How to fix Ford's leaking sound symposer on my Fiesta ST 

Good advice for the majority of us who have stock exhaust, and need the symposer to hear the boost. After cleaning it up, I suspect the symposer will work fine for a long time.

Useful vid, I'm on my second ST and noticed a rather strange sound and seemingly lack of boost and wondered (since I hadn't been bothered before) whether somebody had removed the symposer... They hadn't, but for whatever reason it doesn't make the sound that my previous one did so I'll be looking into these steps, since it's got a good 50,000+ miles on it over the other.

brilliant video! I disconnected the feed pipe to see what a symposer delete, would sound like and it's unbearably quiet, after seeing people saying on higher maps (mr230) boost leaks etc and seeing your video explaining you was loosing boost and how the delete gave you more boost again, I kinda thought I'm going to need the symposer delete and suffer with the insanely quiet induction, glad to see its fixable! and isn't actually a problem. keep up the good work!

That's interesting a lot of people are deleting / getting rid of the symposer because it's loosing boost pressure but I guess by design it's not supposed to do that, this is another solution if you don't want to loose boost but still enjoy the sound.

I don't even own a Focus or Fiesta ST and yet still found this very interesting!

nothing wrong with my symposer but curious about how it works so thanks

thx a lot for this very good video, i had some problems with the symposer and boost leakage as well and did the same thing to my st, and...it worked!!! you are a legend!!!

It's very useful movie. Now I know how this stuff works. Thanks!

You're the best commentator Well Done, great video

Thanks, i have around 58k km and i have noticed a lack of sound for a while now, gonna try this this weekend and fix this leak!!

Awesome , next weeks project sorted for me !

I'm actually going to do this to my ST as it does not sound as I remember from another ST's that I've ride in or driven. Looking forward to see if there is any changes soundwise.

I'll keep this in mind. Thanks

excellent video thanks

that's a very dirty part, lots of fluid. good thing you have you PPE ON!

Well done sir, very useful video!

Intsalled new word😀but great video😁

THANK YOU!!!!!!!!!!!!!!!!!!!!

Hi Mark, i have some troubles with my symposer that i would like to keep actually. I tried to clean it as you did but my problem is still there. I asked Ford to check it and they only agreed to blow some air in the tube which is going toward the windshield. Since then, something has changed. It's still not working properly but now i have some sound back around 4000 rpm at full charge. The thing is that it doesn't make this nice angry hornet sound the symposer use to do but more like the sound of a frog you squeeze with your foot haha. But at least it's the first time i see some changes. So my guess is that i have a problem specificaly with this tube. Maybe a leak, maybe a bad connection ? I was wondering, since you're the only one who made a very clear video of this system by showing us the inside and explain how it works, is there any chance you could make a video of where this tube goes exactly and how to dismount it ? From what i saw, the battery and its case need to be dismount ? But where this tube goes exactly in the windshield or the cabin ?? And of course if anyone else have an idea to help me solving this problem i take it. Just don't tell me to delete it haha EDIT : well i just realised that you're not driving a Fiesta ST anymore for quite a while...

Great video mate very interesting to learn how it works. I kinda like the sound symposer in my ST but don't like how it only activates when you put your foot down a bit. I wonder, If you make the tiny hole in the intake chamber larger, would that make the rubber vibrate more causing more sound in the cabin? I'm not an expert on this stuff just want my ST to have the cabin noise constant.

Thanks for your videos. I now know a lot more about what the symposer actually is and what it does in my ST180. Did you notice much of an audible difference when driving without a symposer? The audio on RU-vid makes them sound almost identical in your videos. It’s also interesting to see from your results that on some of your tests, a cleaned symposer provided higher boost pressures than the ‘Mountune Symposer Delete Kit’ Did you stick with the delete kit in the end? Hope all is well with the Mk3 RS.

Im gonna try this.

How can a fully sealed composer have different boost to a deleating kit? Both should have the same boost when the are completely sealed. In fact, the delete kit ensures constant boost, because it should never leak again like the symposer with aging rubber flaps.

Hi Have you got a video of when it was leaking for me to hear it please? Think mine may be as it has a weird sound just before the engine grunt kicks in on a 2014 focus st Thanks

Hi mate. Do i need the tape to do this? Just bought one i hate the drone tbh. Getting mp215 fitted tuesday as well

im going to the rr day at surrey 4th march if you want my old symposer of my st?

How much boost was you losing with the leaking symposer ?

what the heck is washing up liquid? what did you use , like a dawn dish soap or a spray degreaser?

Hi Mark. I know it's been a while since you've had your fiesta but I have a question for you. My car now had 50k miles on it and I think I have this symposer leak problem as it feels like it's losing power. I'm not sure if it's just in my head though. Thing is, I've also noticed my fuel economy gradually getting worse. Would this be a symptom of a boost leak or could it be something else? Hope you're enjoying your BMW. Awesome car BTW. Many thanks.

11:13 Are these runs in real-time, or have they been sped up? I feel like mine is slower (before and after delete kit). But I also haven't timed it. 4th gear, right?

I know how to fix it. Delete it like every other sane person. The symposer can cause boost leaks anyways.

its fake