DOD (Displacement On Demand) system in NSW Highway Patrol Cars

[Forg]

Yes our flex-fuel MY14 SS is auto & is AFM.
The aforementioned VE2 is either manual or it came from the factory with AFM.

 

[2012 Vess Ute]

Is it a manual?

Yes it is

 

[lmoengnr]

Yes it is

It's an L77, all have DOD, just wasn't enabled on manual Commodores.

 

[VS 5.0]

It's an L77, all have DOD, just wasn't enabled on manual Commodores.

Do manual L77s suffer from the same issues as auto cars with DOD activated ?

Or less likely coz the lifters are always in active state ?

 

[Skylarking]

Do manual L77s suffer from the same issues as auto cars with DOD activated ?

Or less likely coz the lifters are always in active state ?

Interesting question but considering it another way, what causes DOD issues?

I thought is was poor oil servicing that was the root cause for the majority of DOD failures. Primarily oil pressure via VLOM solenoid caused the lifters to collapse and dirty oil results in the collapsed lifter sticking in its collapsed stated for longer than desired. This places stress on internal DOD lifter locking pin and/or the lifter roller/cam surface caused some wear.

If this is the case, and I’m no expert, then if one never collapses the lifters using VLOM oil pressure directed to the specific DOD lifter collapse port, then their shouldn’t be much of an issue.

However, the DOD lifter were revised to improve oil upper chamber volume and oil bleed down (retention) to reduce cold start noise This seems to implied the earlier ones were noisy on cold start. Such noise is from tapping due to lash not being taken up by oil pressure (the main function of any lifter be it DOD or not). So a lifter design issue and again an oil cleanliness issue. So, if cold start noise is an issue in older engines which may not have the revised DOD lifters, there could still be potential for lifter roller/cam surface damage which ain’t good and may lead to bigger failure...

Seems keeping the engine oil clean, warming up the engine before giving it stick and not revving past 5800/6000 rpm is probably your best insurance from any LS lifter failures. So it’s not a DOD specific issue per se, just poor maintenance that seems to lead to failures...

Sadly no one outside GM engineering would know the failure rates of lifters, be they active DOD, passive DOD or even non DOD lifters and I doubt they are talking

This and this are always an interesting read, and likely many many more

 

[VS 5.0]

Seems keeping the engine oil clean, warming up the engine before giving it stick and not revving past 5800/6000 rpm is probably your best

All of those boxes are ticked.

 

[lmoengnr]

Do manual L77s suffer from the same issues as auto cars with DOD activated ?

Or less likely coz the lifters are always in active state ?

I have no idea, I've only ever read about L77 DOD failures.
I service a few for friends, and friends of friends, mostly auto's, but 2 manuals, no complaints of lifter noise.
They are all VE's, and none have any piston slap either. That seems to be a VF problem...

 

[LyLy]

I had the ve9.5 ss Ute with afm, before the vf2 Ute sv6
It Ran great I went to Adelaide from Melbourne at night time on one tank of fuel
Set the cruise to 110 and let it do it’s thing, it was excellent on fuel
It’s a shame Holden dropped it .
when mine was in for service the dealer mentioned that when the car goes above 140km it does something to stuff it up they had 4 cars in with same afm problem. But guessing it’s luck of the draw same with any Holden,
I found the fuel economy from the ve ss was much better than the vf2 sv6
If Holden kept the afm in the vf2 I would have bought the ss
But as usual they tried to copy Chrysler and it failed

 

[MACVESSV]

I bought a stock one owner 12 months ago, a VE2 SS Thunder UTE 2012, with the auto and it had DOD/AFM. It told you the 8 or 4 cyclinder modes it switched to in the centre LCD instrument cluster screen, but you could not manually turn it off, which was pretty crazy really.
It was not very fuel efficient, and at 260kw I was not happy with the power, as I also own an late MY17 VF2 SSV Redline M6 with the Walkinshaw 407 kit and custom tuned, the difference in power was huge, so I had the ute dyno tuned to 371 rwkw with added upgrades to intake etc, which involved having the DOD/AFM deleted from the tune, but the hardware is still fitted. It drastically improved my fuel economy when cruising and took away the drone from the exhaust in V4 mode.

Also as far as I'm aware, the VF S1 V8 did not have AFM, as I also owned a MY14 VF1 SSV Redline M6 for 4 years before my buying new my VF2 Redline and an auto was an option for me and I was advised the AFM was not included in the VF models at all.

 

[lmoengnr]

Also as far as I'm aware, the VF S1 V8 did not have AFM, as I also owned a MY14 VF1 SSV Redline M6 for 4 years before my buying new my VF2 Redline and an auto was an option for me and I was advised the AFM was not included in the VF models at all.

All VF1's had L77's fitted, manuals had DOD capability, but it was disabled in the tune.