Removal of Carbon Deposits

[Critter7r]

The stuff that builds up on the current direct injection valves (at least in the BMWs) is a goopy, semi -solid tar-looking substance about the consistancy of dum-dum. i'm pretty sure that it's just solidified oil. And if the car is regularly driven for a long enough time, the oil vapors and the valve get hot enough to keep the goop from gathering on the valve. But once it gets started, it probably collects exponentially.

[BimmerBreaker]

The problem comes from a layer of the oil contacting the hot valve that gets burnt and caked on and then will not simply come off. That is why it ends up building up instead of cleaning off everytime the engine reaches operating temperature.

[Critter7r]

The problem comes from a layer of the oil contacting the hot valve that gets burnt and caked on and then will not simply come off. That is why it ends up building up instead of cleaning off everytime the engine reaches operating temperature.

Hadn't thought of that. Which would negate my short-trip theory ....

So the problem is that these stupid vapors are even re-routed back to the intake at all, regardless of whether the engine is regularly driven hot or cold.

[BimmerBreaker]

So the problem is that these stupid vapors are even re-routed back to the intake at all, regardless of whether the engine is regularly driven hot or cold.

Precisely. Which is why a CCV delete is really what we need more than anything else to prevent this from ever becoming a problem in the first place.

[ross1]

This is the only way to clean a N54. You can add all the fuel system cleaner you want, but since it's a direct injected motor it won't clean anything before the cylinder. The N54 has an issue with carbon buildup on the intake valve and the runner right before the valve.

True
This is a problem on all direct injection engines

[Rudolph320i]

True
This is a problem on all direct injection engines

Yea, when I first heard it I did some looking into it and its definitely an issue. When I was working at a Hyundai dealer the DI engines had carbon buildup issues.

[Kevlar]

Lexus solve she problem by running two sets of injectors.

Audi/Porsche had this problem years ago. I'm honestly surprised there is not a better solution to this problem yet.

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[timsev]

High revving NA engines is the solution.....

[HoJo]

High revving NA engines is the solution.....

High revving N/A direct injected engine will have the same issue. The turbo isn't the cause.

[timsev]

I never said anything about DI or turbos.

[ptarditi]

I never said anything about DI or turbos.

NA = Naturally Aspirated hence non-turbo.