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L77 - AFM/DOD improved over time. But high oil consumption?

Discussion in 'VF Holden Commodore (2013 - 2017)' started by CliveSS, Oct 24, 2019.

  1. CliveSS

    CliveSS New Member

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    There are many posts relating to AFM/DOD lifter failure. Also several posts on the improvements made to AFM/DOD over time - (thank you Monstar). I am interested in AFM/DOD, not so much from a performance point of view but really to understand any potential reliability issues which are likely to arise from the system.

    My unmodified 2006 VZ Thunder auto has an L76 with AFM/DOD hardware that is not activated. From what I have gleaned the hardware consists largely of: softer profile cam (than non AFM/DOD, special valley plate containing solenoids (VLOM), two part lifters on 4 cylinders.

    On my auto transmission L76 motor (and I understand on L76 and L77 manual transmission models) the AFM/DOD is disabled by the factory settings to the ECU software. In essence the solenoids in the valley plate/VLOM do not actuate. They are in a permanently closed position and hence oil under pressure is not diverted to the two part lifters. The lifter pins are therefore permanently in the default locked position and to all intents and purposes operate as a "normal lifter".

    It is widely reported that AFM/DOD lifters in early L76/L77 motors have issues with sticking. In other words the main lifter spring (not the latch pins spring) will be stuck in the compressed position. The effect is that the lifter and push rod assembly are in a shortened state and float between the camshaft lobe and the valve rocker. A ticking or clattering sound results from the lifter and push rod assembly being bounced off the rotating camshaft lobe. Damage to camshaft and lifter will likely occur if the problem is not addressed.

    As a sidebar, my L76 motor has AFM/DOD disabled and since the lifters are not subject to opening and closing I assume that they would not be subject to "sticking". They would not need to be replaced or upgraded - bearing in mind that I am referring to a stock motor with no performance mod's. Hence any ticking noises coming from any (L76/L77) deactivated AFM/DOD motor is unlikely to be due to faulty lifters. Would anyone like to comment on this?

    Returning to the matter of sticking lifters, there is a very informative AC Delco u-tube clip (Oct 2018) explaining the operation of AFM/DOD lifters. It explains that lifter failure is almost always a symptom and not the cause of engine damage. It can be caused by a mistimed switching event brought about by low oil pressure VLOM issues etc. etc. That seems to support other posts which report persisting problems despite replacing damaged lifters. Watch the video clip for details.

    I have seen another u-tube clip (don't recall title or date) which suggests that the lifter bores are extremely tolerance critical. The bores should be checked before replacing lifters.

    As per para' 1, Monstar notes that AFM/DOD systems have been improved over time. If I am reading his posts correctly it appears that by VF series 1, L77 motors will have a set up as good as it gets. They incorporate Delphi II lifters and several other mod's to increase efficiency and reliability.

    However there have been several posting about high oil consumption on some engines. Low km's units and apparently in good order where high oil consumption would not be expected. I am unsure whether that is only on AFM/DOD active motors or if it also applies to de-activated systems? It seems that high oil consumption is associated with AFM/DOD enabled motors.

    I read on another forum/post (don't recall title or date) that high oil consumption on AFM/DOD active engines is a direct result of AFM/DOD. It appears that on extended low throttle/light load freeway cruising (when 4 cylinders are de-activated) the de-activated cylinders are subject to excessive oil build up (and/or petrol?) which burns when the cylinders are put under load and the cylinders are re-activated. Over time/mileage the piston rings "gum up" resulting in high oil consumption.

    I would appreciate any comments on the above; particularly in relation to high oil consumption issues. Any comments at all would be useful, but the following info might help to shed some light on the issue(s):-

    Engine: e.g. L76/L77
    Mod's or standard
    Model year:
    Total km's
    Oil consumption
    Auto or manual
    DOD present or not
    DOD enabled or disabled

    If you've read the post to this point you must be keen! Hope some useful information comes back.



     
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  2. Ron Burgundy

    Ron Burgundy Well-Known Member

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    Wow that's long post...

    Does you engine have any issues / unusual noises ?
     
  3. CliveSS

    CliveSS New Member

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    Why?
     
  4. Ron Burgundy

    Ron Burgundy Well-Known Member

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    Because I am struggling to see what the actual question is ... What is the issue ?

    Unless it's simply a broad discussion around the topic you raised ?
     
  5. CliveSS

    CliveSS New Member

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    Thanks Ron,

    Yes, the point of my post is "to understand any potential reliability issues which are likely to arise from the system". I used the example of my own L76 to provide context, not to resolve a specific issue.

    My long post provides (hopefully) some useful information for those interested in DOD. Also some assumptions; some of which may be erroneous. Any relevant feedback is welcome.

    I have bolded text in para' 5 which invites comment. Also para' 11 asks for further comments.

    Hope that clarifies.
     
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  6. Skylarking

    Skylarking Well-Known Member

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    Don’t know technical details about AFM/DOD but if any concerns exist about oil consumption, the question that pops into my mind is how much is consumes between services?

