Jack, from my understanding with talking to the local dealer and the head tech at the dealer (Bert Smith) is that whitish/grey inside the tips is a perfect burn. I am gettings this at the track. Also I shift the PDK on the street in manual mode and am keeping the rev's above 2500rpm and notice less soot so this plus 8k miles and 12 DE's I think the engine is breaking in finally. The Porsche factory techs are very aware of the soot issue and some Porsche factory techs were at the dealer not to long ago and where asked about the soot/oil issue. I was told that Porsche is aware of it and just smiled and claims nothing is wrong....so...who knows?

 

I wonder if they run the mixture rich in the low rpms to keep things cooler in the combustion chamber? I wonder if we could find some of the guys who have their ECU reprogrammed and see if they get soot too.
It is my understanding that the software leans things out to get some HP...shouldn't that reduce soot????
When I asked my dealer about soot and fouling catalytic converters in an email...for some reason they would not reply. They would only verbally reply and gave a typical "non-answer"!

 

Is regular injector service being offered or rec'd by dealers ??

Jack

 

I am sure that if they are making a dime on 'injector servicing", then they will be recommending it!!! LOL.
Either way, the carbon buildup is not localized to the injectors, but rather the intake valve. I think the 'sooting' is due to the mixtures they run on ecu. I think the best defense against buildup is to run tier 1 gas and to get your car to redline with regular frequency!

 

The issue is that fuel is not going over the valves to clean them. So they get fouled. Noack oil testing is important because the lower the viscosity engine oil. The more evaporation of the oil will foul the valves. So i would consider a 5 w 30 or 10 w 30 oil and add a catch can that is baffled to help catch the crud.

The noack number of evaporation should be less that 7 to start with. So find that oil test number if you can. Changing oil is very cheap insurance. Dfi is going to cause problems in most every engine design. So get used to understanding the problem, how to avoid it as much as possible , and how to best solve it.

 

reviving a 10yo thread. Nice.