andreascrystal1

Mini Cooper Diesel Engine Power Loss

I'm at my wit's end! My 2018 Mini Cooper Diesel has developed a proper nasty fault. The check engine light's on, and it's like driving a snail! Reduced engine power is a massive understatement, engine response is terrible, and I'm sure I'm using more fuel than I should. I reckon it might be a defect in a vacuum switching valve, but I am no expert. Has anyone had similar issues, and if so, any ideas what to check before I throw money at it?

4 comment(s)

Sounds familiar! I had something similar happen with my Mini, though it's not the same year. Check engine light, felt like I was towing a caravan, and the fuel gauge was dropping faster than a stone. I'd put money on a vacuum leak somewhere. Have you checked the boost controller or any of the vacuum lines? Is the turbo lag particularly bad?

Boost controller, vacuum lines... right, okay. Where exactly should I be looking for this vacuum leak? And is there a way to test the boost controller, or the pressure sensor for that matter? I'm not exactly a mechanic, you know!

Honestly, tracing vacuum leaks can be a pain without the right tools. My issue turned out to be a split hose. If you aren't confident get it to a shop, they'll smoke test it and find any vacuum leak. It could also be the bypass valve sticking, but a faulty vacuum switching valve definitely sounds like the most likely culprit given the symptoms. Best get it checked properly before you start replacing random parts.

Just wanted to let you know I got it sorted! Took it to a local place, and they confirmed it was a dodgy vacuum switching valve, just like you thought. Cost me 140€ all in. Runs like a dream now, no more limp mode! Cheers for the help!

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