has anyone considered, or has done, walnut blasting the valves on the DFI engines? My 09 isn't showing any signs of sluggishness but it could be that I've owned the truck for 13 years now and I haven't felt it the way it was since I got it. I've heavily considered it but I haven't seen anyone else who has done this with there trucks.


anyone have a experience with this??

 

It is popular with a lot of direct injection vehicles. Same principles would apply, I think I’ve seen someone on this forum do it.

 

Yes, I walnut blasted my GTS a few months ago after getting my pig.

Are you planning to DIY, or take it to a shop? If you’ll DIY, I can share some guidance.

What tools do you have for the job?

It was a bit of a pain to get to the rear cylinders, and the fine walnut media I used wasn’t able to break up all the heaviest clumps of carbon. So, I got in there with some brake cleaner and a good set of picks and screw drivers.

Certainly not at easy job, but it made a BIG difference. There’s now a very noticeable spike in torque over 4K RPM. Fuel economy also increased, and it just feels more eager.

I now consider this to be a critical maintaincw item for high mileage DI pigs. I plan to clean mine every 2 years.

 

Leave it alone till perhaps the starter goes **** up

 

Definitely on my list. But not urgent. Anyone have a good source for an adapter to shove in the hole?

I feel like we should have a forum shared blasting kit and DIY ha ha. Anyone care to go halfsies? Bonus if you are in SLC…

Service guy said they charged $50/cylinder, plus the labor to get in and out, so roughly $1K for the job.

I’ll likely DIY.



Mine all look roughly like this at ~85K on an ‘09 CTTS with unknown service and care history.

 

https://www.6speedonline.com/forums/...ng-bank-2.html

 

Wow, that's pretty chunky. Catch cans and better oils should be able to help prevent some of this and extend the cleaning interval.

 

https://rennlist.com/forums/cayenne-...edition-3.html

 

I'll be doing this over Christmas shutdown. The intake has been off for a couple of weeks now to replace the starter. Looking at the valves, if Crozzer's are chunky, mine is blocked and in cardiac arrest. Now, this is the worst one. The best one doesn't show the moonscape on the valve. I'm leaning towards buying the Autool all in one unit, simply because it has the pistol grip and finger trigger gun. Seems more controllable. Not sure yet. If I do get it, I'd be willing to ship it off to others that might wish to use it.


A data point in response to the comment about quality oil, this engine has 160k miles and until last year was serviced yearly at the dealer with Mobil1 oil. Not sure what to make of that. In this case, it is likely just the quantity of oil laden air that has moved through the engine.

The strategy of keeping this clean, or how often to clean seems a bit murky. There are quite a few variables that will change how quickly this accumulates. Any data on catch cans with 100K on them? Efficacy of the solvent cleaning method? I can't see it working in my case, but might work with only a thin layer of carbon. Checking every 20K would mean I'm looking at it every 4 years. That's doable.

 

Mobil 1 is not good oil. I'm sure Porsche is paid a fortune to make it their factory fill and recommended lubricant, but it doesn't do well in UOA comparisons against oils.like Motul, Driven, and Liqui-Moly.

 

My common sense radar says bad idea to run sludge through the engine… does anyone care to comment on real experience or results using the CRC or similar solvent to shoot through the throttle body of a running engine?

 

All V8 Cayennes 07+ have the DFI
This is what a oil catch can is good for, and also to keep oil vapor from going into Turbo on CTT

I just did a Jetta and have done BMWs before. Harbor Freight for Walnut material, and <$20 on Amazon for the blaster. Just use a bucket no need to get fancy.

Id probably recommend Medium grit the fine took forever on Jetta. Try to clean as much out as possible with scrapers/screwdrivers first.

Happy to help design a 3D printable vacuum adapter if someone has some measurements of the intake hole and photos of around it.

 

08-10 model years are the DFI 957s here in the US.

 

Pete is the Oil Guy, I missed your comment on this: https://rennlist.com/forums/cayenne-...l#post18512426
Would other M1 folks expect to see the same build up as golock?
Which is the recommended Liqui-Moly ...the Leichtlauf?

Attached is mine (boosted the brightness of the ports in Photoshop), dont have a better image, from starter replacement several months ago
I did wipe the crude off of the walls and hoover before reassembling
The first two thirds of its 80000 mile life, girlfriends car, it was on P car dealer only service ...and then onto the Belgium Castrol

 

@phatz , you have the port injection engine which does not have the problem. Here is the direct injection engine. I'm jealous of how clean your engine is. I expect it is due to the environment. My engine spent it's first 13 years in New York by Lake Erie