kennerz

Just an FYI my DoD has been disabled for a long time, since like 30k mi, and I'm at 87k now.

Would agree it needs to be larger and have some type of trap/filter something to be more effective. What the small ones on the vettes/camaros actually accomplishes would be really surprising if it does anything meaningful. I've heard that same info about the DI ecotec (2.4) that they have a deficient PVC system, especially for performance applications. Anyhow, the whole exercise here is just another data point. Don't know that I'm going to change anything about my program, I don't know with certainty what to change to get a better result. And to me a better result would be keeping the intake tract clean. Another thing about the CDI cleaner if used the way they intend you too. You will inadvertently wash a bunch of garbage into your cylinders, some of it is on the harder side. If I did use a liquid chemical induction cleaner I would change the oil within the 1st 100mi. for sure.

Would make sure to change the oil asap, that stuff gets past everything. I used a little on my cleaning exercise directly. The oil was absolutely filthy after the cleaning. Can dilute the oil...

The guys that sold catch cans on here already made there money, too bad. I was in their camp/made sense, but after seeing the results it would have to be a thumbs down to the catch can (don't care who's you have, or for how much). Just put this up in hopes of somebody on the fence in the future won't spend the money. Conceptually they are fantastic, in real world execution & observation over time they don't make enough of a difference to justify IMHO./They don't stop the problem at all... Validated results.

There you go, mine were similar but worse than Wingsaa's with 33k additional miles on the clock. My AFM was disabled as well at around 30K. We probably don't have a large enough sample to say anything for sure, but I believe they need semi regular cleaning to be maintained at their highest potential. I also run 0~40w euro blend oil. either amsoil or carstrol syntec. Could be heavier vapor. Would think the only way to stop this would be to re-route anything that flows from the crankcase to the intake and stick a filter on it. TO me DI is a little bit of a problem maintenance wise. As wingsaa mentioned the contortion act around the engine bay was not very comfortable while cleaning. I think the walnut shells is a great way to do it, just a pain prob. had about $160 or so in tools/materials to do it. But I hear normally shops charge $400+ then you need a good shop to take it to (I am my own good shop). But, I will agree that I can't say exactly how effective the catch can was, or was not. It does prevent some amount of vapor that you have to catch and dump. I can't see how you would want the factory set up pulling directly into the intake, would have to think that makes it worse, but cannot prove that. Catch can proves inconclusive to me. Really hard to say it does anything positive, just I've dumped a couple of quarts out over the years, usually just a few ounces each oil change. Truck does not really loose or burn any noticeable amount of oil. Would also think that there are a ton of these truck that are high mileage that are impacted. I did not "feel" the effect of the problem until I cleaned it, meaning it drove fine, was a little down on power and mileage suffered a little, it's just so gradual you don't hardly notice. But once clean your like OH, much better. Depend how sensitive your butt meter is too. If your keeping your vehicle for whatever reason, I would plan on doing this sometime soon, anything over 50K miles.

A couple more, sorry for the GIF format, new phone.... The stems had a buildup a few millimeters thick. Wish I would have taken after pics, was getting tired. The after cleaning results were dramatically cleaner, like new bare ports in some places. Only thing is you would need some type of angled pick to use to get at the short side radius. Everything else looked near pristine.

I'm just sharing information. My experience, some people may find it valuable. So don't have to pee on the thread. Maybe proves the can doesn't work? or even contributes? I've seen worse than my truck on here and that one 104K pic does not look that great to me. I've seen high mileage tuned ports and LS1's that are not a fraction of that dirty, so no those are not "good looking " ports to me. Clean motors run better, sorry if you guys disagree with that, it's OK. There could be other factors, who knows. Running mostly amsoil. Truck was running absolutely fine, I did it because I'm aware of the problem and wanted to follow up on my old statements in this tread to hopefully support the community here, that's it. More of general maintenance. I still plan on keeping the truck.

Probably leaning out to match the restriction in airflow over time. I have a L86 so maybe this does not effect you. All I know that if you pull your intake and look at the valves I would bet they don't look so hot. Also if they were properly cleaned I would bet that you would see a measurable difference.

