I just recently (4 days ago) did a dod/afm delete on my 5.3. It has 176k on the motor and it never had any issues until one day a few weeks ago it suddenly started misfiring. I pulled over asap and went to a shop. They told me that it sounded like a stuck lifter. After a mere minutes, the misfire went away. No more nothing. Back to being quiet as a mouse. It really freaked out and confused the techs. The techs said that it would be better to be safe than sorry and do a DOD/AFM delete before anything catastrophic happened. No problem doing, my buddy and I spent a day doing it and got it running. We used an AMS racing DOD/AFM delete kit and used AMS racing .560 valve springs. I used a a stock style cam, just meant for the delete. Before any of this the motor was quiet as could be. Surprising for a 5.3 with 176k. Now after the delete, it makes a ticking noise, constantly. The tick increases in speed under acceleration, and ticks at idle, something it never did before the delete. The lifters came presoaked and specifically said not to soak before installation, which was odd to me since i know its a common practice to soak the lifters before installing. New parts I installed include the delete kit, valve springs, spark plugs and wires (since they've never been changed), and I ended up buying a driver side exhaust manifold and installed a new driver exhaust manifold gasket and flange gasket. Any ideas as to how to source the new found tick or quiet it down at least? Its not MY daily, so I hear all about it from her when she drives it and how she misses how quiet it used to be.
DOD Delete now ticking
- Thread starter Hank_M
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Do you have a video of the current noise? You can upload to YouTube with public permissions and link it back here. That would help us a lot.
Did you use a pushrod length checker to make sure yours were right for that cam? Also, specifically which cam and lifters did you use? AMS offers several options with their kits.
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donjetman
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lifter preload could be incorrect because pushrod length is now incorrect.
Here's a video on how to check/set lifter preload:
Here's a video on how to check/set lifter preload:
I'll add that if the cam specs vary much from stock, then added valvetrain noise is to be expected and can usually be quieted significantly by carefully choosing the correct pushrods for each lifter through careful measurements and preload adjustments. I've also seen cam grinds that had minor surface imperfections that then made noise once installed.
But if it's a rhythmic loud ticking or chirping sound that seems to be at half crankshaft rotation speed (one tick for every two rotations of the crankshaft), then something else is wrong. The most likely culprits in that case are (in order of probability): 1/ Slightly bent pushrod that was reused and shouldn't have been. 2/ A defective lifter 3/ A poor quality aftermarket lifter tray that's letting a lifter twist slightly on the cam 4/ Loose rocker arm pivot bearing.
But if it's a rhythmic loud ticking or chirping sound that seems to be at half crankshaft rotation speed (one tick for every two rotations of the crankshaft), then something else is wrong. The most likely culprits in that case are (in order of probability): 1/ Slightly bent pushrod that was reused and shouldn't have been. 2/ A defective lifter 3/ A poor quality aftermarket lifter tray that's letting a lifter twist slightly on the cam 4/ Loose rocker arm pivot bearing.
This is the DOD/AFM kit I used. https://www.amsracing.net/products/...-gasket-set-bolts-lifters?variant=42721425614
I did not check my pushrods and should've checked all my pushrods and various other things, but I was in a rush and I really wanted to get it done. I'll have a sound update tomorrow morning when I start it. I'm really banking on something being wrong with the valve train. I am really not interested in pulling the heads again, but if it's a new lifters that's causing the noise, then maybe I'll have to.
I did not check my pushrods and should've checked all my pushrods and various other things, but I was in a rush and I really wanted to get it done. I'll have a sound update tomorrow morning when I start it. I'm really banking on something being wrong with the valve train. I am really not interested in pulling the heads again, but if it's a new lifters that's causing the noise, then maybe I'll have to.
Okay, so it looks like that's the LM7 cam. If it's indeed a genuine GM part, then your original pushrods should have been fine as long as they were straight. And it looks like the default lifter selection is "LS7 style" but they don't list the manufacturer of the lifters, which is concerning. But, given that a set of Chevrolet Performance lifters runs about 2/3 the price of that kit, my guess is they're aftermarket. That said, Melling makes some of the aftermarket lifters and they're also the OEM lifter supplier to GM, so they could be legit quality also. There's just no way to know.
