dfordham

Good article in layman's terms about DI and its potential problems.

http://www.thetruthaboutcars.com/201...l/#more-442513

Regards,
Don

SoCalCLK

Interesting article. Thanks for posting this.

BenzV12

Thanks for the link
It's also advised that you should periodically clean inhectors , it was not until I read this topic that unburned hyrocarbons were mainly responsible for carbon builtup

SoCalCLK

Good idea. What kind of fuel injector cleaner do you use? Or do you have the dealership do it? I've heard good things about Chevron Synthetic FI Cleaner as well as Redline.

BenzV12

Once I bought Sonax in auto markets , I honestly didn't spot any major difference.
Then I have the dealersip do it and they do use a special machine , rev up the engine at high revs for minimum 15 minutes I suppose .

The mechanics whom I talked to in the private shops recommend Carbon Clean for diesel engines .

K-A

Still not convinced about the long term prospects of D/I, and not convinced that it's a rather simple way for Automakers to squeeze out some extra HP and MPG to sell their cars. I've seen some disturbing photo's of carbon build up on newer cars, and I've heard that the motors may even lose HP in due time, especially if they aren't maintained and cleaned to a "T". Aside from that, they sound terrible at idle from outside, with that Diesel-like tapping sound.

.... Of course, they perform efficiently and better than non D/I motors (comparatively) from the get-go, and we don't know their true long term lasting values yet, for better or worse.

Wig

To be fair, direct injection engines have been around in Europe for many years. Audi had them at least as long ago as 2005, and used them in North America. It must be known how direct injection performs over the life of an engine by now. Let's hope Benz gets it right.

RNBRAD

My brother has an 09 model 335i with DI. It's been in the shop three times for injector issues and carbon deposits on the exhaust tips. Not sure if this is DI issues or not but it's been giving him a lot of trouble.

sharpxia

Oh, no, I just got 2012 E550 with DI.

hyperion667

so...use premium, and cahnage fuel filters more?

MCF

Our gas is simply too dirty for DI engines to be considered for 100K mile usage. Sell before warranty runs out.

ImInPA

Huh? Pure BS. While it is trule our fuel is not as "clean" as the European requirements, the fule systems in our cars are compensated for this. There is no known, factual reason that a DI engine can not achieve at least 500K miles. Diesels with DI have been beating this figure for more than two decades, while burning a fuel considerably dirtier than gasoline. This is just uban legend hype that gets past on to the truly unknowledgable and paranoid. Just my two cents.

dfordham

https://mbworld.org/forums/c-class-w...n-buildup.html

This thread on the W204 forum has some photographic evidence of known problems with some DI engines. The thread gets a little personal in places but does thoroughly cover the subject.

Regards,
Don

Raymond Lee

ImInPA
1+. I agree with you 100% and some!

alloutmk23

So all you guys with the 10s and 11s wouldn't trade your engine for a 12 DI? Because i would in a heartbeat, I wish i had that extra HP (for the V6).

No reason to rag on DI engines or find excuses on why our model engines are better..Just saying.

dfordham

I, too, would take the new engine in a heartbeat but I only keep my cars 2-3 years and don't put a great many miles on them.

Anyone who keeps their cars long term must take into account the potential problems of DI. MB has not given any detail on how they have addressed known problems from other manufacturers. I trust MB engineering, but as Ronald Reagan said: "Trust but verify. "

Regards,
Don

Kar don

This thread is hilarious. DI engines have been around for a while... in diesel even longer! Lexus/Toyota has a port/DI system in their motors and it seems to have the best of both worlds.

GoBlando

This is a problem that doesn't exist on the diesels because it is a different type of fuel. I just came out of a 2008 Audi S5. I put 70k on that car. I had the check engine light come on multiple times due to misfires on 5 or more cylinders. At 55k, a couple chunks of the carbon broke off, and wrecked the catalytic converters. The problem has to do with oil making it through the EGR. After a full cleaning the car ran fine, but I had misfires about 5k miles later.

For the S5, I discovered that almost none of my local gas stations were on the top tier gas list. The Mercedes manual explicitly says to make sure you use gas from these stations. It makes a big difference as it helps to keep things clear in the first place.

The list is here: http://www.toptiergas.com/retailers.html

theraven333

Want a cleaner that really works on injectors BG44k for either petrol or diesel engines. Is not cheap and used every 15-20K keeps the top of the engine and fuel delivery system very clean.
Compared to other things on the market redex or equivalent which are 2/5ths of useless, this stuff really works.
In fact some top end marques Bentley, Lexus etc use it as part of their service.
If you have never used any cleaners and your car has reached say 50k, then the carbon build up will be difficult to clean unless you use one of these special injector systems where they hook up your car and run for about an a hour to clean the whole internals!!!

petee1997

I think the problem mentioned in the article was the alcohol in the gas. Diesel does not have alcohol which may explain the longevity. I have read about this before on the Porsche site. In Canada Shell 91 octane gas does not have alcohol (ethanol) and may be an alternative. I am not sure if the US has gas without ethanol?

My wife had a 2007 BMW 335i that had fuel pump issues. I am not sure what caused the problem at the time but it was a common problem on those first DFI TT engines.

However, once you drive these new DFI engines, there is no going back to port injection especially the turbos with high torque.