    If it’s more than the amount between the high and low marks on the dipstick (1 litre?) between services (15,000kms) then I’d consider it a fault which Holden should fix under Australian Consumer Law (ACL) statutory warranty, even if outside manufacturers warranty period.

    The whys and why nots of oil consumption are not really relevant as any more than 1 litre per 15,000 kms is outside service intervals which would indicate something is wrong. And when one buys a car it comes with a certain service schedule which can’t be changed after the fact (that would be a bait and switch) so Holden can’t suggest intermediate top ups between service; that won’t hold.

    As for deactivated AFM/DOD hardware, and ticking noises, if there is any abnormal noises Holden needs to sort it out under ACL as an engine should last much longer than the manufacturers warranty of 3 years 60,000kms. Heck, maintaining scheduled services should allow the engine to work for more than a decade without valve train rebuilds. If an engine with deactivated AFM/DOD hardware has a higher failure rate for the AFM/DOD bits than the other parts of the valve train, then obviously Holden has mis-stepped by taking the cheap software approach rather than producing a different variant of hardware (without AFM/DOD) - so I’d expect Holden should handle the issue under your ACL statutory warranty.

    Having said that, mainly due to AFM/DOD’s need for super clean oil, and as extra insurance, I would consider doing a mid service schedule oil & filter change (as many forum members often recommend).

    So, buy from a dealer and allow ACL statutory warranty to work for you rather than worry about a potential engineering issues or non event.
     
  7. abuch47

    abuch47 Active Member

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  8. 426Cuda

    426Cuda SUBLIME!

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    Interesting thread CliveSS.
    I've owned my auto VF Redline since new (Oct 2013). It's been moded most of its life and has always enjoyed a good romp across the tacho type workout. Mods include headers, hi-flow cats, 2.5" exhaust, OTR CAI, engine and trans tune. Roughly 260rwkw. The tune included broadening the AFM band / parameters and also making the most of the E85 flex fuel capability (st my request and also as suggested by Pir4te / Monstar).
    I've had no real issues with the car to speak of.
    Engine: e.g. L76/L77
    Mod's or standard: mods as above + brakes ;-).
    Model year: 2013
    Total km's ~87,000
    Oil consumption: too small to measure. I.e. negligible.
    Auto or manual: Auto
    DOD present or not: Present, active and tuned for
    DOD enabled or disabled. Enabled.
    Oil changed at ~ 8,000km intervals (Penrith HPR 5W40 Enviro).
    Usually run on a 70/30 ratio of e10 & e85 respectively. Gets good economy, and power for about the same prIce as 91RON. It runs better than new.
    Cheers,
     
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  9. Forg

    Forg Well-Known Member

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    Because if you averaged out the availability of E85 across all of Sydney it would round to 0, we use PULP98 in our bought-new-by-us 2014 SSVR.
    Opposite of 426Cuda's, dead stock & my wife putters around in it so it probably doesn't get enough exercise.

    In case this is what you're after:
    Engine: L77
    Mod's or standard: Stock.
    Model year: 2014
    Total km's: ~29,000
    Oil consumption: too small to measure. I.e. negligible.
    Auto or manual: Auto
    DOD present or not: Present
    DOD enabled or disabled. Enabled.
    Oil changed at ~ 4,000km / 9mth intervals (whatever the mechanic I trust uses).
     
    Last edited: Oct 24, 2019
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  10. krusing

    krusing Well-Known Member

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    I know this is a VF thread, But my L77 is the same as in a VF,
    I have a 2012 Series 2 Calais Wagon, Built July 2012, and use it as my work Car,
    Purchased it in June 2013 from a Dealer, with 16,900 k/s on the clock,
    it was ex-GM [Executive] Car that was based at Port Melbourne, was in immaculate condition,
    Ticked all the boxes at the time.
    I have never missed a service [scheduled services of 15,000k's up to 90,000 k/m's]
    Where now I have done them myself at every 10,000 k's since they charge you $100 for 7 litres of oil, and $90 p/hour.
    And they usually don't actually check/do everything on the service list.
    I did replace the DOD Filter earlier in the year as I had a noisy lifter,
    [especially when its cold, but not as notable when it gets hot, but still a little bit noisy]

    In case this is what you're after:
    Engine: L77
    Mod's or standard: Stock.
    Model year: 2012
    Total km's: ~163,000
    Oil consumption: Could be 1/2 Litre > 1 litre depends on City driving or Country Driving
    [doesn't get to the low mark between services]
    Auto or manual: Auto
    DOD present or not: Present
    DOD enabled or disabled. Enabled.
    Oil changed at ~ 10,000 k's - 5w-30 Penrite, or Shell full synthetic [what ever 5w-30 is on special at supercheap]
     
    Last edited: Oct 29, 2019
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  11. lmoengnr

    lmoengnr Well-Known Member

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    Another MY12 VE...

