When direct injection came onto the scene 10 to 15 years ago, it seemed to cure many of the world’s problems, offering more power and improved fuel economy. Where traditional injection setups squirt the fuel into the intake port, direct injection delivers a very precise amount of fuel right into the combustion chamber.
But a problem tended to crop up: …
So, those with GDI engines, what are you finding? All going well? Using some kind of intake cleaner? Is walnut shell blasting part of your maintenance schedule?
In reply to David S. Wallens :
Not every DI engine suffer from intake system deposits the same. Some are really bad some barely have any.
With R56 MINI's the answer is a catch can system.
I hate to say it but "Staff Writer" really phoned that article in. I clicked the link genuinely interested in a solution and was instead told to buy gasoline that won't have any effect and then a "perhaps these chemicals we have no experience with might help"
Cool, another Sunoco advertisement. 
Trent said:With R56 MINI's the answer is a catch can system.
I hate to say it but "Staff Writer" really phoned that article in. I clicked the link genuinely interested in a solution and was instead told to buy gasoline that won't have any effect and then a "perhaps these chemicals we have no experience with might help"
Agreed.
People: What's the solution to DI engine sludge build up?
"Staff Writer:" lol ¯\_(ツ)_/¯
About as good advice as: Buy a new car that has both direct and port injection so you get the best of both worlds:)
In the Korean world catch cans are a lifesaver. Seafoam through the pcv hose helps. On some honda vehicles a friend that runs an independent shop does he walnut shell treatment but pulling the intakes.
Monitor oil consumption. Use a catch can if you can and keep a fresh PCV valve on. If it's been ignored too long original seafoam or GM Top engine cleaner works decently but makes a helluva smoke show. Finally you can have a shop (or if you're adventurous) use walnut shells to blast the valves/ports.
EDIT: maybe I need to start writing for y'all
I've run a couple of cans of this stuff through the Expedition:
It's honestly hard to know how much of a difference it's made without getting a borescope and peeking down into the heads. At 85k miles, the truck still runs great, makes (seemingly) full power and gets the same crappy fuel economy it always has. The one symptom of buildup that it does have is that it idles rough when it's cold. I've looked into walnut blasting. Interestingly, it was easier for me to find places that do do that for VW and BMW engines around here than my Ecoboost 3.5, which is in approximately a zillion vehicles in the Detroit area.
With the EGR valve failure last year, (due to carbon buildup) I suspect at some point we'll do the walnut shell treatments. But till then, we've been running a 70/30 mix of fuel. 70% reg & 30% eFuels. I can go slightly higher on the eFuels. But last time we got a lean code.
My Buick with the LCV Ecotech 2.5 just turned 100k miles, DI no issues yet.
Boroscope is on my Xmas list for investigating. This is a non EGR engine, interwebs tell me that there is a tube that can get plugged, still waiting for a CEL.
In reply to FlordPerformance :
What engine are you doing this on? And that's an odd blend of fuels- pretty much every recent F production engine can run e20 if it's not flex fuel.
In reply to alfadriver :
Nice info.. we're running a 2.0l I4 GDI and it's always confused us on the Ford site.. it says that our 2.0L is a flex fuel engine and we could run E85. But the last time we went full bore with E85, we got a lean code. Plus there's no yellow cap on the van as it doesn't use caps with the easy fill system. However under the van on the tank, there are several yellow connectors. Again according to Ford emails to us.. the 2.0L can run on a mix of fuels which we've done. So in actuality, if the regular gas has 10% ethanol added.. then our ratio would be 60/40 and not 70/30.
I had been running a half can of seafoam through all the GDI's every 15k miles through the pcv vacuum hose. Now I use the CRC that TomSpangler posted. It seems to work better, using less product.
Rio is at 130k miles, Forte is at 20k and the wifes previous Rio had 144d when we traded it in. The only issue from all three are my rio burning oil, but it's seen some **** since I bought it at 80k miles
Luckily, none of the Korean cars run EGR to make things messier than they already get. One thing I have been noticing with the Rio though, the euro-spec (VW/BMW) oils do not seem to burn as readily as the Dexos rated oils in the same viscosities. The ratings they use are a bit different and what I can see for additive differences the euro spec fluids seem to be designed to work a little better with direct injection than the dexos and dexos II fluids.
In reply to FlordPerformance :
Can be flex fuel and actually being it is different, for sure. I know that e85 is a natural fit for DI in terms of alcohol and combustion. But DI systems can be fuel volume flow limited, so some engine configurations can't actually run peak power on e85 as the system can't pump that much fuel.
I will add, that at least once a month I have to disable the throttle body and clean the butterfly/flap as it's been getting gunked up with sludge from the breather hose leading off of the valve cover down to the intake tube. I've noticed an improved throttle response when doing this, but I was thinking a oil catch can would be needed somewhere along the vent hose. However, I live in a CARB state and it would be illegal to add a catch can. Same holds true for the throttle body spacer off a Ford Maverick as Boomba racing has designed one for the 3 bolt pattern throttle body.
In reply to FlordPerformance :
You should be able to find an approved oil separator that is still closed loop to return the oil in the sump.
According to the Ford engine diagram, there is a oil separator/catch can located under the header/exhaust and it's a flush fit device. No where near the main vent line coming off the top of the valve cover. So you're saying there should be something I can add to this vent hose but not be an actual catch can? The issue is, the air intake draws oils and waste from the top of the valve cover through the hose and out into the intake down into the throttle body flapper.. maybe all thats needed is a new vent hose.
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