I'm looking at a 2014 Corvette with a "ENGINE 6.2L (376 CI) V8 DI (455 hp [339.3 kW] @ 6000 rpm 460 lb-ft of torque [621.0 N-m] @ 4600 rpm)". I've heard some bad things about GDI, such as carboning up the intake valves, diluting the crankcase oil, etc. I would appreciate any insight/experience with this particular setup. Everything about the car is perfect, except I'm leery of GDI.

After further research I believe this is an LT1 and it has VVT (variable valve timing) which again seems like needless complexity. Input/opinions?

This message has been edited. Last edited by: Canted Valve,

We have an Acadia with gdi. Not a v8,a v6, but same principle. Also has vvt. 78xxx miles has been trouble free. Change oil/filter every 5000 miles. Air and fuel filter 15000 miles. My wife is the primary driver and drives it like she stole it all the time. From what I researched that is actually best for it as far as preventing carbon build up. I do worry about the timing chain and guides however. May just get them changed out around 100xxx. Power and throttle responds is very good, so far we like it. Hope it helps.

I have not seen any issues related to GDI.

That being said, I believe that without gasoline constantly cleaning the backside of the intake valves, I would think there is the potential of build-up on the valves. Haven't seen it though.

My wife's '16 CR-V has GDI and for a 4 cylinder is has a surprising amount of low end torque compared to earlier CR-V's with the same engine with port injection.

quote:

My wife's '16 CR-V has GDI and for a 4 cylinder

Is it an "Earth Dreams Technology, i-VTEC"? If you can get through this goofy guy til 4'05" he points out the gasoline dilution issue.

quote:

...has a surprising amount of low end torque compared to earlier CR-V's with the same engine with port injection.

I don't question the performance advantage. It's long term reliability and "unintended consequences" of new yet unproven technology. At least in it's early stages.

Not sure about the oil dilution issue. Guess I'll pay more attention to the oil when I change it.

This guy is probably smoking something illegal every day. Seems like a real douche nugget.......

Have not seen any problems with carbon build up. I have seen some injector issues on the full size trucks from pluging up with missfires and SES lights coming on . Seen a few 6.2s in the full size trucks and SUVs have cam issues. Most of the timing chain failure on the 3.6 V6 are caused from lack of oil changes.

quote:

Seen a few 6.2s in the full size trucks and SUVs have cam issues.

And those "cam issues" would be...... VVT related?

I change the oil in our Acadia myself. I have not noticed any dilution of the oil that I can tell. I change it a 5000 miles instead of relying on the oil life monitor. The monitor will go close to 10000 miles to a change. My hope is to avoid the timing chain issues. Always use valvoline 5w30 synthetic and wix/Napa filters.

quote:

I have not noticed any dilution of the oil that I can tell.

Thanks! Appreciate the real world input.

As an aside, I got an oil analysis on a 4.6L Ford mod motor. They recommended I change it a 6K miles. Shell Rotella T6 5w40 full syn.

Lifter wheels taking lobes out and found one with a small chunk of metal broken out on the closing side causing a high RPM miss but did'nt make any noise. That was fun to find. We don't have any way to check them at work but i think some of the cam cores are soft.

quote:

That was fun to find.

I bet it was! This latest iteration of the LT-1 is alleged to have a billet cam, hopefully it's up to the job. I'm sure it needs it as it has a tri-lobe that drives the high pressure GDI fuel pump. Oh, this engine management system shuts down 4 cyl., when possible, to try and satisfy the guvments ever intrusive demands. Needless complexity looking for an opportunity to fail.

Yeah my friend & I were just talking about new cars and their mandated complexities. My turd is an antique....nothing to worry about. Even if I gotta put a couple hundred into it every now & then, it's still WAY cheaper to keep/maintain than anything 2005 or newer--and that's the way it's going to be, at least for me. My truck is an 03 and it's complex enough. I work on stuff daily and these newer diesels? Just stupid. I had to replace the supply pump on a tractor yesterday, just like working on a modern diesel truck....start taking stuff apart and a few hours and a pile of parts later, you're down to where you need to be. $5000 for a supply pump including labor....on a tractor. That's 1/4 the cost of a new one. 33hp tractor at that. Thank you Mr Government.

Girlfriend has an 09 acadia. I read up on timing chains. Told her if it starts to pick up a rough idle and/or code, we are selling it pronto. Ain't no way I'm going to put chains in it. Besides, that car has not been trouble free, it's little stuff every time she drives it-from the day she bought it (new).

Lot of online chatter about catch cans being able to avoid the carbon build up issue. I dunno.

I believe any valve carbon issues are caused by cheap/wrong grade motor oil combined with lack of proper maintenance. An engineer (from GM) told me once that inferior gasoline could also cause carbon build up on the valves. Seems strange to me since the back of the valves don't actually "see" gas. He's an engineer though. GM (as well as me) recommends using "top tier" gasoline. "Top tier" brands have a specific additive package. Around here the brands listed on the top tier website are the same price as "other" brands.