    Engine: L77
    Mod's or standard: Standard
    Model year: 2012
    Total km's: 91,000
    Oil consumption: Negligible
    Auto or manual: Auto
    DOD present or not: Present
    DOD enabled or disabled: Enabled
    Oil changes at 10,000km, Penrite Enviro+ GF5
     
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  12. Smashfist

    Smashfist Active Member

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    Engine: e.g. L77
    Mod's or standard: Modded. I had a lifter failure at 6,000kms from new and took the opportunity to install a VCM 714 cam, LS7 lifters, a DOD delete valley plate, pushrods to suit and Lunati dual valve springs. Something to note is that the stock rev limit is set at 6,000RPM for a reason, the DOD valvetrain carries quite a lot of weight and the collapsible lifters don't like moving quickly. Suspect mine didn't like the tune and increased rev limit so it was probably self inflicted.
    Model year: 2014
    Total km's: 20,000km now
    Oil consumption: None. I do run a heavy oil though, was recommended by my tuner to run 10w40 or 10w50 due to the high lift cam and heavy valve springs causing big pressures in the valvetrain.
    Auto or manual: Manual
    DOD present or not: Neg
    DOD enabled or disabled: N/A

    You know this guy is talking about a VZ, i.e. a 14 odd year old vehicle right?
     
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  13. CliveSS

    CliveSS New Member

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    I did replace the DOD Filter earlier in the year as I had a noisy lifter,
    [especially when its cold, but not as notable when it gets hot, but still a little bit noisy]
    DOD present or not: Present
    DOD enabled or disabled. Enabled.

    Krusing I've been trawling through some old posts and I note, from a posting you made in Feb 2019, that you were concerned with lifter noise and that you considered replacing the lifters. Did your mechanic suggest replacing the DOD filter as an alternative cure? It seems that you still have some noise but that it's not so noticeable and that it's probably acceptable - would that be correct?

    Also in your Feb 2019 post you make mention of a different cam and altered compression ratio's etc. on the AFM engine. Seems that is not widely known or understood; so hats off to you. I may be clutching at straws but do you know what DOD hardware is present in the L76 DOD factory disabled motor? Since the DOD is disabled I'm wondering if Holden used a "normal" cam? Also did they use the uprated oil pump and DOD filter?

    It seems to me that with deactivated DOD the higher flowing oil pump would cause problems associated with oil oversupply (gumming up rings etc). Similarly, cam profiles ground to allow for differing compression ratios would be unnecessary and counter productive. So to ask the above questions in a different way - does anybody know if the factory disabled DOD engine has the DOD specific uprated oil pump or the DOD specific camshaft or the DOD specific oil filter?
     
  14. CliveSS

    CliveSS New Member

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    p.s. Thanks for all replies to date. I have copied my original post to the VZ and VE forums in an effort to spread the word more widely and hopefully receive some more data relating to DOD and reliability/oil consumption issues.

    p.p.s. My posts to VZ and VE forums have been taken down. Apparently not allowed to post the same issue on multiple forums. That will probably limit the number of replies - but that's the way it is.
     
    Last edited: Oct 30, 2019
  15. krusing

    krusing Well-Known Member

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    The Lifter noise was there from about approx. 45,000k, I did mention it to The Dealer at the time,
    but they just palmed it off, saying its normal with AFM, so I didn't know anything different at the time.
    If I knew it was a common problem, I would of pushed the point, and being a ex GM vehicle,
    As mentioned, its still there, more prominent when its cold as you can hear it when you start up, and when I leave home, but doesn't take long to warm up, taking into account, I don't drive it like a grandpa, and I definitely don't thrash it, as I drive it like a V8 should be driven,
    But after its warmed up, you can just hear it.

    I did mention about compression ratio's, but I don't really know what they should be anyway,
    where I did read that the DOD pots are different to the other 4, and wouldn't change the cam or lifters other than keep it stock.
    Where I am a bit old school, and prefer to keep it stock.
     
    Last edited: Oct 29, 2019
  16. CliveSS

    CliveSS New Member

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  17. CliveSS

    CliveSS New Member

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    Summarising the responses to date:-

    1) Excessive lifter noise seems to be a problem with L76 engines whether DOD is factory disabled or not.
    2) VE series L77 engines with factory improved DOD system active - seems that roughly 50% have lifter issues and 50% are fine.
    3) VF series 1 L77 engine (with the best factory improved DOD system active) - one reported to have no issues.
    4) VF series 1 L77 engine (with the best factory improve DOD system installed but not active) - one reported lifters munched and cam lobe damage. However that was after a tune to raise the rev limit from 6000 to 6500 r.p.m.

    Please note that sample size is only six replies so I wouldn't be drawing any firm conclusions from the above. Also please note that some of the replies did not specify whether there was excessive noise or not, so difficult to make accurate analysis.

    I note that none reported excess oil consumption - so that's a good thing for any version of DOD. Also of note is that the only VF series 1 DOD (the best there is) which had problems was on a modified engine (rev. limit raised to 6500 r.p.m.)

    Could it be that VF series 1 (June 2013 - Sept 2015) L77 engines in stock form have a perfect DOD setup? Has anyone had lifter related problems with their series 1, L77, on a bog standard, unmolested, factory original motor?

    Meantime for a bit of light relief I have posted the following short video of my own clattering Thunder L76. Sounds way too noisy to me. What do you think - lifter problems?

    Any comments on it would be welcome.
     
    Last edited: Nov 2, 2019

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