Peugeot 806 VANOS Failure

VANOS on a 2001 806 is a bummer. Check engine light and fuel consumption point to something amiss. Have you checked the camshaft solenoid valves? A defect or power supply issue could be the cause. Has the car been sitting unused? Does the engine sound rough or misfire?

Is there a way to test the camshaft solenoid valves myself, or is that best left to a professional? The car is used regularly. I haven't noticed any obvious misfires, but the engine doesn't sound as smooth as it used to.

If the engine sounds rough and you're not comfortable testing the solenoids, take it to a workshop. It sounds like the VANOS is the problem. A professional can diagnose it and replace parts. I had something similar happen and the repair cost was around 250€.

Turns out you were spot on! It was a faulty camshaft solenoid valve. The workshop confirmed, replaced the valve, and cleared the check engine light. The engine is running smoothly, and fuel consumption is back to normal. The repair cost was almost exactly as you predicted, around 250€. Thanks again!