Possible Issue With DI (direct injection)
 

I found a post on another forum and found it interesting and also a little alarming. It seems that the Direct Injection can cause carbon deposits to build up over a semi short period of time on the intake valve. This can cause a loss of power. There are documented reports on the BMW, the Audi and the VW, so I would think that it happens on other DI engines. It appears that the assistant GM engineer for V6 engines is aware of the problem.

here is a link to the article, http://www.edmunds.com/autoobserver-...-adopters.html

I would hope that with GM being aware of this potential problem, and with over 6,000 CPU hours spent on the LT1 combustion chamber design they have addressed thsis

It should be fine since GM does not have a problem with buildup on the V6 engines. I would also assume that the LT1 doesn't have a problem because of its extensive combustion testing.

They all have issues with DI because the fuel never flows over the valves to clean them. This is why many people are using catch cans to keep the oil out of the intake and off the valves. I believe the LT1 is addressing the PCV problem but only time will tell.

in the MT interview, Tadge & the powertrain team were asked specifically about that. Their solution is an improved air/oil separation along with the better PCV. They claim that they haven't seen deposits on their engines yet and that the above measures will solve the problem.

I own a 2010 GTI and with 47,000 miles I can almost guarantee you my valves are gunked up but good. Dieseling noise is significantly louder and I'm down on power from being first chipped 2 years ago. Both are classic symptoms so I definitely have a vested interest in hoping they've solved the problem. VW/Audi has not to date.

Would it be safe to seafoam the intake with the car running on a DI motor?

All new technologies have their advantages and disadvantages. Carbon build up is an issue in all engines (even the current LS engines) but it is particularly bad in the new generation of DI engines because fuel never flows over the intake valves (or in some cases in a very limited amount). The key is to get an effective catch can in place as soon as possible. The good news is that since you are aware ahead of time you can be prepared.

On the contrary, the LLT and LFX actually do suffer greatly from carbon build up.

https://scontent-a-ord.xx.fbcdn.net/...98662108_n.jpg

My 1976 Chevy Nova 6-cyl Company Car required removal of head every 50K miles to de-carbon as part of the recommended maintenance.

It appears what is old is new again

Chase is correct. We have serious issues with carbon build up without a (good) catch can.

yeah that was an issue in the DI cobalts..
oil catch can and spraying some 75% meth should help keep mine clean..

Pardon my ignorance, but can some of you more auto savvy types explain what exactly a catch can is, or those of you who currently are using one, provide pictures? Thanks a lot in advance.

http://forums.nasioc.com/forums/showthread.php?t=754710

http://www.snailsonsteroids.co.za/ne...tch%20tank.gif
http://www.16vminiclub.com/gallery/a...ics/PCV_CC.jpg

Awesome thank you GQ.

Thats what we're here for.. :happy0180:

Now you've inspired me to push your generosity. Will just about anyone do this kind of work? Does it void warranties? and what kind of cost are we talking about with something like this, including labor?