a technician. It's likely a defective valve that needs replacing, saving time and preventing more problems.

I consulted a workshop as you advised. It was the crankcase ventilation. The repair cost 360€. Thanks for confirming my suspicion.