My truck:

2008 GMC Sierra LC9 AFM Flex Fuel 5.3l

Well, hate to beat a dead horse. But i'm also suffering what i'm thinking is the onset or just start of lifter tap. Oil pressure is fine, and haven't thrown a code but i can definitely here it. Very profound and gets louder after a long highway drive. When i discovered this i checked the oil, and the dip stick was dry. Took 2 quarts to get it back mid range.

Here is the kicker... I bought the truck 4 days ago... It only had 65k miles. I bought it from a broker who was selling for an old man who basically treated it as a "when you needed it" vehicle. The broker is a service manager at a local family owned tire and lube auto shop, three family generation blah blah. He was selling the truck for a long standing customer that had all its service work done there since brand new. He had every 15k mile major service done, but his oil changes were infrequent and would wait 7k miles before an oil change, or he would wait 3k miles but it would have been a year and 6 months since the last. My ignorance made me neglect checking it's service history any further. I didn't think to look at the intervals, i just looked at what was done on the documentation. But i drove the truck and checked all the generic things... seemed pretty "A Ok". But didn't think to try and listen hard from a stand still to check for potential lifter tap. Road noise and aftermarket exhaust kind of blocked out the sound. Only way i heard it was with window down and accelerating up to 4k rpm moving from a complete stand still. Heard the profound "tap tap tap tap" speed up and get louder with rpm... then die back down...

Well where i'm at now... researching like a SOB... because only those i can trust is really others who have dealt with the problem... This thread by far is the best so far on the issue. I went to a local performance shop that builds and deals primarily with LSX variants. He said to do the very same thing you guys are doing in this thread. So it's starting to look more and more like the solution. But not one i'm comfortable with since i already spent cash on what i thought was a problem free truck at least for another 60k miles, boy was i wrong. He recommended going with LS7 lifters, BTR head bolt kit, BTR stage 1 truck cam kit with gm performance springs (since it'll be easier to change at that point dissambled) and last but not least the DOD AFM delete...

But the last thing that's got me nervous is the possibility of gunky piston rings... I mean i feel like this whole engine would need to be gone through just to ensure my better comfort and to make sure that its not totally at the cusp of more issues. In the end, i should just go crate engine... but then that just comes back full circle with the money situation... sounds like a lose-lose situation to me.

Like always, i never know what's worth doing... I'll update on what i do... as of now truck is parked and i'm driving my beater a 90 volvo 240.

Is anyone in here in Charleston, SC and feel like helping me deep dive this? I'd provide a case of beer every weekend for a year haha.

 

It was a collapsed lifter. #7 intake. I don't know if anyone has ever tried to just get a longer pushrod and place it in the lifter that collapsed? In theory it should work. I don't know if you need some of the"hydraulic" to keep the valve adjusted? But it definitely would be an easier option.

 

Seems like just fixing the one lifter may only get you by since with cases like this while having everything opened up to you have the "might as well" replace all lifters. I guess my feeling is trying to fix and keep using the DOD AFM, because in the truck, because people seem to just think it is a joke. Everyone seems to just toss it to the side. I really just want to fix and tune it out but not sure if that would be any different. Or if I'm just going to see the problem again with another DOD AFM lifter. I actually slept on it and feel a little better about doing the semi top end build with the cam. I think as a start just want to drop the pan and open up the valve covers, inspect and just decide from there. If the engine doesn't look noticeably gunky I'll just fix the lifter and try and do a some flush remedies and carefully get the truck transitioned to synthetic.


Also, it's not the parts that's killing me... its the labor. If i had a garage and the room, despite not having much engine build experience. With this not being my only vehicle i'd do a lot of this myself. cam kit with springs, push rods, afm delete are really just under 1k... that's not bad for a semi budget upper build...

 

I have a 07 burb that has a lifter failing, it works fine until dod activates. When dod deactivates the lifter will not relatch until you shut off the engine and let it sit for a few mins, start and works fine again. Can I get by with just programming out the dod? Will probably try it and see what happens.

 

Well guys, i was way off!

Went to the dealer and well... they suspect rod knock... So with only having the truck 5 days... i rolled right back to the broker who sold it to me (he works for a auto shop and in actuality is represented by the shop since on this purchase i made the check out to the shop) and they said they are going to take a look. I didn't tell them i had already went to GMC/GM because i'm trying to give them the chance to make it right, but if they try and deny or say it's not their problem then i will start taking to more tough matters. But as of now it's all been civil and cordial, hopefully they'll make it right. But as of now me and dealership have strong beliefs the engine is going to have to be replaced, because they don't typically like to fix rod knock. Since this is the onset could be better and more preventative to just replace with a new motor with a warranty/guarantee...

They also told me since the truck isn't that old and doesn't have a lot of miles and is only two years out of warranty, GM corp. may offer assistance. Apparently they do it often, question is how much. So i may combine what the expense of what the original broker might do with the assistance from GM to just get a whole new motor...

It's going to be a long week. Although the broker said the shop we'll look at it, nothing is evident yet that they will offer to do anything... All i have is my patience right now.

2008 GMC Sierra SLT Z71 w/ 65k miles

 

I had a similar issue with my 08 suburban 124,000 miles. Driving down the freeway all of a sudden the engine light started blinking as well as the service stabilitrac light. Engine started running rough. Checked codes and it showed #6 cylinder misfire. I changed the spark plug, wire, fuel injector and swapped coil pack with #1 cylinder but still same issue. I put it in a local shop hoping it was a sensor. The shop told me that the cylinder did not have compression and recommended that I buy a new engine. I had my brother-in-law check it out since he is a mechanic. He found that it was a bad lifter. All in all the parts cost me about $500 and the vehicle drives great.

