Skidplate

Imagine boosting fuel economy in a V-8-powered large SUV by as much as 21%. General Motors (GM) is currently working with Delphi Automotive, a major global automotive supplier and also a key GM supplier, to do just that. This significant fuel-economy improvement may be possible in the near future using a new technology that can deactivate most of an engine’s cylinders during highway cruising. At the same time, the new technology could reduce emissions by nearly the same percentage.

Full story:
https://www.yahoo.com/autos/s/gm-tul...194303840.html

tblu92

The current AFM or DOD system GM is using has been troublesome---They have had many lifter failures from deactivation-- Not only does it shut off the fuel to those cylinders and spark but also solenoids in the lifter valley shuts the oil OFF to the hydraulic lifters so the valves don't open or close-- This is where the problem occurs as lubrication is compromised in the lifter bores and the lifters break---
Reading the article I see that they have a valve train engineer involved which tells me they are trying to correct the failures--- and even attempting to shut more cylinders off.
Using today's technology in my opinion and shutting off even more cylinders would create even more chances of failures unless they find a way to prevent the lubrication problem---

meyerweb

Any documentation to back of the statement that there have been "many lifter failures"? I don't recall seeing any reported on the C7 forums.

EcoBrick Bob

My son's 09' G8 GT had a DOD failure at 26K and just before the 5 yr engine warranty expired. Realize there have been many advancements since then, but basic system is the same.

Higgs Boson

There were indeed lots of issues with DoD the first few years it was out but it wasn't in vettes back then I don't think....

stab1991

Its a Corvette, make me pay a guzzler tax and let me get rid of the DOD, the AFM valves and the heavier torque tube.

SpedRacr93

My '07 Avalanche 6.0 has the same engine with no problems. 184,500 miles and counting.

meyerweb

A sample size of one is not meaningful documentation.

MitchAlsup

Imagine that your customers do not like being beta-testers--Oh my!

tblu92

As a tuner I deal with almost all the performance shops in my immediate area as well as repair shops and even dealers--Of course GM would not let this cat out of the bag but I can tell you from talking to all my customers-- they have at least 1 LS based car or Silverado a week that has had lifter failures with DOD---It seems to be worse on heavier vehicles like trucks but I've seen several cars with similar issues--- Worst case scenario--complete engine refresh-- and best case an engine flush and all new lifters/solenoids----
Worst thing is these failures almost all happen after the warranty has expired !!!! so a full price on repairs--

C6-LS2-MN6

What is your thought on the DOD Delete during a cam swap?

Higgs Boson

If you do a cam swap, keeping DoD is pure madness.

AWOL

My 07 C6 had lifter failure, my 07 Avalanche with cylinder deactivation has not. I guess having it is better for the lifters!!

Ghunt

I have a 2013 Silverado with a 6.2L and am starting to get lifter noise.
I also am not getting the milage that i was when new.
I think I better get it to the dealer quick.

blue max

Friend with 07 Tahoe with 140000 miles with cylinder deact and no problems at all. You cannot tell when they are deacted

OBSSSD

That is because the C7's out there are relatively new. GM has had tens of thousands of failures from DOD lifters in V8 applications across all platforms going back 10 years. It it literally an epidemic, and don't worry because larger numbers of the C7 engines will be joining the lifter failure party soon with all the other motors. The C7 platform has been a huge disappointment to many C6 owners, especially the Z06 with all of its problems

DOD just does not belong on a Corvette

Sir Nuke

got news for ya......you ALREADY pay the gas guzzler tax. look at your window sticker.....if you kept it that is.

0ProChargerTech

We turn off the DoD function in our tunes, due to the reasons of failure listed above. (The customer is more then welcome to turn it back on if they wish) However no MPG reduction has been found by turning the DoD system off, but the piece of mind is high knowing its disabled.

ON A PERSONAL NOTE: I used to make good side money replacing failed lifters, cams, rockers, and engines in cars/trucks that suffered DoD related failures. I can't say what the true number of failures is, but I can say that I no lack of side work for a long while, till I finally just stopped doing them.

meyerweb

I think that's true only for the Z06.