[fun2drive]

DI engines get carbon from oil fumes sucked into the intake from a PCV system under both vacuum and boost. Rob has a boost PCV replacement that doesn't leak as much as the OEM but doesn't help at all under vacuum.

I have read a few owners with high mileage that switches oil from the factory BMW Castrol 5W30 to other high flash point oils and have never had the problem return. The one owner who had 180K miles on his had the turbos replaced, HPFP and walnut blasting around 50K on a well modded car. He has reported the problem has never returned.

Almost impossible to tell if higher flash point oil make the difference, other oil made the difference since no one had documented that as far as I know except posting here. Clearly there is some solution out there that we will eventually all discover but right now who knows. I read a lot about the GM DI and from what I could tell the airflow pattern was different and GM engineering was stating that it would reduce DI carbon build up by more of a swirl pattern. If I can find that article I will post the reference.

I have a borescope and 57K miles on my 335. At 70K miles I will see what my intake valves look like and do the walnut blasting if required but I would change to any oil if I knew it would eliminate or reduce carbon build up...

[freshwater]

I saw this article for DI.

http://www.edmunds.com/autoobserver-...-adopters.html

[galahad05]

That was a pretty informative and interesting article, fresh.

[BashShah]

Very interesting Read.
So, the walnut blast has increased my miles per gallon.
100% noticable.
I was at 13.5-13.9l/100km.
Now, last week, 12.1
This week 12.2

I reset it every fill-up.

So, if I have to spend every 45 to 50k-km.
I can live with it. For me that is every 3.5 years.

DN

[CaptChaos]

Originally Posted by DarkNemesis

Very interesting Read.
So, the walnut blast has increased my miles per gallon.
100% noticable.
I was at 13.5-13.9l/100km.
Now, last week, 12.1
This week 12.2

I reset it every fill-up.

So, if I have to spend every 45 to 50k-km.
I can live with it. For me that is every 3.5 years.

DN

Where did you have it done and how much did it cost? I am coming up on 60k and am wondering if I should do the walnut blasting.

[freshwater]

Originally Posted by CaptChaos

Where did you have it done and how much did it cost? I am coming up on 60k and am wondering if I should do the walnut blasting.

OP paid 805 at the Dealer

[BMWNTHZST]

After having the Walnut blast done two weeks ago its like owning a new car again

[freshwater]

I be getting mine back in few days after Walnut blasting, 6 plugs already changed last august and adding COBB Tuning on top of that will make this Car on steriod..

[freshwater]

Ok Daytona 500 time, Start your Engines.. hope Dale Earnhardt Jr Wins this time his Father was a great Racer ...

[BMWNTHZST]

Originally Posted by freshwater

Ok Daytona 500 time, Start your Engines.. hope Dale Earnhardt Jr Wins this time his Father was a great Racer ...

I second that and here's hoping Danica finishes this race.

[BashShah]

Total bill was 825 including tax.
I am Vancouver, Bc, Canada.
1 hour diagnostic.
Which covered code scanning.
And bore scope to see how much carbon built up there was.

Then 4 hours labor charge for the blasting.

My advise, tell dealer, just do the blasting, without diagnostic fee.

Save yourself a bit.

DN

[freshwater]

Pics of Valves Before Walnut Blasting. looking pretty bad.
dont have After pics.

[Blubaron79]

Originally Posted by freshwater

Pics of Valves Before Walnut Blasting. looking pretty bad.
dont have After pics.

The dealer showed me pictures of mine before the blast; and believe it or not it was even worse than those pictures..

[freshwater]

If you take into account I got 99k+ then they are not as bad as I had seen others on this board.. Will see tomorrow how it runs.. I am expecting much better performance at higher RPM...

[Game]

Originally Posted by Evan70

I just had mine blasted at 45K miles. Car is stock, and has always had dealer service. While not horrible, there was significant buildup.

Originally Posted by freshwater

I read about DI, Carbon buildup, Misfiring, hesitation on higher RPM and seems like the issue is worst for DI Engines build by BMW/VW/Audi/MB, GM and Toyota not having that much problem not sure about volvo..

Mine 335i 97k on it start having issues around 85k with Misfiring and codes thrown, Still a CPO car took to Dealer cause was Spark plugs, they change all 6 and Car was fine. now around 92K i start seeing slight hesitation on higher gears and RPM, problem got worst every 1k I put on the car. Took it again and they finally figure out its the Famous Carbon build up on the Intake Valves, Remedy was Walnut Blasting, so Car still in garage for that procedure to be completed. Hopefully it will be 95% better.

So now come to the cause why this happening to the DI engines Design by the Brightest Auto Engineering minds in the entire Universe..

1) Cant be the Fuel since Fuel never touches the Intake Valves and adding BG44 or TEchron will not Help much may be help with Fuel injectors..

2) How about the Synthetic Oil we used, I had read that 1 person change the Oil from Mobil 1 SAE 0W-40 to Castrol Syntec European Formula SAE 0W-30. And never saw any Carbon build up on the intake valves after driving for many many miles..So is the Oil causing it and we should start using the correct oil. and what is the correct Oil to use. ???