I'm running an AFE GT momentum intake too, so all the lines directly to the intake are re-routed. The only line that feeds the intake is the one for tha catch can. Point is , this buildup is real, the performance impact (which has been well documented on other DI vehicles) is real. And if you plan on keeping your vehicle for any period of time I recommend you somehow clean the intake valves. I choose walnut blasting which is arguably the best approach. The intake ports looked very clean when I was done, like I mentioned some scraping was still required, and cleaned with CRC intake cleaner and carb cleaner to help break the stuff up some. For the walnut blasting I used a wand from ECM tuning, and ordered a plastic port fitting that attached to a shop vac to collect the walnut shells. through ebay for a L86. Cleaned the manifold while I was at it. Used a harbor freight 20lbs blaster. Using a 6hp craftsman compressor rated at up to 8.5 or so cfm. (this is critical that you have enough flow from the compressor). Watched a few youtube BMW and mini cooper DI cleaning videos to get an Idea on how to do it, Hardest part was getting the intake cover off. (I cut it off with a cut off wheel and sawzall) it is that much of a pain and the more I researched there is no easy way to remove but your mileage may vary. I say it's around a 4hour job give or take. Hard to get to the back ports too. I may do it again in 10k or so should be much easier with the cover now removed. Maybe less than 3 hours. Oh, and if you can get the cover off easily - good for you.

Here you go Grumpy, They look like crap, standard DI high mileage. The film was not good, the thick carbon gunk was unlike anything I've seen before, can't be good for anything. Truck runs much better now. Those are tyhe middle of the road ones, some a little better, some worse. The Walnut blast and scrape got them about 90% clean. (Hard to get the short side radius of the valve). What you can't see in the photo is the buildup on the tulip of the valve that has to kill low lift flow, it was worse than the picture tells.

Back from the dead, I performed a walnut blast intake valve cleaning recently, will upload pics of the before on a few of the valves. This is a serious problem. The only reason they don't absolutely run horrible is cause the intake runners in the heads are huge and the valve lift from the cam is huge too. There was soo much of this disgusting carbon like thick jelly and dirt/oil everywhere killed the low lift air flow over the valves. I immediately picked up 1.5~2 mpg and power increase/return is almost dramatic. Truck is a rocket again. Like the frog in boiling water analogy it (DI carbon buildup) is so gradual that you don't notice how bad it is. I don't care what anyone says, it is a problem on these motors once you get up in miles and I'm sure significant buildup occurs well before you notice it. With post details on another new thread, how to, what I used, Was able to get them way cleaner with the walnuts over any other method. Was kinda a pain overall though. At least a half-days work taking your time. If your truck has over 50k mi I would say it needs it. Mine was at 87k and was shocking to me and this was running an elite catch can, so who know how much that may have slowed it down.

Build up like that effects low lift. Probably happens gradually enough that you would not notice the 1 or 2 mpg and 10 to 20 hp. Looks like enough to impact performance to me. I would get it walnut blasted at this point. When I pull mine after running a can with about the same mileage we can compare.

If you are not comfortable tuning I would do the HPT and find a competent tuner. Did the I3 and diablew. He made standard changes and made it better. He provides a solid service for basic changes. That said I would find a "guru" and get the thing all the way tuned up meaning FUELING, TIMING, TRANS TQ MANAGEMENT, Cam phasing AND ALL THE SECRETS . The new GM stuff is super complicated with all the tables and relationships not LS simple. 1slow is correct if you are the patient type and want to learn it, there isn't any real limitations. Just for a lot of us who can learn and have ability sometimes time is the constraint.

2" is small for a 5500 lb vehicle. 2.5" with large shafts to me is adequate, but you could easily do 3" and not be over dampened. Depend on a lot of other factors of course. I really wish they did not take so long to release, would have saved me some money. Instead went all out on good 2.5's. Do make a big difference but not cheap. Glad you all like what you got, Bilstein is hard to beat for value.

Fattyz - Looks good. Dieselfan1 - I'm running the 33x12.5-r22 on a 10 wide rim. Of the choices with a stock rim the 305/45r22 would probably be the way to go. Much lighter than the other options like 10~15lbs per tire. The 33x12.50r22 is noticeably heavier and you get punished in all performance aspects, with the exception of they off road better/ride slightly better..