Vanette intake manifold flap issue

Hey there! I had something eerily similar happen with my Vanette. Same symptoms: reduced power, rough running, the works. That hissing sound is a telltale sign. I'd put money on your intake manifold flap control being the culprit. When that flap doesn't regulate the airflow properly, your engine is going to throw a fit. I bet if you hooked it up to a diagnostic computer, you'd get a code related to the intake manifold flap. Have you checked for any error codes yet?

Thanks for the quick reply! I haven't hooked it up to a diagnostic computer yet, but I was planning to. Good to know the hissing sound is a key symptom. Did you try any DIY fixes, or did you end up taking it to a mechanic? Also, do you remember what the error code was, if any? I'm trying to get a better idea of the scope of the repair before I commit to anything.

Honestly, I fiddled around with it for a bit, checking connections and stuff, but I didn't want to risk making things worse. In the end, I took it to a trusted workshop. They confirmed it was the intake manifold flap control, and they replaced it. I think the error code was something like P2015, but don't quote me on that. The repair cost me around 465€, including parts and labor. If you're not comfortable working on it yourself, I'd strongly suggest taking it to a professional. It's a fiddly job, and you don't want to mess with the airflow system.

Thanks so much for sharing your experience! Sounds like my symptoms are a match. I think I'll take your advice and get it checked out by a workshop. Knowing the potential cost and the likely cause (intake manifold flap control) helps a lot when talking to them. I appreciate the help!