We have boroscoped a number of customer cars at my Benz dealership out of interest at various mileages and so far things look fine even with high miler B Classes. We had long discussions about this on the W204 forum when the M276 DI V6 engine was first launched & not a single problem reported. Benz & Ford seem to have the potential issue totally covered without the VW/Audi band aid. Benz has built DI Diesel engines for so long that they really know what they are doing.



Edit: & yes, fouled inlet valves have a marked effect on performance. It can get a lot worse than my Porsche picture. That was a low miler



Audi intake.




General.

 

It is common knowledge that DI engines increases the potential for Carbon Buildup. Like I said all manufacturers are dealing with this problem with cars that were built since DI cars have come on the market. If you think that Audi and VAG is the only ones with this problem then don't take my word for it but visit various manufacturer forums and read for yourself. You can also google if you like. It is also a fact that with the increased carbon buildup increases fouling of the engine oil with fuel which will cause higher consumption.
Newer designs have various solutions to lessen this possibility but those engines are just hitting the market.
Also just because you don't see the problem in South Africa doesn't mean the problem doesn't exist. One of the main factors besides design is the way one drives the car or location. You being in South Africa you don't deal with cold weather. DI engines need to be driven hard to increase engine temps which reduces the carbon build up because it provides a cleaner burn. Customers that live in cooler weather climates are much more susceptible to carbon buildup because in the winter months the engines may not be able to warm up to operating temps between work and home.
Just because you don't run into these problems in South Africa doesn't mean the problem doesn't exist.

Don't take my word for it but if you want to argue with a mechanical engineer with a MASc who has worked on Formula SAE then you go right ahead.

Here is the link http://www.thetruthaboutcars.com/201...in-a-nutshell/

 

I know all that. I've shown examples above. It's not an issue with Benz or Ford. They have managed the issue from grass routes design. The carbon does not get into the oil. It comes mainly from the oil/oil vapour & poor fuel in some areas of the world. It has no contact with the oil. It gets blown out of the exhaust which is why he correctly states that it could damage turbo charger vanes or cat converters if it comes off the inlet valves in big chunks. It does not increase oil consumption. It does not increase oil fouling/contamination. I've just retired from a global oil company job in which I had frequent contact with Benz & all OEM's. See my profile. My experience is not only South African. I was a long-term member of SAE until recently. This thread is about Benz cars & oil consumption. The only area where he & I might disagree marginally is that he ascribes most of the deposit to captive breathers. In our experience (& we have some of the largest research labs dotted around the world) that is the minor contributor with the major contributor being lack of oil control down the valve guides & VI Improver burn on to the valve tulip. The ratio would vary from one engine design to another.

The article does not disagree with anything I've said. I did not say the problem was confined to VW/Audi (VAG) Group & Porsche. I merely used them as an example & because I had pics of their problem & fix.

 

I am not saying the carbon build up gets into the oil. What I am saying is that the carbon build up causes inefficiency which means unburned fuel which gets into the oil. This fouling of the oil causes some of the complaints of excessive oil consumption.
What I am saying is that Direct Injection engines are a lot more susceptible to oil consumption due various factors such as poor fuel, engine operating temp, carbon buildup, design than port fuel injection cars of the past.
Heck in some places MB had problems with carbon build up with engines in the W203 cars which I believe where not DI.

 

Our 2015 C300 now has app. 3500 miles on it and the dip shows the oil at exactly the full mark. Just where it was when we bought it. I too asked the SA at the dealership about an early first oil change. He said absolutely not. One year, 10,000 miles or when the Assyst said to do it.

 

You don't suffer unburned fuel & it does not get into the oil on a Benz. Even running open loop fully enriched at cold start they don't get fuel into the sump oil ~ it goes out the exhaust & all these engines run excess air blowers, go into high idle & hold gears for longer under warm up to heat the cats quickly for emissions purposes. They do build a little bit of water in the oil which evapourates off on a hot run. We have done 1000's of samples of used oil from DI Benzes around the world & zero fuel dilution of the oil. You are wrong & explain yourself poorly. The minute operating temp is reached which happens very quickly with Benz new 4 Way electronic thermostat you switch to closed loop & the lambda (O2) sensors will adjust the fueling rate back to suit incoming air. If the inlet valves are fouled enough to compromise airflow the fueling rate is cut back to suit for correct AF ratio.

The W203 M271 head fouling problem was due to head design for Euro 4 & 5 fuels at that time. On crap fuel they fouled & were redesigned from approx March 2004 production for less desirable fuels. Benz only sold W203 CGI cars in Europe that were DI as they required min Euro 4 fuel. ROW was port injection.

I remind you that you stated ~ "GDI engines will consume more oil because they are more prone to carbon buildup of the valves which in return will cause more fouling of the oil and hence more engine oil will be consumed"

Also note that the article you posted makes no mention of fuel dilution of crankcase oil. That will be because they have never found any. Also note that the first indication of fuel dilution is a rising of crankcase oil level. e.g caused by a badly damaged dribbling injector. This is however more prevalent in diesel engines.

 

Your experience is normal & you have been correctly advised.

 

I guess we can agree to disagree and only time will tell if the current engines will be consuming more oil and if Carbon buildup will happen.
I do hope with second generation DI engines from various manufacturers will fix this problem.

 

Both the TurboV6 & the inline 4 are second generation for Benz. Both replace previous DI engines.