superangrypenguin

I sold my B7 A4 many years ago and bought a W204 before they went DI in the C300 in 2012. After catching myself up on this board, it appears that MB also suffered the issue of carbon buildup on the intake valves. I spent too much of my life dealing with UOA's and learning about DI that I have been very happy not having to deal with the woes of DI.

I'm looking at potential replacement vehicles and the 2016/17 E300 is on my list. Has MB solved the DI issue in the latest gen? Is there port and direct injection now like Toyota/Lexus? Or has water injection been used like the M4?

Thanks!

LILBENZ230

Mercedes doesn't use direct and port injection like Toyota and I have never read anything about water injection, but I also don't see many problems reported either. The M276 has been in lots of Benz cars since 2012 and I haven't read about issues with it. That's if you went 2016. I don't know about the new 2.0.

c4004matic

Not to worry the DI issue was more of an urban myth than a real problem and only in the first gen DI engines. We are in at least gen 3.

c4004matic

First thing, there isnt such a thing as port direct injection, it was port fuel injection. All direct injection systems are exactly that direct injection into the cylinder, just as in diesel engines. The technology is old hat now, no worries. You can always tell if an engine is DI by simply lifting the hood since all DI systems up to now tic all the time just like diesels do.

joshg1001

The OP was referring to the 3.5 V6 in Lexus models that have both port fuel injection, and direct injection, and switches between the two depending on what is needed for optimum performance.

LILBENZ230

Carbon build-up was not an "urban myth" (whatever that means). VW/Audi was plagued by issues, Mazda had some issues, even our old 09 135i had to be shell blasted at 39,000 miles due to carbon buildup. It's a valid concern.

Zavato

Use top tier gas

c4004matic

Ive had DI vehicle 2 from Honda one from MB, I never had any issues, it was a minor problem of some manufaturers. Its been solved for a while now. I guess another reason not to buy bimmers lol!

c4004matic

Yes.

LILBENZ230

The use of 100% top tier gas did not save the BMW from carbon build-up.. Gas does not touch the intake valves. To say, basically, that it is not an issue because you've had 3 DI engines without issue is anecdotal. It was more than a minor problem in the past, and obviously a concern for Toyota and that is why their 3.5L V6 engines had both port and direct injection from the start.

I am not saying that MB has a DI problem, or that any particular new car will. But I do understand the concern based off of past experiences for people across several makes.

superangrypenguin

The comments about using top tier gas are asinine and quite frankly it reflects a poor understanding of how DI works. It helps (the fuel additives survive combustion for top tier gas so that may help clean intake valves (blowby) but it is not the solution)

Have there been pics taken of MB DI engines' intake valves? Without this, it's hard to say that the issue has been resolved. Most people can't tell if their engines have decreased HP after a few years due to DI and the carboning (is that a word?) of intake valves.

Has the reduction in flashpoint in oil due to DI stopped? Have people been posting UOA's of engine oils for MB DI engines?

Without solid information, we cannot say that the issue has been resolved.

c4004matic

Simple, dont buy one!
Just one problem, virtually every new engine in the market is DI. As explained there are 10 of millions of DI cars on the road, the overwhelming majority without issue, many, for over a decade or more.

LILBENZ230

This was my point. The BMW dealer initially tried saying that shell blasting to remove carbon build-up in our N54 would NOT be covered under warranty. When I asked why it would not be covered, I was told by the SA that it was because they suspected I had not been using Top Tier gasoline. I informed the SA that either he truly didn't understand the mechanics of DI or he was trying to pull a fast one. It ended up being that he didn't understand that gas did not touch the intake valves, and I gave him a bank statement showing fill ups exclusively at Chevron and they covered it.

The BMW was hesitating a bit during acceleration with slightly choppy power delivery. My C350 now has similar mileage and no issues.

superangrypenguin

That was a very helpful post.


The whole point of this thread is to see whether or not there have been a fix for the DI issue by MB.


It appears not. There are still plenty of other options (Subaru, as an example). Or my next vehicle is a Lexus.

LILBENZ230

FWIW, part of the maintenance plan on DI BMWs is to scope the engine. It was part of every oil service. I don't see anything about this on the Mercedes cars.

superangrypenguin

Wow. Does that mean an oil change is an insane amount with BMW?

LILBENZ230

That I can't tell you. I got rid of the car at 49k miles, so up to then all services were covered under the maintenance plan at no cost to me. Even got front and rear pads/rotors at like 46k.

superangrypenguin

I find this DI nonsense so sad. These are beautiful cars. I love the new E class!

This means i'll probably wait until the Bluetec comes out.

Merry Christmas Eve everyone. Thanks for the help!

c4004matic

MB invented DI in the 1950s. They have never been mentioned in the vw bmw issue. Furthermore even in those brands the issue was only rare in their fist gen DI it has dosappeared after2010 models. Much ado anout nothing.. Do a search all you ever wanted to know about this defect is all around the net.

dieseldoc

Both my current Mercedes have DI. No issues so far.

superangrypenguin

Mileage and year of vehicles, if I may ask?

dieseldoc

2014 c class 16,000 miles
2016 GLC 4500 miles

superangrypenguin

Thank you for sharing.

My A4 issues didn't really enter my life until the 50,000 mile mark. That's the main issue I have with DI engines. I have decided to keep my vehicles for quite a few years, and that's when DI engines start to putter (no pun intended).

That's also when owners started to report issues in the B7 A4s. The RS4s presented issues at around the 12,000 mile mark unfortunately, but the regular A/S4's worked quite well, until the 4 year 50k mark

Hence why I started this thread.

RJC

I believe MB uses two sets of injectors per cylinder in their DI engines so carbon build up is not an issue. If there's only one DI fuel injector it does not allow for the fuel to spray on the valves and they will not be cleaned with the detergents contained in the gasoline so major build up after say 40k miles will be present. Audi and others that have the DI carbon build up issue have not adopted this and use just one.

LILBENZ230

I've never heard this.. Toyota is the only one I've heard using port and direct injection.

Any links or documents you can point us to?