There's concern around oil building up on the back sides of the valves that could potentially cause issues but I've never read where anyone has actually had an issue with it. My last L83 I pulled the intake at a 168k miles and the build up was minimal at best and this was with no catch can.
CK5
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I'm late to this party and I mostly skipped everything. I say boo to any small-block or any trans with more than 6 gears. Just my opinion. It's a big truck, needs a big block or a diesel.
every recent gas powered dgi has had motor failures early, Class action law suits, that the mfr's lost Honda, Subaru, Kia, Hyundai, all replaced engines on the DGI cars. My kids were just given a 2015 kia Forte, it has a lifetime engine warranty, transferable to current owner. Only Toyota which hadn't gone to DGI as of 2020.
I have no proof, but in my mind the the high pressure spray of gas into the cylinder either washes down one spot on the wall, or eats away at the piston.
Had a 2015 Chevy Silverado 1500 with the direct injected 5.3L go 65k and over 14k idle hours and never had issues til it lost a lifter. Never touched the fuel system. Sister truck to that one (we have 3 with sequential vins) needed a set of injectors at like 20k miles. It's only at 27k currently.
My 2019 5.3L never had injection issues in the 5 years and 119,000 miles I had it. The exhaust valves got me. I was apparently an abnormality.
I don't think the LT series GenV SB V8s have issues like that with GDI. The L8T is basically the same as the L83 or L86, both can go a long time and have been around since 2014, the cylinder deactivation is what can get them early and the L8T doesn't have those lifters.
They can potentially have carbon buildup on the intake valve, buts that more of a degrading flow issue than a reliability issue.
I think the key with any of these things is still proper oil changes, and that doesn't mean 10K miles, I change mine at 5K with full synthetic. I also use Pennzoil Ultra Platinum because I think it keeps things cleaner inside the engine and reduces these issues, but that is just my opinion.
This ^^
I was recently saying this same thing that you never want to wait for the OLM to tell you. I try to do it at 50%. The oil nowadays is lubing the bearings, actuating the cam phasers, tensioning the timing chain, opening AFM lifters and maybe lubing a hot turbo. A lot of the issues are from sludge that would have been a non-issue in an old SBC. The OLM is set to cut the service costs during warranty and appear as a convenience for the new car buyer, not based on what's best for the lifetime of the engine. Of course, the new car drivers were just giving me blank stares...
Oil analysis is scientific, but I've always thought it focused more on wear and lubrication than detecting buildup
I assume the cylinder deactivation can be tuned out? Understand for 99% of the vehicles out there that wont ever get a tune, that would be an issue, but would that fix one of its ‘liabilities’ when swapping one in for a build? Guess mileage of the motor at that point would matter, so disassembly/inspection would be important
It can be turned off with a plug in module yes.
I am not sure if that fixes the issue because I have not changed one of those failed lifters myself, so I am not sure what part of the lifter is failing, and if turning it off and leaving it alone would solve the problem, I don't know, sorry.
I am not sure if that fixes the issue because I have not changed one of those failed lifters myself, so I am not sure what part of the lifter is failing, and if turning it off and leaving it alone would solve the problem, I don't know, sorry.
Doesnt getting rid of cylinder deactivation also require a cam swap?
Yes. To physically do it.
I've known one person who still had a failure on one even when running one of those plug in modules since brand new. It was over a 100k though. I turned mine off in my tunes.
Thats fine, can always use a little chop
As far as build up on the back of the intake valve goes i think it is when it interferes with closing,then the valve margins burn.
Toyota went to the trouble to have both ported and direct on their M series engine.
Eventually the guides are going to go on any engine, won't be able to as long with a smokey start up on gdi as ported
Toyota went to the trouble to have both ported and direct on their M series engine.
Eventually the guides are going to go on any engine, won't be able to as long with a smokey start up on gdi as ported
What I'd read about the DI stuff isn't necessarily the DI's fault. It's the EGR that's causing the problem. Blowing its ass-gas back into the intake and that causing the buildup. The port injectors can clean that crud off, but DI injectors never have the chance.
If you could get rid of the EGR system and only feed it fresh, clean air. They'd prob work just fine.
If you could get rid of the EGR system and only feed it fresh, clean air. They'd prob work just fine.
So remove emissions garbage and everything works better? What a novel concept.
Yes and some of the yota engineers admitted it doesn't solve the problem, a good PVC baffling system solves the problem. GM has drastically improved the PVC baffling on the engines vs non GDI engines. A catch can could potentially help, but there is no evidence that solves the problem either, the only "evidence" is people saying "but look what I caught in it". OK, does that fix anything? Or did you catch oil vapors along with condensation that would of maybe cleaned it a tad and nothing changed? Certainly no automaker would expect their customers to empty that. The proper way to do it is basically a built in baffle/catch can that self drains back into the crankcase where any vapors can get steamed out and you are left with oil again and no draining schedule. A baffle in the valve cover or wherever you are pulling the vapors from solves this.
Thus far I have not seen a single person that has done a side by side with a can or without. I actually ran a can on mine for the 80K I had the L86. But I never pulled the intake to inspect it. I changed the oil often and with good oil so even if it was clean it doesn't mean it was the can, could of been my maintenance. Sold the truck, and put the can on the L8T, I might be wasting my time, but I figure it likely can't hurt, its basically just an expansion filter for the PVC system that I have to empty once (sometimes twice in the winter) per oil change.
I still think the most important thing is change the oil often enough and use good oil that helps keep the engine clean.
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I don't think these LT engines have EGR that I have seen?
The oil doesn't get burned until it hits the hot intake valve.
The modern diesels definitely do, and you can't idle them a lot like you used to or they will crud up, not just the intake valves, the whole tract from the EGR sooting up to the crud in the intake between the EGR opening and the combustion chamber.
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Makes sense.
