What the H#$$ is that noise in my intake!
Thread Starter
Staging Lane
Joined: Oct 2006
Posts: 70
Likes: 1
What the H#$$ is that noise in my intake! Finally got my LC9 running! It idles, revs up sounds normal for 30 seconds then... Huge banging sounds come from the intake manifold area. Sounds like fire crackers going off inside. Shut it off start back up, runs perfect for another 30 seconds then fireworks again!!
I am concerned about the DOD delete situation. The company that sold me the engine said that they had removed all the pieces to delete DOD and recommended that I have the feature turned off by my programmer. I did but this noise is very scary and I don't know what else it could be. Even if it was not deleted it would not engage sitting there in park idling would it?
Any suggestions would be greatly appreciated. It's beena a long hard job getting this going and is sucks to sit here now with nothin!
I am concerned about the DOD delete situation. The company that sold me the engine said that they had removed all the pieces to delete DOD and recommended that I have the feature turned off by my programmer. I did but this noise is very scary and I don't know what else it could be. Even if it was not deleted it would not engage sitting there in park idling would it?
Any suggestions would be greatly appreciated. It's beena a long hard job getting this going and is sucks to sit here now with nothin!
If its a fresh engine the valve train can make quite a racket for the first five mins or so until everything gets pumped up full of oil. If you want to err on the side of caution then pop off your valve covers and rockers and using a syringe fill up the push rods with engine oil until they overflow then try it again. If its still noisy something else is wrong.
If you dont feel up to that then run it at a slightly higher RPM around 2K or thereabouts for a few mins and it should quiet down. If it doesnt within five mins....
If you dont feel up to that then run it at a slightly higher RPM around 2K or thereabouts for a few mins and it should quiet down. If it doesnt within five mins....
Thread Starter
Staging Lane
Joined: Oct 2006
Posts: 70
Likes: 1
The engine is new from a 2007 suburban with 9 miles on it. It runs smooth and quiet for actually about 1 minute then you can hear what sounds like a solenoid click loudly and then the clicking and banging from the intake manifold area starts. Stop the engine, re-start and it is smooth and quiet again for anther minute.
Mechanical parts don't heal. If the lifters weren't full of oil they would make noise first then quiet down after pressure arrived not the other way around.
If it was the sensors it would not run perfectly for even a minute then cause backfiring inside the intake manifold. The problem is repeatable and consistent.
Houston we have a problem.
Mechanical parts don't heal. If the lifters weren't full of oil they would make noise first then quiet down after pressure arrived not the other way around.
If it was the sensors it would not run perfectly for even a minute then cause backfiring inside the intake manifold. The problem is repeatable and consistent.
Houston we have a problem.
You have two options as I see it. Run it for five minutes as I mentioned above and see what happens or tear it down.
Theres nothing any of us can say that will magically make the noise go away. The choice is yours and I truly hope it turns out to be nothing major.
Good luck
Theres nothing any of us can say that will magically make the noise go away. The choice is yours and I truly hope it turns out to be nothing major.
Good luck
Thread Starter
Staging Lane
Joined: Oct 2006
Posts: 70
Likes: 1
Problem found and fixed!
The engine seller had removed the AFM/DOD valley cover and replaced it with a non AFM/DOD cover thinking that and deleting the feature in the PCM would delete the option. WRONG.
The blank off plate plugs the passages that would normally allow oil to flow back into the engine and after about 1 minute enough pressure is built up to collapse the lifters on the DOD cylinders. This is and the PCM program running in 8 cyl. mode still firing and injecting fuel into those cylinders with collapsed lifters caused the explosions in the intake manifold.
The key was to put back the stock AFM/DOD valley cover not plugged into anything and leave the feature deleted from the PCM is all it needed.
No Matter what you have read, Deleting AFM/DOD is as simple as unplugging it in the rear of the valley cover and deleting it from the PCM program.
The engine seller had removed the AFM/DOD valley cover and replaced it with a non AFM/DOD cover thinking that and deleting the feature in the PCM would delete the option. WRONG.
The blank off plate plugs the passages that would normally allow oil to flow back into the engine and after about 1 minute enough pressure is built up to collapse the lifters on the DOD cylinders. This is and the PCM program running in 8 cyl. mode still firing and injecting fuel into those cylinders with collapsed lifters caused the explosions in the intake manifold.
The key was to put back the stock AFM/DOD valley cover not plugged into anything and leave the feature deleted from the PCM is all it needed.
No Matter what you have read, Deleting AFM/DOD is as simple as unplugging it in the rear of the valley cover and deleting it from the PCM program.
the typical DOD delete involves removng the collapsable lifters and replacing them with regular ones. This is why I thought the noise was oil related. Fwiw you can easilly tune off the DOD without dong anything mechanical but the main issue with DOD is lifter failure. The collapsable lifters cannot deal with very high rpm or even mild cam swaps without failing so I'm assuming your cam is stock? If you search this topic out you'll find lots more info on the DOD lifters. Glad you solved the banging though
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Thread Starter
Staging Lane
Joined: Oct 2006
Posts: 70
Likes: 1
You are correct cam. My configuration is completely stock internally. I could not find any info on disabling DOD on an otherwise stock motor. All the information is available for the project if you are changing cams but I wasn't so it took a while to get a straight answer.
The power this motor exhibits with just free flowing exhaust and intake with a performance tune is astounding! I can't wait to get it out to the dunes!
The power this motor exhibits with just free flowing exhaust and intake with a performance tune is astounding! I can't wait to get it out to the dunes!
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Efficiency. Less moving parts = more bang for the buck.
Plus at some point might makes right and those dang spring lifters "apparently" dont hold up to different cam base circles/lobe designs etc.
I think DOD is marketing BS and barking completely up the wrong tree myself.
Dont be afraid of HEAT its your friend for efficiency. Just need a new special sauce LOL
Plus at some point might makes right and those dang spring lifters "apparently" dont hold up to different cam base circles/lobe designs etc.
I think DOD is marketing BS and barking completely up the wrong tree myself.
Dont be afraid of HEAT its your friend for efficiency. Just need a new special sauce LOL
Teching In
Joined: Jul 2007
Posts: 11
Likes: 0
do you know what all was "deleted" ? Do they have a rundown of what they did rather then just all was "deleted". I ask this because it sounds like it wasn't completely ... do you know what all was disabled in the programming?
