Miltek valve

[Tadass910]

Just wondering do you guys who have Miltek expierenced sometime that one valve is not closing correctly in a left side exhaust, after some time it closes automatically when driving, but let’s say when going from comfort to dynamic valve not opens correctly, and not closes correctly

[jipettersen]

Spring between the valve and the servo motor is out of position. Forcing the valve to "go its own way". Happen to me too. Easy fix.

[Tadass910]

Spring between the valve and the servo motor is out of position. Forcing the valve to "go its own way". Happen to me too. Easy fix.

Spraying wd 40 solved issues right away)

[dasquade]

From my own experience.....
So Milltek has this little spring underneat the valve "hidden" inside that little metal tube you can see when looking under the car.
This spring is used to push the valve a little bit upwards to give it tension so the valve doesn't rattle. The downside of it is that in the closed position the main actuator spring needs to be strong enough to push it downwards so it 'unlocks' as there is this very small but big enough lip inside the exhaust pipe.
I had it first on my left exhaust that the valve started to close and didn't wanted to open. Later on i had it on my right exhaust.
Decided to drill inside that metal tube and removed that little spring. Instant fix and now my valves doesn't have that resistance/lock.....same as OEM valve unrestricted play. I had contacted Milltek about this situation several times but didn't received help from them or advice, so decided to hack their design with luck.
All works good untill carbon enters it or the main spring is not strong enough to push the valve downwards.
The last thing i want is an exhaust system that blocks one or both pipes under load! Even tought it was a safety feature that the ECU (or exhaust module in my case) to open up under heavy load. Not sure if it could harm the engine but....anyway.
If interested i have some pictures of it or even movie about the differences somewhere.

[Nobby]

The valves aren’t made by Miltek - they are made by a German company called Kuster/Kuester. I know because I bought 2 valves off them to make my own exhaust.

They are the same as ones fitted to quite a lot of cars - mostly Audi, Mercedes and BMW.

[dasquade]

Yes, i'm aware of the fact milltek aren't making the valves themself (they mentioned to me). Just saying the valves are differently designed then the stock valves i had on my 2013 S exhaust (didn't had the additional upwards little spring and lock). Maybe 'oem' facelift valves has that same design and the actuator spring is stronger then prefacelift but those can't be purchased seperatly through audi.
Anyway, since i had it on both sides over a period of time (mostly due to use and carbon i think) they fail after a period of time.
I'm actually reinstalling my milltek tomorrow after i went to car inspection with my stock exhaust, so tomorrow i will know for sure if the 'hack' did the trick and valves are baby smooth functioning as the oem ones do (unmounted the milltek at least now open as smooth as oem compaired to lots of pressure before i removed the little spring).

Could be it is a different cause, yes the actuators actually dual spin twice every time you turn on the power to check their position etc....but a bit very unlikely the main spring could snap out of the baseplate from what i have seen. Additionally, before on the milltek i could really hear the valves scrapping metal when opening unlike the oem and hopefully tomorrow aswell soundless.

[Tadass910]

I'm actually reinstalling my milltek tomorrow after i went to car inspection with my stock exhaust

Why you can’t go to inspection with Miltek?

[dasquade]

I did when i was stage 1 and passed without them even noticing or ask questions about the milltek (let alone it is a 'non street legal' non res version). But since then i went catless + stage 2, no way i would pass emission test. So i ended up using my stock exhaust (less noise) and gutted the front silencers and added sport cats in those. Within emissions values now with that exhaust...but driving back with the milltek now .

[dasquade]

Oh, and back on topic....my milltek values working super perfect AND silent again now (by removing those small hidden 'lock' springs) .

[Tadass910]

I did when i was stage 1 and passed without them even noticing or ask questions about the milltek (let alone it is a 'non street legal' non res version). But since then i went catless + stage 2, no way i would pass emission test. So i ended up using my stock exhaust (less noise) and gutted the front silencers and added sport cats in those. Within emissions values now with that exhaust...but driving back with the milltek now .

Now it’s clear for me) I was thinking that you are only using catback, but if your Downpipes are cattles then yes you won’t pass it

[Has23]

I have a similar problem but probably worse with an added metallic rattle.

Any ideas?
I have a video of it but can’t figure out how to post it.

[dasquade]

When i was on my stock cats (identical as the rs6 cats by the way) i also had this very specific metalic rattle. Since i went catless i don't have it anymore or definatly not that much. At first i tought it were the wastegate flaps, as it is a dual port flap the flaps are slightly loose when not closed, but now i start to think it has something to do with the cats and the milltek 'resonates' the metalic sound even more.
Fact is, the millteks are the most aftermarket metalic/rough sounding exhausts...gotta love or hate it for that.

[Has23]

That’s exactly what miltek have said

[dasquade]

That’s exactly what miltek have said

...that it are the turbo wastegates?
Still odd if so that i dont hear it that specificly after catless :s

[Tadass910]

Concerning valve that not closes or opens properly:
When small exhaust does not heat up and you mainly send <beep> to the valves... so at the end it get clogged. Also I was told that this can happen if you drive small distances. Don’t know if it’s a true or not.