Anyway, please do post the video when you can and we'll likely be able to tell you what's happening. Fingers crossed.
I didn't see where you replaced the oil pump? One of the first things to check when you hear that ticking is your oil pressure. Any sign of low oil pressure?
With that said.... And if oil pressure is not an issue, and the description of what was done and with what hardware.... The first thing I would do is check your lifter preload and question the used push rods. While you're at it, closely inspect your trunion bearings. At your mileage, I would have replaced the trunnion bearings and the push runs, not to mention the oil pump and timing chain set. If the above checkout, I'd be pulling the heads and replacing the lifters with real LS7 lifters. They are identified by the gold clip in the end of the lifter that retains it. An absolutely no lifter trees other than GM genuine.
If your oil pressure is questionable from the previous check, you'll need to pull the cam and inspect the cam bearings. I picked up a fiber optic camera with like a 3-foot lead for under $100 several years ago. Works fantastic, you hold it and look at the screen while you guide the camera through the camshaft bearings. But if your oil pressure is good, I would disregard this paragraph.
The only other possibility that comes to mind, is a worn out lifter bore. Which could have been the cause of the original noise and the AFM delete kit would not address that. Well sometimes that could be found with a visual inspection like with the above fiber optic camera setup, measuring with a bore gauge is the way to go if no visible damage is seen.
With that said.... And if oil pressure is not an issue, and the description of what was done and with what hardware.... The first thing I would do is check your lifter preload and question the used push rods. While you're at it, closely inspect your trunion bearings. At your mileage, I would have replaced the trunnion bearings and the push runs, not to mention the oil pump and timing chain set. If the above checkout, I'd be pulling the heads and replacing the lifters with real LS7 lifters. They are identified by the gold clip in the end of the lifter that retains it. An absolutely no lifter trees other than GM genuine.
If your oil pressure is questionable from the previous check, you'll need to pull the cam and inspect the cam bearings. I picked up a fiber optic camera with like a 3-foot lead for under $100 several years ago. Works fantastic, you hold it and look at the screen while you guide the camera through the camshaft bearings. But if your oil pressure is good, I would disregard this paragraph.
The only other possibility that comes to mind, is a worn out lifter bore. Which could have been the cause of the original noise and the AFM delete kit would not address that. Well sometimes that could be found with a visual inspection like with the above fiber optic camera setup, measuring with a bore gauge is the way to go if no visible damage is seen.
I think this is the issue. not oem or millings lifters used. it seems common and I don't blame anyone. a lifter isn't a really special part. seems like any old lifter was fine before but now days not so much. didn't we just have a post of a guy that used a Amazon kit and it wouldn't run right? he didn't seem to want to go into details thou.
hopefully if it is a aftermarket lifter, it's more that the length isn't right more than you have to pull the head again.
Little update. Didn't get a good chance to make a video for the tick noise. However, I did discover that it doesn't make the tick while idling, and it doesn't do it when the vehicle is revved and stationary. It makes the noise only when giving the vehicle gas, and moving. So the noise stems from something that reacts while under load. Could be a cam bearing where I installed a new cam and I should've addressed this earlier, but the bearings did look thin when I inspected them during the delete process. Figured I would "go for it" and see where it lands me. So I will take a video tomorrow when I drive the vehicle to work.
I installed a new oil pressure switch before all this happened, and that same day I installed it, was the day that the sudden misfire happened that I mentioned earlier in the thread. After the delete, Oil pressure is perfect, the vehicle performs well (aside from the tick ofcourse). I did not replace the oil pump either. I plan on checking the lifter preload tomorrow as well. The goal with tomorrow is to pull the valve covers one side at a time, check all rocker arms, pushrods, and use a scope to inspect all of the lifters, camshaft, and cam bearings if able and time allows it. I'm also going to sextuple check the exhaust manifold bolts. (I've had the driver side out so many times trying to get the new one installed, but that's neither here nor there)
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