Another V10 FSI carbon clean
 

A long post, I know, but there is a question at the end so please bear with me :o


I've half succumbed and half been forced to do the full decoking and intake manifold flap removal work on my S8 over the last couple of weeks.

I took my car to an excellent local specialist I always use, to investigate and fix a small oil leak. Turns out it was a small rubber seal just the diameter of a 2p coin on top of the engine's 'V' right at the back under the filter. Job done.

When the manifold was removed, a worrying sight greeted them and and they stopped work and called me over to have a look (I work literally across the road so they were happy for me to walk over any time). A horseshoe shaped piece of place plastic, which was part of the intake flaps within the manifold, was balancing on on the flap of one of the intake ports. It was a bit baked on to the port which suggests it hadn't just dropped out when they lifted the manifold off. It would surely be game over if that had fed itself to the engine's internals.

They got an endoscope into the manifold which confirmed the inevitable. The manifold flaps were $hagged and it was carbon galore in there. I then found myself in a tricky situation whereby places such as VRS in Northampton and AMD Essex will only undertake the whole work (manifold flaps, engine decoke and remap) and weren't interested in doing half jobs, which I suppose is fair enough. I was uncomfortable having the manifold put back on the car to start the engine and drive it somewhere to get the full work done, so took the manifold away and desperately tried to find a place to gut the manifold of its plastic flaps.

I read of a place on Pistonheads recommended by a few S6 V10 owners. 'JR Tuning' near Maidstone in Kent. From everything I read, they seem to know what they are doing and have endless S6s, RS6s, RS4s and a few S8s in for this exact work and more. I took the manifold down to them, collected it the next day (for an excellent price) and presented it back to my local garage to fix back on to the S8. They are all ex-Audi and VW master techs so aren't completely au fait with gutting a manifold as it's not exactly work that a main dealer will get involved with, but they all gathered round to gaze at the wonderful design of the gutted internals of the manifold :rolleyes:. Btw, Audi would be happy to relieve you of £3,100 for a new manifold and associated parts.

Anyway, JR Tuning gutted the manifold and removed the broken plastic flaps as well as the big metal chamber which houses them (the thing that looks like a foundations piling drill) so the manifold is now a hollow shell. The two actuators / potentionmeters on the front of the manifold are now obviously redundant and serve no purpose and have been unplugged and removed. They had thin metal arms connected to them which controlled the [now removed] intake flaps so my question is, should I plug them back in? I'm aware that I'll get the engine management light come on because of the manifold work but should I leave the actuators plugged in and just remove the control arms or leave it unplugged with an open connection?

I've had the car some time now and got away with only routine maintenance work so I've taken this opportunity to do the spark plugs/packs, air filters, rocker cover gaskets, replace the big air breather pipe (which can cause rough idle on a cold start if ruptured) and any other gaskets or pipes they come across plus the front belt. When the car is back together I will be taking it straight to AMD Essex who are happy to decoke the engine then custom remap the car.

FSI = F*cking Stupid Idea :eek3:

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I have PM’d you.

[/list]Two very good reusable quotes in the world of 8s. :cool:

How did you manage to persuade AMD Essex to do just the remap and decoke?

Just enquired about a decoke and nothing else, instead of going in with a full list problems and hoping they would gut the manifold. The tech I spoke to said they don't offer the flap intake manifold flap removal as a service anyway.

late to the party on this - both flap motors need to be retained, plugged in and not seized, although they aren't connected to anything it allows the ECU to think they are and operate accordingly. When VRS did my flap removal, deck, et al, they replaced the flap motors.

Hope this helps

I'm in a similar situation with my 2006 S8. I've taken a look inside my manifold with a borescope and the runner flaps are in a state of disarray, with two or three hanging down, along with the linkage between the two banks dangling attached at only one end, and the drive from the actuator is broken too so presumably they never move. This is no surprise as I have it on good authority that the manifold hasn't been taken off in the last 100,000 miles, and may well be the original with 173,000 miles on it now :eek:

In theory I shouldn't be able to sleep at night, but I haven't been able to find a story about flap problems actually damaging the engine. A few stories of bits of plastic being found on top of valves after people go looking for the cause of misfires, but no catastrophes. The only true disaster story I've found is this one, where the engine didn't survive a new manifold:

https://www.pistonheads.com/gassing/...&t=1586386&i=0

So I'm two minds about the risks of fixing it against the risks of leaving things alone, as the car gets me to the shops and back just fine ;)

Still, if I could take advantage of your searching around, did VRS say they were happy to do the whole job? I get the feeling I should probably take care of things.

If you call Will or Aaron at VRS and mention that Lee sent you, they should be able to sort you out, they are good guys there. 01604 705 247

They have done 3 S8s and an S6 on my recommendation and as far as I know, all are happy - I know I was.

I am not connected to them other than use them on my cars, specifically the TT now

VRS in Northampton are more than happy to do the whole job and come highly recommended by other forum members. It's when you want them to do part of the job, for example just the manifold flaps or just the engine carbon clean or just the remap that they aren't interested as they can't vouch for the quality of any related work that might have been done already but if they do the whole job then they know the car and it's all their own work.

Thanks, I'll get in touch.