Renault Spider check engine light VANOS issue

VANOS issues on those Spiders can be tricky. That check engine light and fuel consumption definitely point in that direction. It could be the VANOS solenoid valve itself, or perhaps a wiring issue supplying power to it. Have you noticed any low power, especially at lower RPMs?

I have felt a slight decrease in power sometimes. If it's the solenoid valve, is that something I could potentially fix myself, or am I better off taking it to a professional? And how can I check if power is available?

Yeah, the power loss confirms it more. Look, messing with the VANOS without proper tools or knowledge can lead to more problems. Given that, and from my own experience, I strongly suggest you visit a workshop. They can diagnose it properly and replace the solenoid if needed.

I took it to a workshop this week. Turns out you were right. It was a defect in one of the camshaft solenoid valves, the power supply was OK. The total repair cost was 250€! Thanks again for pointing me in the right direction, saved me a lot of headaches!