Decoking...

[hussains]

Thanks Mac, good answer! You get my vote!

[pippyrips]

Right ive been thinking about the dreaded coking up issue. SO......

Audi developed and designed this engine,now correct me if i,m wrong but surely it was tested over thousands and thousands of miles both in a car and probably in a lab some where hooked up to all kinds of dianostic equipment?
So surely after extensive testing etc they stripped these engines down and inspect wear,tear deposits etc?? this must be common practice among all car/engine companies? to check on all kinds of perameters etc.

SO

If that was the case and i think it will of been and still is, Audi would have seen the carbon deposits on not just this engine but many others(FSI) and be aware of it?? This tells me they dont see it as a issue that can cause problems or surely they would not have dared develop the engine due to the financial backlash if nothing else.
I dont think this is causing the BHP issues although a lot of the discussion on this forum regarding BHP/deposits etc etc is a little above me as i am not techincally minded!!!

All i know is my car is quicker now than its ever been(17000miles) and long may it continue(que someone saying yeah but how long for??).
All i,m saying is i dont believe for one moment the VAG group has not carried out enough development on FSI engines as to not be aware of the deposit issues or be worried about them.

Nor am i an expert on rolling roads etc but i,d say if you took the engine from the car and tested it without drivetrain i bet it would be producing 400bhp end of(as long as it was maintained properly).

And finally,

If this is a long term problem why oh why are Audi using the same engine in the RS5?? Surely again if they were worried theyd develop a different engine???

Long live the RS4!!! ENJOY THEM WHILE YOU CAN.

The issue is definately affecting/causing a loss in BHP/torque to some degree. Simply looking at the ever increasing number of 'unoffical' pictures showing the inlet valves will tell you flow must be affected and the findings MRC made with my car back this up. Wether or not Audi chose to recognise this is another matter........I have also heard of a car where the build up was so bad it was causing one of the valves not to seal in the head

We still don't know just how quickly the build up occurs, how much it takes to impact performance and whether after a certain amount the performance drop levels off.

We should hopefully be able to answer a few of these soon as I'll be off to MRC again for them to measure buildup after 2kish, clean up where necessary, and fit a custom filtering/cleaning system that should solve this (for me a least ) once and for all.


As for why use the same engine in the RS5 - we have yet to see if they use the same EGR system and 'cyclonic separator..' and remember, DRC was failing a long time before the B7 appeared.

[mac4RS]

Simply looking at the ever increasing number of 'unoffical' pictures

Hey Pipps,

I would just love to see the 'official' ones taken on my motor showing that there is no problem, and all is okay and 'normal'.

But as yet they have not arrived - this is after a further 3 seperate e-mail communications today with my Service manager - I received three replys, but each time he avoided the same question...

In the end I had to phone (or drive to the dealership) to get a answer to the question. It was the same one again, ''I have no problems giving you this but it must be authorised by Audi UK''.

Don't these people just test you - are they hiding something... or just takin the

[RI_RS4]

FYI, for Audi to develop more power with the RS5 engine, something has to be different. It can't be only "increased airflow" from dual intake throttle valves and better exhaust headers, as has been reported, since the R8 has the same arrangement and does not develop any additional power. The word I've heard is that they will be using valve lift technology (VVT) in the RS5 V8. This would give them the ability to have a significantly different high speed cam profile. This might also allow them to utilize a bit of new technology to prevent valve deposits, if they wanted to.

As to why Audi did not see this in development. Well, many engines fail after extensive development periods. Dyno testing is not always equivalent to real world testing. Oil is often delivered from much larger storage systems, kept at carefully controlled temperature. Fuel is usually lab fuel that is supposed to be representative of fuel used in different areas of the world.

For most FSI engine owners, the only time they will even notice a problem with valve deposits, is when the engine starts up rough, hesitates or misfires. When they go to the dealer, they are usually told that "this is normal". We humans tend to become so acclimated to these flaws that eventually we dont' even notice them. It's only when you get into a different RS4 that you notice the difference.

[pippyrips]

Simply looking at the ever increasing number of 'unoffical' pictures

Hey Pipps,

I would just love to see the 'official' ones taken on my motor showing that there is no problem, and all is okay and 'normal'.

But as yet they have not arrived - this is after a further 3 seperate e-mail communications today with my Service manager - I received three replys, but each time he avoided the same question...

In the end I had to phone (or drive to the dealership) to get a answer to the question. It was the same one again, ''I have no problems giving you this but it must be authorised by Audi UK''.

Don't these people just test you - are they hiding something... or just takin the

I think this goes back to my point earlier, it wouldn't surprise me if it's because Audi are trying to avoid everyone wanting the insides of their engine looked at and being footed with a massive big.

Keep at it as they will have to show you eventually (just make sure it is actually your engine they show you!)

[chrissyr32]

Intresting write up by "TT TAME TECHNICIAN" on the VW/AUDI forum on pistonheads under title RS4 servicing.. have a read this guy i think is an audi tech seems to know what hes on about.. sorry dont know how to attach link....

[Oli]

http://www.pistonheads.com/gassing/topi ... mid=106961

[reevesroadster]

Im assuming nothing flags up on VAG-COM, including air/fuel mixture etc. ???

[P_G]

It appears this guy on PH is pretty much saying everything that I have been advised by my local master tech's.

[klauster]

I think im in the same boat as you Mac, but as yet, I dont seem to have got a dealership to take it seriously, will be contacting Audi UK tomorrow if the dealership lets me down again

[SR71]

VAGCOM will show you a flow through the engine that is about 5-8% down on a clean manifold.

I once had an Audi Master Technician diagnose a problem on my Audi S2 as a failed rear differential. Their quote of cost to replace: ~£5500.

In fact the solution was a failed centre propshaft bearing. Cost to replace: £23.50.

I won't name the dealer.

IMHO, Master Technician means very little these days. Just like they plug the diagnostic tool in, they feed us the Audi propaganda. To be fair, on the record, of course thats what they're going to do. Off record you might get a little more help.

Even more helpful would be a Technician who actually owns a B7...

[klauster]

Here is my dyno, following a 60k service...

[P_G]

Nick, your result doesn't look too disimilar to mine, just less power....

[klauster]

i can see what your saying but its still isn't right, and that was after a £500+ service

[Oli]

On the day, Nick's power curve flattened right off, far more horiztonal that the graph above