Decarbonizing GDI Engines....

[buickanddeere]

Innarresting..... as Neil Young would say ! :thumbsup:

I haven't been too impressed with fuel economy of recent engines, and had been wondering why..... unburnt fuel, DPF with gas engines....... there are many forms of tech I like, but this isn't a road I want to drive on.....

Edit - Not for the first time, what the EPA is propagating seems bass-ackwards to me...... oil also seems to be going down exhaust pipes in some modern designs (GM 5.3)...... instead of piling on more complex (read consumer expensive) tech to "solve" that problem, how about just not putting fuel and oil down there to start with ?

Your post reminds me of some reading I'd done a while back on the 3.5 EB from Ford..... some guys have taken the time to set up perhaps the sophisticated valving you refer to - I get your point - don't install a half-baked solution for a catch can.....

Being the closet luddite that I am , I'll be sticking with MPFI for a while.....

Rgds, D.

Fuel mileage has been dropping in recents years even with the more efficient drive trains . Due vehicle gross weight rising from extra safety equipment and luxury options . Check the weight of a Honda Civic from 25 years ago vs now.

 

[3930dave]

2013 Chevy Impala
58,000 miles (40,000 by us).
Still gets 31mpg on the highway just like the day we bought it.
Car still accelerates like a rocket and cruises very smooth.
Never looked into the potential problem, but may now that I'm aware of it.

I'm not sure if your's is DI.

Seems some brands may be doing goodwill maintenance....

Pros and Cons of Direct Injection Engines - Consumer Reports

Rgds, D.

 

[3930dave]

Fuel mileage has been dropping in recents years even with the more efficient drive trains . Due vehicle gross weight rising from extra safety equipment and luxury options . Check the weight of a Honda Civic from 25 years ago vs now.

That, and bloat in general - that old Civic was smaller overall than today's Fit.

Even today's small cars aren't that impressive (IMO) on the highway..... the Micra isn't rated that much higher than what Moss is actually getting in his Impala.

Rgds, D.

 

[MossRoad]

I'm not sure if your's is DI.

Seems some brands may be doing goodwill maintenance....

Pros and Cons of Direct Injection Engines - Consumer Reports

Rgds, D.

Yep. Its gasoline direct injection.

2013 Impalas only had one engine choice. The 3.6L LFX. Aluminum V6 GDI ~ 300hp.

 

[3930dave]

Yep. Its gasoline direct injection.

2013 Impalas only had one engine choice. The 3.6L LFX. Aluminum V6 GDI ~ 300hp.

GDI does spec and test-drive well.... not long ago that was sports-car territory.....

Rgds, D.

 

[5030]

Guess I'll be investing in a couple 3 spray cans of Sea Foam. Both my wife's Ford Transit Connect and my 14 Focus are GDI's. Her's is running rough so it gets it first. My Focus is getting 38 mpg average so it can wait....

 

[3930dave]

Guess I'll be investing in a couple 3 spray cans of Sea Foam. Both my wife's Ford Transit Connect and my 14 Focus are GDI's. Her's is running rough so it gets it first. My Focus is getting 38 mpg average so it can wait....

When you Foam the Transit, pls stop by and let us know how it went.

I like SF in fuel tanks, but haven't had a reason yet to use it for the thread title....

Rgds, D.

 

[Panik]

1) How is your mileage and driveability affected (Year/Make/Model pls) ?

2014 GMC Sierra 5.3L with 3.42 gearing - I have roughly ~44,000 miles on it. Anecdotally the truck does seem to run better after running a can of CRC through it prior to each oil change. It's very hard to say, in my case, if there is an actual improvement or if it is more of a placebo effect that I am imagining.

As for the separator/catch can system I am running...... take a look at the last pic I have in this post. It is the current state of my PCV filter. It appears to be removing material. How much as compared to the total amount, and how much benefit it is providing in the long term I wish I could say.

2) What are you using/doing to decarbonize the head ?

Several oil changes ago I started running a can of CRC intake valve cleaner through the system a day or so before doing the oil. Been using a flex nozzle off a can of WD40 and inserting it right before the throttle body.

I also retrofitted a Mann Hummel Pro-Vent 400 Oil Separator (i.e. catch can) to the truck at around ~20,000 miles. It is a canister filter with a replaceable paper element as opposed to the colescant filtration typically seen on other catch cans. It has a drain hole below the filter element which in typical installations for TDI engine can be routed back to the oil sump. In my case I routed it to an additional collection sump below my bumper to eliminate any possible concerns with contamination. When I have emptied the sump I have only really seen water condensate in the collection area. A big plus for this layout is that it pretty much eliminates any concerns I have with condensate freezing in the main filter area and clogging the system.

3) How often do you need to do it ?

I've been using CRC every oil change so at ~7K intervals. I believe the instructions on the spray can recommend every 10K. As for the Pro-Vent, I check the condensate canister every month and will be changing the filter this next oil change. I'm pretty sure the instructions for filter changes recommend once a year depending on soot levels - and I am actually due to change the filter this next oil change.

4) If not DIY, what are you paying to get this done ?

Mine is DIY so I can't really assist with this question.

Would not recommend a catch can either, especially in cold climates where they can freeze up, not allowing your crankcase to breath at all. Plus, if the system is not set up correctly with the proper evacuation with check valves, you're doing more harm to the engine than good.

Snobdds - I would be really interested to hear more of thoughts about the issue of check valves and evacuation. The last thing I would like to do is to cause damage to my truck's engine. My understanding, and it is limited, is that check valves for the 5.3L eco-tec engines were only necessary when you run a clean side separator system in addition to the more typical PCV catch can installation. As for freezing up, I'm hopeful that I eliminated that concern with having a condensate sump that drains from the bottom of the filter housing. Seriously, if I am missing something I would really appreciate a critique of the system I installed.

My Setup:

Filter and condensate sump location


Filter canister with and without paper filter (drain in 2nd pic leads to the condensate sump below the bumper)


Current state of the paper filter

 

[ch1ch2]

Back in the day, I had a 425 hp 396 chevy. It would build up carbon and diesel when I tried to shut it off. I would turn the key back on and let it run while slowly pouring a glass of water down the carb. After that it seem to run better and did not have any dieseling issues.
The slowly poured water would break up the carbon and it would flake off.

 

[3930dave]

Back in the day, I had a 425 hp 396 chevy. It would build up carbon and diesel when I tried to shut it off. I would turn the key back on and let it run while slowly pouring a glass of water down the carb. After that it seem to run better and did not have any dieseling issues.
The slowly poured water would break up the carbon and it would flake off.

What is old is new again.... this modern GDI issue reminds me too of problems with old carb'd engines.....

To me, this is where GDI really is a step backwards. Hands-on TBN types will learn about these GDI problems, and try to solve 'em. However, while many consumers today might change the oil, they often will ignore other maintenance until it becomes a major drive-ability issue..... you could mostly get away with this with MPFI, and this is what people (consciously or otherwise) now count on....

Rgds, D.