FWIW Sean I will agree that you are right it is an oil based issue.
But it isn't just the oil. There are a whole load of other variables too.
The other 'crucial' issue is the cleanliness of the intake air. If you have a standard OEM pleated paper air filter, vs a non-standard non-paper filter, then there will be a noticeable amount more solid particles which will stick to any oil deposits. Just go and slap some suntan oil on, then get a breeze on a dry beach, and notice how all the sand sticks to you - exactly the same with this carbon issue. Then go and lie in a furnace for a few hours, and try getting the crusty sand and oil mix off you!
And the fuels. In the UK and western Europe, we have to have 'Ultra Low Sulfur Petrol', whereas in North America, their fuel is far less refined and 'pure' compared to ours. You only have to go to some of their rural gas stations - to be wondering what the heck is being pumped into your tank - and this also explains why the yanks have a 40k change interval for their fuel filters, yet here in Blighty and w.Europe, they are a 'lifetime' fit.
So, taking into account the yanks crap fuel, and that they have this amazing propensity to change absolutley everything on their cars - irrespective of weather it's good or bad - and which includes ditching the paper air filter. Now add that to the 502.00 non-fully synthetic oil - then it is hardly surprising they get probs. It is no different to how the yanks managed to fcuk up so many PD diesels, yet it was not an endemic prob here in UK or Germany. The sludge issue on the 1.8 20vT is the same - the yanks refused to take VWoA advice with fully synthetic oils, and thought they new better by using cheap mineral oil, but changing it every 3,000 miles - and wondered by conventional mineral oils had turned to coal in their turbo bearings. Again, not an endemic prob over here, because we generally follow the manufacturers recommendations.
However so long as we all stick to the VAG servicing regime it will happen.
Sorry, but I absolutely do not agree. Why do you think that VW AG and VW UK now insist that ONLY LL3 oils are used, even if the car is on T&D.
OK, I'm sure you all know my opinions on the LongLife 'regime' - and that it is no good for petrol engines, particularly petrols with a turbo - but the LL3 oil is superb.
The real issue is from using lesser spec oils, such as 502.00 oils - because these were never developed for FSI direct injection (and nor for TDI direct injection either). Whereas, the 504.00/507.00 LongLife 3 oil specification has a specific 'FSI' test sequence, and no other VW, or generic oil standard does.
But if you were to ask me 'is there a better oil than the LL3', or 'could the LL3 oil be further improved' - then my answer would be very likely. But as of this moment, the LL3 oil, from a quality European oil company, which only uses either Group 4 or Group 5 basestocks is the pinacle of what you can get. Don't forget, Volkswagen Germany work very closely with Castrol and Fuchs - two exceedingly highly regarded oil companies - both at the cutting edge of tribology, and there is only one other oil company who is in such high esteem, and that is Motul. So between the three of them, do you not think that they would have addressed the 'oil' issue if it were such a problem?
Until they can find an oil with the correct properties to stop this happening it s going to become a feature of these engines made worse by Direct Injection.
Sorry, don't agree again. Direct injection engines have been out for years. Just Google Mitsubishi GDI.
The only way to avoid it is to remove the oil from this system - Enter the Catch Can.
Nope, peeps have simply found a product, and are just looking for some reason to justify it.
But ETTO.