 

Any updates? Just curious on what the broker found.

 

I just did my dod delete ,now I need to get a programmer and tune it out from the computer, was just wondering what does the dod have to do with the stabilitrack that keeps popping up? I've read on here others having it pop up when they start having issues from the dod.

 

rhino200099 and deuce189, I had the exact thing happen to me Deuce, minus the rod knock....I bought my 2011 with 57k on it checked it over and did all the research I could and I knew about the oil consumption issues with all LS motors after 2006 along with other the typical LS "characteristics" anyways I noticed I had small amount of oil consumption happening not as bad as Ive read on here or the web....I am OCD like a **** and talked with several LS companies ( Tick, Texas Speed and BTR) I decided to just go ahead and get the DoD turned off.

So I took it to Steve at Tuned by Frost and tried that first, well it didn't satisfy me....so I ordered the DoD and VVT delete kit along with BTR stage 2 cam and spring combo. I tore it down and had the heads cleaned and new seals put in along with the valves checked and lapped. Installed K&N intake, MagnaFlo exhaust and installed a oil catch can just for good measure and then took to Steve for a full tune.....

Netted a 300hp and 315 lbs torque which I'm extremely happy with! The truck runs like it should've from the factory. Makes 250lbs tq off of idle!

Anyways thought Id give my .02 cent for what its worth I am typing this as I complete my first 3k oil change since the install and delete and no issues what so ever, other than a little valve train noise due to the cam and springs.

 

Just did a DoD Delete on my 2009 5.3L Silverado. After 2 different times the DoD lifters collapsing. The first time at 80,000 miles and the second at 120,000. I purchased a DoD delete kit for Brian Tooley Racing and a Stage 1 truck cam and springs for about $1000.00. Also replaced all the valve stem seals.
You will need someone to turn the DoD off in the computer. The truck runs better than new and I see no more smoke coming out of the exhaust any longer.
I also hope this takes care of the oil consumpsion.
This Fuel management system is junk

 

This is the first LS swap I am having done to my '97 Silverado, and I am interested in wanting to know what is the big deal with deleting the DOD? The technology I have read for it being in the engines would definitely fit my traveling needs. So if I am missing something please someone tell me before I do this cam upgrade in which I plan to keep the DOD entacked. Thanks BillyMac.

 

Hello Billy I purchased this 2009 Silverado Z71 new and twice the DOD lifters failed. The spring on them collapses and they get stuck then the engine will knock like crazy. This Fuel management system is junk.
My truck runs stronger and the fuel millage is better than before plus I have a piece of mind that will not happen again.
Also put true duel exhaust and K&N cold air system with the new .530 lift cam the truck screams now.
This truck is a every day driver.
Delete it you will not be sorry.

 

Attached is a photo of the DOD lifters that were in the #1 cylinder as you can see one of them is collapsed.

 

Looking to do or have done.
Enging is sounds as if it is clapping. Looks as though a lifter is collapsed or maybe one of the solenoid's in the VLOM. Has gone bad.
as most of us on a tight buget.
Might you have any thoughts?
Read that your shop does the needed repair regularly.
Where might you be located as I am in San Antonio, Tx
Thanks for your time.

 

I currently have a 2009 Silverado with a 5.3 with Vin code J I guess that makes it an Ly6. I have been researching various different models of cams and see the single bolt and 3 bolt cams. Does anyone have a mutual consensus of best basic cam and lifters said to use for an AFM delete? I'd appreciate any advice because I only want to do this one time through thank you

 

I have an 08 5.3 lc9. Its the dod/afm motor. I lost oil pressure and started this journey to fix my motor. After new o ring on pic up tube and new oil pump I'm still not getting any oil to the top of the motor. NOT A DROP coming up and put the push-rods. The only other problem I can think of is a clogged screen on the oil pick up. My question is would a clogged screen make it read zero pressure? I would think I would get some type of reading but I'm getting nothing. My only other option is a new/rebuilt motor at this point. I'm still paying on the vehicle so it's a "must fix" problem

 

Have you cleaned or replaced the little screen/filter (PN 12585328) under the Oil Pressure Sender? If I understand the oil flow path, I think the screen below the OP Sender is before the sensor and before the AFM Solenoids. You could have full oil pressure to the bearings etc, but none to the AFM Solenoids and 0 on gauge, if the screen is totally plugged.

 

I checked the screen when I replaced the sencor and it was spotless. So I'm still not sure why I'm not getting oil. I don't think my oil is even making it up to the screen. I thought a new oil pump and o ring would be my fix but still nothing. Only thing left is a clogged screen or possibly a spun cam bearing blocking the rear main oil journal.

 

Well there is an AFM Relief Valve in the pan that could be stuck open???

 

Fwiw if you are doing the afm delete you will want to address a few things. Use the l92 valley cover on. Its not expensive and good insurance. Also make sure id your oil pump is vane style to swap it out for a reg georotor style like the reg ls6 pump.

We have dod lifters avail in sets of 4 for WAY cheaper than gm also. IF you are going to keep them.

We also have a hi flo oil pump that is better than the ls6 for less $$ as well.

For reference the l92 valley cover (complete with gaskets, o rings, and bolts) runs about $50. Gets rid of the screen and all the leaky/clogged solenoid bs and you wont have to worry about them. i actually like to go a step further and plug the towers just in case.