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Z71Sierra15

collapsed lifter - opinions wanted

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Posted (edited)

Yes, this is my first post – as I know some of you will point out – so let’s get that out of the way.

 

I’ve been lurking around for some time, referencing different threads as things come up, but it wasn’t up until now that I needed to seek some advice from the community.

 

2 years ago I bought a used 2015 Sierra SLE Z71 (crew cab, standard bed) w/ the 5.3L V8 and 6spd automatic transmission. I recently experienced a misfire. I took it to the dealership with 61k miles on it. Initially they told me that it was a bad coil pack, but when that didn’t remedy the misfire, they suspected the injector. The injector was replaced, but the misfire remained. Next, they ran a compression test on cylinder #6. They said it had, “low compression.” Up until this point I would have been out of pocket for whatever the repair cost would have been, but since they determined it was internal and had to open it up, the factory powertrain warranty would kick in. Long story short (and not to bore you with all the details and the poor experience I had with this dealership in question), one of the AFM lifters collapsed, causing a bent pushrod. 2 weeks later (from when I dropped it off) they call me to tell me that it’s ready to be picked up. The bill was just under $5k in parts and labor (nearly 20 hours billed) – luckily, 100% of it was covered under the factory warranty.

 

So, what’s my issue?

 

They replaced all the lifters and pushrods. That’s all. And whatever else was required to complete the service (coolant, gaskets, oil, etc). But, component wise, just the lifters and the pushrods. For nearly $5k, I would have thought A LOT more would have been done than just swap the lifters and pushrods.

 

Anyway.

 

My concern is with the camshaft.

 

The lifter that collapsed had some minor scoring on the roller (pictured below - both pictures are of the same lifter, just from different angles). Is this normal wear? I inspected a lifter from a different cylinder for comparison and the roller of that lifter did not appear to have any abnormalities.

 

Common sense tells me that if there is scoring on the roller, there is probably similar marks on the surface of the cam lobe.

 

Were they taking a shortcut by not pulling the camshaft? Will this affect longevity? Can I expect premature issues down the road?

 

Or, am I overthinking this?

 

Thoughts? Opinions?

 

Has anyone else had a dreaded AFM lifter collapse and have the repair covered/performed under warranty? If so, what was replaced?

 

Thanks in advance for your time and input.

 

lifter1.jpg

 

lifter2.jpg

 

Edited by Z71Sierra15
typo

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Whoa, is this my truck? Sorry, had to do that. Very similar vehicle (2015 Sierra 1500, bought used, etc.) and very similar situation (60k miles, misfire, lifter gone bad, warranty work). I'm not nearly the gearhead you are...cams, pistons, rings, etc. I drive a truck...and that's where my experience ends. That said, I don't recall how much was done (work/cost), but the dealership had it for 5 days...it wasn't  $5K...my failing memory says it was in the $2-3K range. Anyways, I know I'm not giving you much other than telling you you're not alone. Lastly, I won't buy another GM without an extended warranty. Make no mistake, I love the vehicle, but I bought it with 22K miles and I baby the thing...on road, occasional dump runs and required service @ the point of purchase...this lifter issue isn't the only problem I've experienced with it. I've had tranny issues (warranty), the infamous headlight fiasco (solved myself), AC/radiator (warranty) and leaf springs (warranty) as well. Yep, this extended warranty has saved my butt (too) many times! No idea what the future brings. Good luck in your quest!

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Well if you've got lobe issues the engine will not run great due to a valve not properly opening and closing. Does it still have symptoms of a misfire? You can also have noticable lifter tap, a rough idle, rattling sound at higher rpm's, or the engine just feeling doggy. If you have none of that and the engine is running fine and I wouldn't worry about it. I had a lifter collapse about 10-15k miles ago and they didn't replace the camshaft because nothing looked bad. I've had trouble free miles since the repair, engine performs great.

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18 hours ago, laughey said:

Whoa, is this my truck? Sorry, had to do that. Very similar vehicle (2015 Sierra 1500, bought used, etc.) and very similar situation (60k miles, misfire, lifter gone bad, warranty work). I'm not nearly the gearhead you are...cams, pistons, rings, etc. I drive a truck...and that's where my experience ends. That said, I don't recall how much was done (work/cost), but the dealership had it for 5 days...it wasn't  $5K...my failing memory says it was in the $2-3K range. Anyways, I know I'm not giving you much other than telling you you're not alone. Lastly, I won't buy another GM without an extended warranty. Make no mistake, I love the vehicle, but I bought it with 22K miles and I baby the thing...on road, occasional dump runs and required service @ the point of purchase...this lifter issue isn't the only problem I've experienced with it. I've had tranny issues (warranty), the infamous headlight fiasco (solved myself), AC/radiator (warranty) and leaf springs (warranty) as well. Yep, this extended warranty has saved my butt (too) many times! No idea what the future brings. Good luck in your quest!

