Mercedes Viano Diesel engine performance issue

That sounds rough I had something similar happen with my Vito, though it's an older model The hissing is what really gets me, that's likely an air leak somewhere Is your engine light on too Mine was, and the error code pointed to the intake manifold flap I'd check all the hoses connected to the air intake system really well before you spend too much money Maybe you'll get lucky and it's just a cracked hose How does the airflow control seem when the car is idling

The engine light is illuminated You mentioned checking the hoses Could you elaborate on the specific hoses I should inspect and any particular points of failure I should be looking for When you had this issue, were the symptoms intermittent, or were they consistently present

Okay, so the engine light is a big clue When I checked mine, it turned out to be a cracked hose right near where it connects to the intake manifold It was hard to see at first, I had to really feel around for it The hissing sound got louder when I pressed on the hose Honestly, after poking around for a bit, I figured it was above my skill level, so I took it to a workshop They confirmed it was the intake manifold flap control, just like the error code suggested If you're not comfortable doing the work yourself, it might be worth getting a professional opinion It could save you time and money in the long run

I appreciate your detailed explanation and advice Based on your experience, I will proceed with a thorough inspection of the air intake hoses as you suggested However, given the complexity of the system and my limited time, I am inclined to seek professional assistance I shall schedule an appointment with a reputable workshop to diagnose and rectify the issue Thank you once again for your valuable input