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:

http://i68.tinypic.com/2mmwmdv.jpg

http://i66.tinypic.com/333fxqq.jpg

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.

Manifold flaps
 

Hi Andy,

Good luck, watching with interest. Manifold never taken off in my ownership from 60,000.

Regards

Richardracer

I was one of those S8s ! Couldn’t be happier, they really looked after me, completed the entire job and a couple of unexpected issues along the way. I would completely recommend VRS.

Do you have any equivalent pictures after the de-coke work / clean was done?

Unfortunately not, since the top of the engine and manifold was all removed to investigate a small oil leak, that's when the broken manifold flaps were discovered and I desperately tried to find a place that will do just the manifold work otherwise I would have taken the car to one of the previously mentioned places to get them to do the whole work.

Should have the car back this week so will immediately book it in with AMD Essex to get the carbon build up within the engine looked at (they do it in situ by hand). I'll ask them nicely if they can take some before/after pictures.

Ok thanks. I am interested to see the results with different cleaning methods and workshops. Here's my before and after

Just having the work done to gut the manifold has certainly improved the intake sound. Much deeper and throatier from in the car with the windows open or closed under any level of acceleration.

Next job is imminent, which is a decoke of the engine and a dyno/remap to tell the car how it should now be running, as well as tweaking to turn off the engine light which has come on due to the flaps being removed from the manifold, but that was expected.

I agree, the induction sound is slightly richer after the flap delete. I have also wired the exhaust flaps open on my stock exhaust which really add to the overall sound package.

Pleased you found a source for the decoke, not long now until she’ll be back to tip-top performance!

I was crawling underneath the rear bumper to tie the flaps open the next morning after I bought the car :ROFL: if there's one mod that S8 owners should be doing, it's this one. Had one pair of the centre silencers removed and replaced with straight pipe as well, which opens things up a bit more.

http://i68.tinypic.com/2wrnp1t.jpg

I can vouch for this mod, I had it done after seeing your report, what a difference it makes! Everyone says it's quite loud now, but I don't hear it in that luxurious cabin. It's great fun driving with the window down in places where I can hear it roar as it accelerates or that glorious cacophony of noise as blips and changes down under engine braking :love:

I have just spoken to VRS and they now charge £1500 +VAT for this job which includes BMC filter, gaskets, carbon clean (by hand), remap and dyno afterwards. I didn't think it would be so much but I will still get it done in the coming months.

I think its a good price to be honest, the remap alone is about £450 - they have done 3 of my cars so far so I know that's the remap price with dyne printouts, £1050 for the rest of the work is pretty good considering there is a lot involved. The difference will be huge when you get the car back, power is night/day different

Keep me posted on it mate +++

Well just got the car back after leaving it with them. I haven't had a chance to drive it properly as the traffic was horrendous and it was raining. So far, so good. VRS are a top outfit, Will explained it all and even helped save some costs on a couple of small repairs I needed/had asked for. I also had them fit a strut for me so car is now very good. I cannot comment on the sound yet as I had an exhaust leak prior to the work being done so it sounds quieter lol.

The 'package' doesn't include BMC filters, I may have mis-heard but I'm not actually bothered as it's only worth it if it is modded further. The power figures are actually around stock which at first I was disappointed with however he told me they are usually around the 400bhp tops when they come in but the car is a lot more 'driveable'. I will definitely use them again.

I just about caught mine in time, I had one flap broken and sitting inside the manifold. Could have been much, much worse. If you have a V10 and you haven't had this done, then unless you have had a new manifold fitted )or intend to) then get it done. You will only regret it later if not

I couldn't agree more, it's a ticking time bomb. Mine had two flaps lying over the inlets and I reckon one last drive with the EML light on would have seen the engine a write-off. Peace of mind for a fraction of the cost of a new manifold and no loss of performance isn't a difficult choice

Thats great news, did you get it dyno'ed after? I am hoping Will knocks some money off my next bill with them for all the recommendations ha ha

The difference for me was night and day

I did get it dyno'd. The figures were less than I expected, it virtually running stock figures now however it shows these cars either lose a lot over the years or never make what is on paper from factory. I don't care about the figures, the power curve is smooth and a much better drive. Need to take it for a decent drive today

Definitely! I now have peace of mind and can drive it as I please (within the law of course :ROFL: )