Cleaning our direct injection GTI’s intake with walnut blasting

I DIY'd this on my 2009 MINI at 50K miles, as it was recommended by the dealer......mine were gunked up but it didn't seem to bother it - no rough idle or codes popped up.

I just pulled the intake again at 112K and - clean as a pin! Guess I'll check it again at 160K. It sure needed it at 50K tho......

The walnut shells did a great job, cleaned it up and looked like new when done.

I'd like to have this done to the Expedition. It has a rough idle when cold. Not brave enough to DIY it, and I can't find anyone local that does it.

Do NOT blast an intake manifold with aluminum oxide material - especially on a turbo engine. Your rings won't outlast your oil change.

In reply to Tom_Spangler (Forum Supporter) :

I would start with throttle body cleaning first. Cheaper and easier to rule out first

So sweet of the local squirrels to do that for me under the hood of my BMW 

I'm going to fix mine with some wet nitrous...

I think understand the root cause of the problem, but why don't we hear about this for direct injection diesels?

I'm hoping I can put this off until I have everything I need for an MPI retrofit on my Alltrack. It'd be nice to only have to do this once over the life of the car.

Anyone know how much of a difference having dual injection makes? I have an RS3 which I believe does both direct and port injection. Port injection is supposed to help keep the valves cleaner. I'm not sure what extent though.

I've also heard that running your car hard and getting it hot helps prevent or break down carbon build up, but that definitely seems false now, haha.

In reply to xeonoex :

PF-DI should not have the same problem- back in the 80's and 90's, intake system deposits were still a problem, but everyone pleaded with the EPA to force fuel suppliers to have a strong minimum of detergents in them.