Mokka's Power Loss & Hissing: Intake Leak Warning Signs?

Hey there! I actually had a really similar issue with my 2016 Vauxhall Astra diesel (I have some experience working on cars, but I'm no expert). Those symptoms sound exactly like what I dealt with – especially that hissing sound! Turned out my intake hose had a small crack and was leaking. Took it to my regular workshop, and they spotted it pretty quickly. Got it replaced, cost me about €100, and all those problems disappeared right away. The engine light went off too. Before I share more details though – can you tell me if you've had any work done on the engine recently? Also, what's your mileage? This could help pinpoint if it's the same issue. Hope this helps! Let me know if you need any more info.

Hey, thanks for sharing your experience! I've got 59943 KM on the clock and just had my service done last month. Your Astra situation does sound very similar to what I'm experiencing. It's a bit reassuring to hear it might be something relatively straightforward like a cracked intake hose rather than a major engine problem. Did your mechanic mention whether this is a common issue with Vauxhalls? I might just take mine to the garage tomorrow to get it checked out. A €100 fix sounds way better than what I was imagining! Let me know if you discovered any other potential warning signs I should look out for.

Hey again! Yeah, when I had my Astra checked, my mechanic actually mentioned it's fairly common in Vauxhalls, especially once they hit the 50-60K mark. Mine had about 65K when it happened. In fact, he told me he sees this issue pretty regularly in both Astras and Mokkas – something about the rubber compounds they use for the intake hoses becoming brittle over time. One thing I forgot to mention in my first reply – before the hose completely failed, I noticed the problem was worse on cold mornings. The hissing was more pronounced when the engine was cold, and it would sort of "settle" after warming up (though never completely go away). Did you notice anything similar? Also, here's a tip: when I was trying to diagnose it myself, I sprayed some soapy water around the intake area while the engine was running (carefully!), and the leak was pretty obvious from the bubbles. Though honestly, given your symptoms are so similar to what I experienced, I'd just head straight to the garage. €100 was totally worth it to get my car running smoothly again. Keep us posted on what they find! I'm betting it's the same issue.

Thanks so much for all that detailed info! You've definitely made me feel better about the whole situation. Yes, actually! Now that you mention it, I have noticed it's worse in the mornings. I usually warm up my car for a few minutes before driving off, and the shaking does seem to calm down a bit after that. That's really interesting about the rubber compounds, makes total sense why it would happen around this mileage. I think I'll skip the soapy water test and just take it straight to my mechanic tomorrow morning. You've convinced me it's probably the same issue, and I'd rather let the professionals handle it. I'll update the thread once I know what they find. Really appreciate all your help and insights! It's great to hear from someone who's been through the same thing.