2009 Volvo S40 Diesel Experiencing Engine Issues, Potential Swirl Flap Control Error

Hey there, good to meet you. I had a similar issue with my 2012 Volvo S60 a while back. The symptoms you mentioned point exactly in the direction of a swirl flap failure. It's quite a specific issue, but once it hits, it's unmistakable. Now, I'm not a mechanic, but from what I understand the swirl flap's job is to manage the air/fuel mix and when it breaks, you get all sorts of engine performance issues - shaky idle, the hissing sound, power loss, the whole shebang. When mine broke, the car was driving like a donkey on roller-skates for sure. I took it to a garage, and they confirmed it. They had to replace the entire intake manifold, as the swirl flaps are integrated into it - meaning they had to disassemble a good chunk of the engine and put it back together afterwards. It wasn't a quick fix, but it resolved all the issues. Sounds like you could be dealing with a similar thing. Not going to lie, it’s a hefty bit of work, but most good garages should be able to do it. Just make sure you do a bit of research and find a mechanic you trust - it made a world of difference for me. Good luck!

(Translated from German)

Hey there! Your situation sounds awfully similar to my experience with my 2011 Volvo S40. I had the exact symptoms and it turned out to be a swirl flap failure alright. Had a trusted mechanic replace the entire intake manifold, and it was indeed quite a project. Curious though, how much damage did it do to your wallet, if you don't mind me asking? And have you encountered any other issues since the repair, or has it been smooth sailing so far? Cheers!

(Translated from German)

Hi again! Ah, the old wallet damage question, eh? Well, truth be told, it was not the most budget-friendly repair. Fixing the broken swirl flap set me back by around 865€, but it definitely resolved the problem. Bit of a pinch, but considering the extensive work they needed to do, I suppose it was justified. After tackling the swirl flap control issue, it's been pretty much smooth sailing since then, my Volvo's been purring like a kitten. Haven't seen that engine light come on or experienced any of the other issues since. In other words, post-repair, it's been a breeze driving. Knock on wood, right? Hope your ride is doing well too. Cheers!

(Translated from German)

Top lad! Thanks for sharing your experience . That kinda confirms my swirl-flap suspicion, looking at how similar our issues were. Sounds like a proper meaty job for the mechanic, but seems there's no two ways about it, right? Also, while that repair price makes me wince a bit, I guess it's better than a continuously failing car, isn’t it? It’s a relief to hear that your ride’s been behaving well since the fix. Just what I needed to hear for a bit of courage. Hoping my old Swede will purr smoothly again soon too post repair. Appreciate the time you took to reply and fingers crossed for continued smooth sailing for both of us. Cheers!

(Translated from German)