Carbon clean

[sckrs4]

Guys

What will happen if you don't do the carbon cleanup? Would the engine pack up around 100k miles?

The pictures look a real mess! Is this the entire Audi fsi range?

Shouldn't Audi spend a bit more on R&D to come up with a fix?

Has anyone approached Audi UK directly on this issue?

~

[adsgreen]

It's a natural byproduct of direct injection engines - all manufacturers have it.
I'd guess that the b8 and rs5 are better. It's known that running the engine hotter can help and if the problem is valve overlap then a subtle tweak can help there.

As for the rs4 b7 - it's self limiting. Plenty of cars never been cleaned and the carbon returns pretty quick.

[TAB1S]

Hi guys how difficult are we talking on a scale of 1-10 i like to think im half about, did a lot of motocross growing up maintained my own bike etc 2 stroke mind so a few leagues apart, keep the golf up together service wise.
Just a bit worried as alot of moneyz if things go t!ts up.
Thanks

[S4Player]

Guys

What will happen if you don't do the carbon cleanup? Would the engine pack up around 100k miles?

The pictures look a real mess! Is this the entire Audi fsi range?

Shouldn't Audi spend a bit more on R&D to come up with a fix?


Has anyone approached Audi UK directly on this issue?

~

Engine will blow up resulting in an insurance write off. Happened many times in my head but never actually happened in real life

[sync24]

What will happen if you don't do the carbon cleanup? Would the engine pack up around 100k miles?

The pictures look a real mess! Is this the entire Audi fsi range?

Shouldn't Audi spend a bit more on R&D to come up with a fix?

Has anyone approached Audi UK directly on this issue?

~

The engine won't pack up - the engine will just gradually go down on power/efficiency to a point that it will go into limp mode.
If your car has 100K on the clock and has never had a carbon clean I would strongly recommend that you get it done - the difference it makes is like night versus day - The usual suspects, MRC, AMD, Unit 20 & Revolution all offer a service to get it done in a day - around £500 - I consider it to be an annual service task

There is no fix for it - it's a design flaw with the FSI engines as there is no actual fuel flowing over the valves - It just seems to be that the 4.2 V8 suffers more from it

[orangepeel]

Just wondering would another injector unit be possible placed on the intake some were so a small amount of fuel passes over the inlet valves to help with carbon build up or if it would be possible or has anyone tried or any knowledge of it

[adsgreen]

This I how the Toyota GdI engines work - they have both direct and indirect fuel injection and the Ecu simply occasionally uses the indirect ones (say 1 in 100 revs - not accurate but you get the idea).

The causes as to why the rs4 engine is so bad is still yet unconfirmed. Valve stem seals and internal exhaust gas recirculation are likely candidates which can be sorted in later versions. If love someone to crack open a more recent v8 to see what the build up is like.

Also the r8 doesn't suffer as bad as the intake to the cylinders is dead straight (as it has plenty of headroom over the engine in the rear bay). So maybe a tweak to the intake manifold would help.

As for fitting a third party fuel injector... Possible but would be difficult to get 100% in sync with the Ecu.
Water meth seems to have some benefit - a SA Kenner had some great pictures post install.

If you had a detergent additive that could survive combustion then it would be useful.
Or maybe a variable thermostat the get the engine really hot now and then (or drive it like you stole it!)

[orangepeel]

Mines in next month for a carbon clean. at 77500 miles as I dont think it's ever been done. So there will be a big build up of carbon. So I should see a big difference in power

[sync24]

To quote Doug @ MRC 'Take it to the limiter at least once every trip once it's up to temp" - sounds a plan to me!

[jaysrs4]

What I notice the most is that if I take it out the garage and put it back in for some reason, without actually driving it anywhere, the oil buildup is so noticeable when I start it again.

Take it out for a drive and boot it for the first time, you can see it clear its throat and never does it again, even on a cold start the next day or whenever.

I just took it out the garage today for a fiddle and put it back in when it started to rain, I can guarantee it'll be a bit smoky when I start it again. I usually make an excuse to take it out if I start it, not running it up to temperature must contribute to carbon build up.

[orangepeel]

I always hit limiter regular it would be rude not to : ) :bigblink:

[adsgreen]

What I notice the most is that if I take it out the garage and put it back in for some reason, without actually driving it anywhere, the oil buildup is so noticeable when I start it again.

Take it out for a drive and boot it for the first time, you can see it clear its throat and never does it again, even on a cold start the next day or whenever.

I just took it out the garage today for a fiddle and put it back in when it started to rain, I can guarantee it'll be a bit smoky when I start it again. I usually make an excuse to take it out if I start it, not running it up to temperature must contribute to carbon build up.

Classically, this means the oil stem seals. It's not the end of the world but it's likely they need a bit of heat to seal properly. Otherwise the oil leaks down the valve stem and sits on the back of the valve.
I did see a revised set that were considerably beefed up.

Also can smoke badly if the oil is overfilled as it' gets drawn into the intake.

[adsgreen]

What will happen if you don't do the carbon cleanup? Would the engine pack up around 100k miles?

The pictures look a real mess! Is this the entire Audi fsi range?

Shouldn't Audi spend a bit more on R&D to come up with a fix?

Has anyone approached Audi UK directly on this issue?

~

The engine won't pack up - the engine will just gradually go down on power/efficiency to a point that it will go into limp mode.
If your car has 100K on the clock and has never had a carbon clean I would strongly recommend that you get it done - the difference it makes is like night versus day - The usual suspects, MRC, AMD, Unit 20 & Revolution all offer a service to get it done in a day - around £500 - I consider it to be an annual service task

There is no fix for it - it's a design flaw with the FSI engines as there is no actual fuel flowing over the valves - It just seems to be that the 4.2 V8 suffers more from it

Not sure I agree with this. Based on the research and reading of the problem over the years, it's very common for a "significant" amount of coke to return within 1k miles.
Based on that if the problem wasn't self limiting then all engines would be dead within 20-30k miles but that's simply not the case.
I was says the crud builds up to a point then it isn't strong enough to cope with the airflow into the engine and small bits break up and are burnt off. it also explains why being a little hard on the engine with occasional full power runs does in fact reduce the problem if not eliminate it.
You can see this if you dyno a car that's been city driving a lot as you actually see sparks coming out of the exhaust as the revs build.

[sync24]

[Not sure I agree with this. Based on the research and reading of the problem over the years, it's very common for a "significant" amount of coke to return within 1k miles.
Based on that if the problem wasn't self limiting then all engines would be dead within 20-30k miles but that's simply not the case.
I was says the crud builds up to a point then it isn't strong enough to cope with the airflow into the engine and small bits break up and are burnt off. it also explains why being a little hard on the engine with occasional full power runs does in fact reduce the problem if not eliminate it.
You can see this if you dyno a car that's been city driving a lot as you actually see sparks coming out of the exhaust as the revs build.

Fair comment and very true. I just see it as preventative maintenance but I am not going to go out my way to get mine done again this year. It's just one of those niggles that forms part of owning an RS4

[adsgreen]

Yeah I agree