Partition / Tumble Plate

[RB1]

A question for the DIY'ers out there:

For those of you that have removed the flaps in the inlet manifold, did you then also remove the Partition plate (079 103 411 P)?

[RB1]

I thought with the way people are so passionate about if you should "de-flap" or keep the tumble flaps in, I expected at least one response!
Is everyone using Facebook groups/forums instead now, or is this still the best place for info?

I will elaborate a bit on my reasoning to leave the partition plates out....

So, like a lot of people at the moment, I have some time on my hands, and a fairly list of jobs on my RS4 that I never have time to get to.

I purchased my RS4 with 122,000 km on it here in Germany, and it had already had a carbon clean @ 100,000 km. I have since put 25,000 km on it, unfortunately with mostly cold starts/short runs/city driving. But, recently, the car has become difficult to drive in traffic/off the lights, and easy to make the engine stall. I had some implausible signal flap position codes, and some rough running.

I was surprised and a bit shocked at how bad it had become in 25k kilometers!

I used Brake cleaner and oven cleaner (wanted to try LIQUI MOLY Ventil Sauber, but delivery time was 2 weeks), flat head screwdriver, chopsticks, hard bristle toothbrush, rotary brush on the end of a drill, vacuum, a lot of heavy duty paper towel and 8 bar compressed air.
The oven cleaner was surprisingly good actually, and was better than the brake cleaner because after leaving it on for a few hours, it turned the carbon into a sort of slimy, gunky fluid, which was easy to remove with paper towel. I am really interested to know what fluid professional companies use when they do a chemical clean.

The potential reason for the "P2015 -008 Implausible Signal - Intermittent (Manifold Flap Bank 1)" fault code could be that was a lot of wear and free play between the plastic arm and the plastic gear on the tumble shaft.

https://youtu.be/XCnIKsblM1E

https://youtu.be/Ot5BaZGHfAQ

Only one of the arms was worn, the other was absolutely perfect, which is unusual, because they do the same amount of work. So, for me, it was worn because it was misaligned when it was built from the factory or when it was apart during the last carbon clean (i have no way of knowing). When you move it by hand or with a vacuum hand pump, you could see that it was also pulling to one side and not really following the stroke of the pneumatic actuator. I released the 2 fasteners, bent the bracket slightly, and re-tightened again.

I used Würth PLASTIC ADHESIVE REPLAST EASY UNIVERSAL part glue to bond the arm to the gear and shaft. The surface needs to be rough. If I want to remove this again, I will just need to use a heatgun to de-bond it.

The decision to "de-flap" the manifold or not, was made for me. I did not have the correct Loctite to refit the screws back on and I wanted the car mobile again relatively quickly. I was not going to take a risk with the wrong loctite. I used the 034 Motorsport guide for fitting their Billet arms for info, and they recommend Loctite 290. If someone recommends something else, or can confirm what the factory uses, please let me know.
What I did notice, which is a little worrying, is that some flap screws felt OK, and you had to break the Loctite before they moved, but some came out pretty easy. too easy in fact... it was clear that the ones that came out easy (no snap or crack from the loctite breaking) had much less loctite on the thread. Again, I cannot say if this was from the factory, or if it was from the previous carbon clean.

I would actually prefer to have them in, because i tend to drive in the more usable low rpm anyway. I do notice i have a slight hesitation now with light throttle and low RPM. For me, there is no point in talking about comparison of flaps in or out at the moment, because I am sure that the carbon was having a much bigger influence than anything else. The engine (and car) now have a completely different character. It starts easier, idles better, pulls away from idle better, drives smoother, and obviously feels more powerful. it really wants to rev now also, whereas before, you didn't really notice it felt restricted. This carbon buildup happens so slowly that i guess we just don't notice the performance incrementally dropping.

Anyway. the main question in this post was what have others done with the partition plate in the cylinder heads when they have removed the tumble flap. As I see it, the whole point of the plate is to work in unison with tumble flap during the stratified charge operation for low rpm/low throttle position. So if you remove the flap, then you can also remove the partition plate, because it serves no purpose anymore. I accept that the stratified charge operation will be worse now, and the homogeneous operation at high rpm/high throttle position will be better.
If I am wrong, somebody knows or has tested with and without, i am interested to hear your thoughts and results.

