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Discussion Starter #1
Hey guys, proud new owner of ‘09 G8 GT here! Just browsing the forums, and I keep seeing guys are disabling the DOD displacement on demand cylinder deactivation, and I also see guys talking about lifter failures. I’m wondering if these are related? My engine is all stock.. am I at risk of engine damage due to DoD from normal driving (I don’t race, but I occasionally enjoy opening her up).

What is involved in performing DoD delete?
 

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F1rehawk
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Welcome to the forums. Some research would have answered all your questions.

The stock DOD lifters are weak and tend to fail/get stuck/blow up on higher mileage GTs. Most people do a DOD delete to avoid that issue. It all depends on your mileage, maintenance, etc. Some have high mileage GTs still on stock lifters without any issues.

Some vendors sell DOD delete kits, which you can research. Tons of info on this forum on how it is done. It involves swapping the lifters, cam, etc.

If you don't have any lifter noise, I would enjoy the vehicle as it is and save up to eventually perform those mods.
 

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Welcome!
Plus the car just runs better without it. And no changeover drone if you have aftermarket exhaust.
 

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Discussion Starter #5
Ok thanks guys. Yeah I searched for “DoD delete” to do some research and there were just way too many results. I just wanted to first understand the basics of why it is being done, etc. Less than 40k miles on my GT right now so I will hold off for now, learn a lot more from the forum, and go from there.
 

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Have Bar Will Travel
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I owned my car for 7 trouble free years stock and drove the snot out of it. Even raced it once. Yes raced a "just a GT" with automatic on a race course.

anyway - when I did lose a lifter it was at 166000 or so miles. and it didn't hurt anything. Now I caught it early and it threw a CEL. But I also drove on it for 3 days that way.

The DOD lifters - they are different from the other 4 - have a spring that takes up the slack when they close. So when it fails the spring basically saves the cam.


Anyway - always said when a DOD lifter went - I was doing the delete and other work. So delete and new cam went in and at over 167000 miles my car makes roughly 100 hp more than it did stock new.

The delete is fairly easy - but I also argue - unless you want more power out of it, it's not actually necessary.

I get less MPG, sure - but not drastically less.

I get a lot more midband torque. significantly so. SO there is that.
 

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OP - is it a 09, 9.1 or 9.5? Search the forum using google, If I recall correctly, later 9.5's have the revised dod lifter which are said to have lower fail rates (delphi vs Eaton). In addition, the DOD fail is not as often as everyone parrots. Search posts, you will find once taken apart, times where it was a standard lifter that failed, not DOD.
 

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Discussion Starter #8
OP - is it a 09, 9.1 or 9.5? Search the forum using google, If I recall correctly, later 9.5's have the revised dod lifter which are said to have lower fail rates (delphi vs Eaton). In addition, the DOD fail is not as often as everyone parrots. Search posts, you will find once taken apart, times where it was a standard lifter that failed, not DOD.
Good to know! I will have to see exactly what I have, when it was built, etc. I don't have Bluetooth, so I think that means it is earlier than 09.5
 

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I'm not aggressively modded, just a chip, intake and catback and I think the dod delete is overrated. I'm not sure how beneficial the mpg are, but I know it's something. I also have a corsa, so no drone and I have an 09.5.

If you're going to change cam, sure, but I'm not sure I'm all aboard the "you gotta do it" train. Keeping in mind I have a summer dd and not a track g8.
 

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The road less traveled

When my DOD lifters started making suspicious noises, I actually replaced them with DOD lifters (new style). Just for good measure, I replaced the regular lifters and the DOD solenoid valley (VLOM) plate. I did all of this since the cam was still good and I do a ton of commuting, necessitating decent gas mileage. The biggest downside to going that direction is it actually costs more than the delete so buyer beware.
 

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I owned my car for 7 trouble free years stock and drove the snot out of it. Even raced it once. Yes raced a "just a GT" with automatic on a race course.

anyway - when I did lose a lifter it was at 166000 or so miles. and it didn't hurt anything. Now I caught it early and it threw a CEL. But I also drove on it for 3 days that way.

The DOD lifters - they are different from the other 4 - have a spring that takes up the slack when they close. So when it fails the spring basically saves the cam.


Anyway - always said when a DOD lifter went - I was doing the delete and other work. So delete and new cam went in and at over 167000 miles my car makes roughly 100 hp more than it did stock new.

The delete is fairly easy - but I also argue - unless you want more power out of it, it's not actually necessary.



I get less MPG, sure - but not drastically less.

I get a lot more midband torque. significantly so. SO there is that.

Agreed.

My car had dod failure at 185k miles. Shop went in, checked things out, no debris. DoD delete kit with a new cam, LS7 lifters, BTR Valvetrain yada yada yada went in, as did a ZL1 fuel pump.
Now, with that all being said... since I didn't have the time to put in wrenching it did cost over $5,500 after it was all said and done. But I didn't want another car, or another car payment, especially on a car that I just wouldn't enjoy. So it stands now at 192000 miles 383rwhp/385rwtq and getting about 15.5/16mpg on 93 octane. Yeah, more expensive to fill and a little more often, but it is a helluva fun car and after 10 years of ownership, I really can't complain about it's dependability.
 

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Along this same line of questioning... What about a software disablement of DOD? I have done that on my 09 GT with the Diablo Sport and enjoy the lack of DOD kicking in and out. Any long term side affects?
 

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Along this same line of questioning... What about a software disablement of DOD? I have done that on my 09 GT with the Diablo Sport and enjoy the lack of DOD kicking in and out. Any long term side affects?

No side effects. I have mine disabled via tune as well. It will not extend the reliability of the lifters, but I like having it disabled.
 

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No side effects. I have mine disabled via tune as well. It will not extend the reliability of the lifters, but I like having it disabled.
why though? You're getting no reliability benefits and you're losing money on gas.
 

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F1rehawk
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why though? You're getting no reliability benefits and you're losing money on gas.
1) Because no one ever bought a V8 to drive on 4 cylinders on the highway and save gas ;)
2) Because if I recall, the DOD creates a nasty drone on an aftermarket exhaust
 

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For me, it has a noticeable vibration when it is in 4 cylinder mode and it feels like it lugs a bit before it figures out that it needs the other 4 cylinders. Seems like it just was in and out a lot. May be the geography where I live (many small hills and valleys). Now it is buttery smooth all the time. Plus, I only dropped a mpg or two. I still get well over 20 mpg on the highway and high teens in the city. Good enough for me.
 

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For me, it has a noticeable vibration when it is in 4 cylinder mode and it feels like it lugs a bit before it figures out that it needs the other 4 cylinders. Seems like it just was in and out a lot. May be the geography where I live (many small hills and valleys). Now it is buttery smooth all the time. Plus, I only dropped a mpg or two. I still get well over 20 mpg on the highway and high teens in the city. Good enough for me.

Exactly. I can sense the extreme subtle vibration that occurs when it goes to 4 cylinder mode. It even puts a resonance in the rear view mirror. Little things like that annoy me. So I disable DOD and it is smooth all the time.
 
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