Generation IV Internal Engine - DOD, VVT and AFM Proper Removal Questions - Popping Back Through Intake Issue

Hey All,

I have a customer with an issue I had not run into before nor tried to do. The engine I believe is a 2008 G8 Auto engine with both DOD and VVT. They removed the VVT with the proper cam gear and cover and they also replaced the DOD valley cover with an LS3 unit. It still has the stock DOD lifters.

The engine controller and harness is a GMPP LS376/480 package and the enigine is in a 2nd Gen TA with an M5 and otherwise standard setup.

What happens is that after inital start up, she runs fine for 10-15 seconds, then starts banging back through the intake very hard. If you had the hood closed you would swear a couple connecting rods were getting ready to exit the block.

Shut her off and set for a minute, restart and the same runs good for 10-15 seconds then bang, bang, bang.

What I am looking for besides what could be going on is what folks have done with a VVT and DOD engine to make it a "standard" engine. My thought in this case is the stock DOD lifters need to be chenged to standard units. I hate to tell them this, make that change and still have the issue.

Good oil pressure and actually idles decnt for the time it is running.

Any help is greatly appreciated for sure.

Mike Norris

Aren't DOD lifters a different style lifter????

Here is a good post on this subject.
http://www.ls1tech.com/forums/generation-iv-internal-engine/1133386-disable-dod.html

Thanks for the info guys.

Mike Norris

Thanks for all the input and the lifters fixed it. I had an initial feeling it was lifters, but when talking to MAST and Livernois, Since they sell VVT conversions and VVT crate engines, they said that they run the DOD lifters with no problems. So I figured it was good to ask elsewhere.

The stock DOD oil pump is still in there and it has good to crazy oil pressure so I think changing it out to a standard unit would be a good idea also, but at least it is not causing issues now.

Thanks again.

Mike Norris

Our DOD Delete Kit includes non-DOD lifters and lifter buckets. We never run the DOD lifters with a non-DOD cam.

Regards,

Rick LeBlanc
Livernois Motorsports

Hi Rick,

Thanks for chiming in. I remember seeing the kit with the lifters, but when the customer called and talked to a salesman there, they told him that it was not a necessity and the lifters could be deleted from the kit if he wanted.

Thanks for clearing that up.

Mike Norris

Hi Rick,

Thanks for chiming in. I remember seeing the kit with the lifters, but when the customer called and talked to a salesman there, they told him that it was not a necessity and the lifters could be deleted from the kit if he wanted.

Thanks for clearing that up.

Mike Norris


Mike,

I apologize, I'll go talk to the sales guys just to be sure they are aware.

Glad you figured out the issue though.

-Rick