spyked

As everyone knows, there is a big thread about the concern of DI and the new MB engines and how it relates to carbon build up (similar to VW/Audi, BMW, Mazda, etc.). The consensus appears to be that we will just have to wait and see. Too early to tell if owners are noticing any issues. No definitive answers have been received from MB about what, if anything, they have done to remedy possible DI related issues.

**Here's the thing, for M271 engines, it appears that one of them WITH CGI (DI) has been in use since 2003. The DE18ML. And the M271 Evo (that I have) has been in service with CGI since 2009.

So....has the international community, where the DE18ML and M271 Evo have been in service, complained or reported any DI/carbon build up related issues?

Here is the link to info I got http://en.wikipedia.org/wiki/Mercedes-Benz_M271_engine

Does that info make people more at ease? I see it as, maybe they never had any problems. We would surely have heard of them by now, 10 years later. Or, since the DE18ML was in service from 2003-2005 only, perhaps they improved the DI when they put the Evo version in service in 2009.

alsyli

No, not at all. The problem is that the US has relatively poor quality gas, and poor quality gas greatly contributes to the problem (I vaguely recall reading in one of the automags that this was why MB had delayed introducing DI here).... European gas is apparently of higher quality.

Knightmare69

Pretty much on point, the main cause of the carbon build up from what I've read on other forums using the same or similar tech is the low grade gas. However it is not the sole issue, even with cleaner higher octane gas, the design will still cause carbon build up, just a matter of how long before it affects the engine. Here in Hong Kong we get 98 octane so for us, we have a longer shelf life before we may experience this.

Utahkompressor

Interesting.

DCubed

98 Octane in the rest of the world is about 93 Octane here in the US, so people where 92 or 93 is available should have the same expectations as you but I believe it comes down to the purity as well as octane rating. Here in California we only get 91 on the pumps as premium so I generally only use Shell V-Power and if I am running low and there is no other alternative I will use Mobil with Chevron being last resort. My sisters Jetta with their 2.0T engine clogged up, but the source of their problem was the PCV system allowing oil to be re-sent into the intake.

kevink2

Just curious, are you sure MB doesn't do it too? For some other DI'd makes, it was the combination of poor quality gas (independent of octane level), and the combination of EGR and PVC streams being fed into the intake manifold.

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DCubed

Different designs, speaking with an old co worker who is a service director at a local VW store he is quite vocal about the poor design of the system in the MKV and MKVI Jetta/GTI with the 2.0T. The poor quality of gas will do it in over time but the combination of a bad PCV system and lower quality gas just was causing a lot of pre-mature failure. We got VW to goodwill it in the end (worked for VW dealers for 8 years before making the jump to M-B, used what little connections I had left to help my sister) but the fix without warranty was about $1100 and very few people try to push it and just pay the money or have them clear the code if they are willing and trade the car in shortly after.