Now that the carbon cleaning job is done once, I would do it again, and do it more regularly. However, there are some things I have done/would do to make my life easier:

1. Either find out the correct chemical that professionals use, or buy a walnut blaster kit. They are not so expensive, but it seems they make a mess. In the US they sell 3D printed parts for your vacuum and walnut blaster nozzle to go into, reducing the spillage. 034 Motorsport also sell something like this in billet Ali.

2. I already changed the screws for the PCV valve bracket. I put hex key bolts in from the front, and nuts at the back, so you just need to hold it from behind and work from the front.

3. I fitted a jubilee clip on the water pipe that attaches beneath the fitting between the PCV outlet and the inlet manifold. It is much easier to remove this pipe now with a long extension than with the standard hose clip. (picture attached below of the fitting from the top, you cannot see the jubilee clip fitted on the bottom, but you get the idea which part i am talking about)

4. On the same topic, I found that JHM in California sell a bypass kit (https://jhmotorsports.com/jhm-oil-separ ... si-v8.html) for this, which would make the inlet manifold removal job even easier but they are using it to stop the coolant from heating up the inlet manifold. It would be interesting to have a thermocouple sensor in the inlet manifold to see if it really does do anything.

5. I would like to remove the plugs that give you access to the screws for the flaps, and replace with shallow head hex key bolts. This will allow access to inspect the condition of the carbon on the valves and also check torque of the screws. Actually because of the grade of the Loctite, you should only really lightly check the torque to see if they have come loose. paint mark would be a better idea to visually see if they have moved.

I am interested to hear if anyone else has noticed this hesitation at low RPM and if there is another solution for it. Maybe it goes away when i put the flaps back it again.

Now, I need to get around to the rest of the jobs!

[12th]

Post de-flapping (mine was part of work at MRC) the car isn't quite so metronomically smooth at low revs when cold, but it's not too much of an issue. I've nothing to add technically, but I'm impressed with your work and write-up!

[Bill'sRS4]

A very well written and comprehensive account there, well done.

[cherub72]

From memory there is a kit to replace the nasty plastic arms on the spindles with metal ones. My local indy was telling me about it recently when I was asking about a decoke. Contact details for the indy are on http://www.audivwsc.co.uk, speak to Peter, he's really helpful.

I was watching a video about this and what chemicals to use yesterday on an S6 V10 but the setup looks the same https://youtu.be/8zmXyB38mRg

[RB1]

From memory there is a kit to replace the nasty plastic arms on the spindles with metal ones. My local indy was telling me about it recently when I was asking about a decoke. Contact details for the indy are on http://www.audivwsc.co.uk, speak to Peter, he's really helpful.


I was watching a video about this and what chemicals to use yesterday on an S6 V10 but the setup looks the same https://youtu.be/8zmXyB38mRg

RE: metal arms
My guess is that he is probably talking about these: https://store.034motorsport.com/intake- ... l-fsi.html
I used their helpful .pdf guide that that they provide online to strip and rebuild mine. They have a 10% off sale at the moment, and the Euro is strong to the Dollar, so it is maybe a good time to buy a set.

RE: S6 V10 Video
Thanks, I had not found this one.

I don't know about you guys, but i am not a fan of cleaning with a wire brush, I would be worried about wire falling out, and not spotting it!

Here in Germany, they all speak about BeDi cleaning (Betriebsbedingte Reinigung ), and I can find this company:
https://www.lambda-deutschland.com/bedi-zusaetze, but its the same story as the "BG Air Intake Valve & Cumbustion Chamber Cleaner" that you found, it seems it is not for sale to the general public.

[RB1]

Small update on the hesitation I had @ low RPM after i did the carbon clean and removed the tumble flaps.

Because it was bothering me so much, i started to look into other things that might also cause it. I can imagine that if my DMF + Clutch is still the original unit (~148,000km), and the engine was not running smooth, then the problem could be exaggerated with a worn flywheel (by worn, i mean springs that have lost some of their tension). I was also thinking that it could be 1 or more injectors, and of course it could all be just down to the tumble flap being removed also...

When I did the carbon clean, I deleted the learned fuel trims before driving, so I had more or less ruled out software. However, before i started ordering flywheels or injectors, I tried a throttle body reset, and this did a truely massive improvement in drivability. to try to put it in perspective, I would say the drivability issue that I had was something like 80% better.

For info, I more or less followed this procedure:

viewtopic.php?f=35&t=124222&p=914099&hi ... et#p914099