We cant afford to keep getting Walnut Blasting every 25k from these State of the Art Engineering Machines..

My Indi shop used, Motul Full Synthetic 0w-30, Lubro Moly 0W-30 or FUCHS 5w-30, and after 50k I been using this every 10k miles. Before that it was BMW Dealer Oil. not sure what he was using.
My Mileage from the Display which i never reset is 25.2mpg so that from almost 50k miles of driving, 60% Hwy and 40% City.


Normally people using these Oils:
--------------------------------
Castrol Syntec European Formula SAE 0W-30
Mobil 1 SAE 0W-40
Pennzoil Platinum European Formula Ultra SAE 5W-30
Valvoline SynPower SAE 5W-30
Motul FULL Synthetic
Lubro Moly 0W 30
FUCHS 5W 30


Link to Liqui Moly which is same as Lubri Moly.

http://forums.vwvortex.com/showthrea...Moly-Oil-Forum

Nice article about Moly, it did mention it helps in reducing Carbon. "Moly reducing friction which reduces heat, this helps keep rings free from carbon buildup, prevents blow-by, decreases emission, and extends oil life." " By filling in the craters and pores Moly improves this seal allowing for more efficient combustion and engine performance."

http://www.bobistheoilguy.com/moly-basics/




Another additive they been using is ceratic see below to increase Engine Life.


CERA TEC
Motor oil additive
With high-tech ceramic anti-wear protection

How does CERA TEC work?
The graphite-like structure of the ceramic particles enables them to fill in the roughness present in the metal, thereby preventing direct metal-on-metal contact. An active chemical (friction modifier) utilizes the existing friction energy to ensure flowing i.e. non-abrasive – smoothing, annealing the friction and bearing points.

CERA TEC is a suspension based on a microceramic solid lubricant and chemical active agents in mineral oil. This combination reduces friction and protects the engine and transmission against wear. This in turn prevents expensive repairs and prolongs the life of the assemblies.

CERA TEC offers high mechanical and thermal stability, ensuring outstanding lubrication even under the toughest conditions. Engine and transmission noise are reduced.
It saves energy, reduces fuel consumption and thus also pollutant emissions.

CERA TEC reacts directly with the surface of the metal and protects your engine for up to 50,000 kilometers - even with the oil being changed during that period.

Did your warranty cover the walnut blasting? Or was it out of pocket?

[freshwater]

Originally Posted by Game

Did your warranty cover the walnut blasting? Or was it out of pocket?

Covered under CPO. My out of pocket is $50 total.
They even change 2 Coils and Gaskets on the Intake.

[Game]

Originally Posted by freshwater

Covered under CPO. My out of pocket is $50 total.
They even change 2 Coils and Gaskets on the Intake.

Thanks.

The only hesitation and jerking I've gotten was occasionally after putting it into first gear. I really want this done though before my warranty expires in a couple of months. Any advice on what to tell the dealer?


edit - Just saw you're from Illinois. Which dealer did the work?

[freshwater]

Game,

Mine is done at Bill Jacob Naperville, so far they are very reasonable in doing all the CPO work on my both BMWs.

Dealer wont do anything just because you tell him to do, they look at codes thrown and if you seeing any issues, then they will go after the problem since they need Evidence to prove to BMWNA that they record the issue and its under Warranty.
Try to do some spirited driving hitting higher RPM, if any issues with Coils or Injectors or Intake valve then you will see hesitation at higher RPM and if you lucky they will throw some codes too, thats what mine did.then just drive to Dealer with that Evidence, thats all they need. If its spark plugs then they not covered under CPO all other stuff is covered.

[freshwater]

Also ask your Dealer to look for any leaks if they can spot them, that's all covered too.

[Game]

Originally Posted by freshwater

Game,

Mine is done at Bill Jacob Naperville, so far they are very reasonable in doing all the CPO work on my both BMWs.

Dealer wont do anything just because you tell him to do, they look at codes thrown and if you seeing any issues, then they will go after the problem since they need Evidence to prove to BMWNA that they record the issue and its under Warranty.
Try to do some spirited driving hitting higher RPM, if any issues with Coils or Injectors or Intake valve then you will see hesitation at higher RPM and if you lucky they will throw some codes too, thats what mine did.then just drive to Dealer with that Evidence, thats all they need. If its spark plugs then they not covered under CPO all other stuff is covered.

Originally Posted by freshwater

Also ask your Dealer to look for any leaks if they can spot them, that's all covered too.

Thanks for all the info.

I might as well drive it hard for the last couple of months of my CPO right?

I also actually have a friend that's one of the head mechanics at the Naperville dealer, I'll ask him for his opinion too.

[galahad05]

Well, here is a before and after--my SA only sent me the one pair of pics (presumably the worst before: bet it's cylinder #2).

[galahad05]

That was on a motor with 65k miles.