 

Like you, I’ve babied it since I bought it (with about 27k miles). I change the oil about every 6k miles (usually when the oil life indicator gets to around 25%) with Rotella Gas Truck Full Synthetic oil and WIX oil filter, so I’m certainly NOT skimping on the maintenance – some might even argue that every 6k miles with full synthetic is excessive.

 

Enlighten me on these other issues that you’ve experienced. You mentioned tranny issues, leaf springs, AC/radiator, and a headlight problem. Would you care to elaborate? I’m most interested in your transmission issues so that I can look out for any symptoms while my truck is still covered under the factory powertrain warranty.

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12 hours ago, midwestdenaliguy said:

Well if you've got lobe issues the engine will not run great due to a valve not properly opening and closing. Does it still have symptoms of a misfire? You can also have noticable lifter tap, a rough idle, rattling sound at higher rpm's, or the engine just feeling doggy. If you have none of that and the engine is running fine and I wouldn't worry about it. I had a lifter collapse about 10-15k miles ago and they didn't replace the camshaft because nothing looked bad. I've had trouble free miles since the repair, engine performs great.

 

I’ve always been a “Chevy” guy, and I love this truck, so by no means am I bashing GM. My concern here is with getting the most life out of this truck, so that I can enjoy trouble-free reliability long after I pay it off. Granted, anything mechanical will succumb to wear and tear and require occasional repairs, etc – I get that – but I just wanted to make sure that the dealership wasn’t in a rush to get the truck out of their shop or taking any shortcuts (removing and inspecting the camshaft would have required many more hours’ worth of labor). I’m ASSUMING that the tech did a thorough job and did what was needed despite misdiagnosing the coil pack… and then the injector (*eyeroll*). I’ve put less than 500 miles on it since I got it back last week and I have not experienced anything out of the ordinary. The engine appears to be running fine. In agreement with you, I would suspect any other issues would have been evident right away. I guess my main concern here is longevity or premature wear. Maybe I’m overthinking this too much, but thank you for your response.

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4 hours ago, Z71Sierra15 said:

 

I’ve always been a “Chevy” guy, and I love this truck, so by no means am I bashing GM. My concern here is with getting the most life out of this truck, so that I can enjoy trouble-free reliability long after I pay it off. Granted, anything mechanical will succumb to wear and tear and require occasional repairs, etc – I get that – but I just wanted to make sure that the dealership wasn’t in a rush to get the truck out of their shop or taking any shortcuts (removing and inspecting the camshaft would have required many more hours’ worth of labor). I’m ASSUMING that the tech did a thorough job and did what was needed despite misdiagnosing the coil pack… and then the injector (*eyeroll*). I’ve put less than 500 miles on it since I got it back last week and I have not experienced anything out of the ordinary. The engine appears to be running fine. In agreement with you, I would suspect any other issues would have been evident right away. I guess my main concern here is longevity or premature wear. Maybe I’m overthinking this too much, but thank you for your response.

Totally get it - I know you're not bashing. You've had a major issue occur prematurely, so you have every right to discuss it. I've been a loyal GM guy for years as well, and unfortunately this truck has been the most troublesome I've owned of all my GM vehicles. Now with that said, GM and my GM dealer have stepped up and made every issue right by repairing it out of their pocket - even outside of my warranty. At the end of the day I understand vehicles have a lot of moving parts that will fail eventually. It's when it's prematurely and due to design issues that GM should be making it right - and they have so far in my case. 

 

As far as longevity, it's a crap shoot. Some parts can show wear, but last forever. Others can look great, but fail. Depends on so many factors: driving habits/conditions, maintenance, etc. From your other posts it looks like you're a guy who stays on top of everything, but I have friends who are great mechanics that take care of their stuff and something breaks down regardless. For example, a buddy of mine owns a 2006 Lotus Elise that he bought a couple years ago. He's an engineer who grew up tearing apart and rebuilding all kinds of engines/motors. The Elise is wiping cams like crazy, within 2000 miles of him replacing it, and he isn't hard on the car and is proactive on all maintenance. He's gone through 4 cams and is left to the conclusion that there is something inherently wrong with the design and or build of his engine (it's actually the same engine that's in a Toyota Celica GTS believe it or not). The same goes for our lifters in these AFM engines, look at how many posts there are in this forum on that alone. Sorry, but I don't think there's a clear answer on this. I'm assuming you pulled that cam yourself and took those pics, if that's the case you've got the know-how and tools to put in a high performance cam or a new OEM cam and your worry of the scored lobes goes away. Might be your only solution if you're that worried. Just my two cents.

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Like you, I’ve babied it since I bought it (with about 27k miles). I change the oil about every 6k miles (usually when the oil life indicator gets to around 25%) with Rotella Gas Truck Full Synthetic oil and WIX oil filter, so I’m certainly NOT skimping on the maintenance – some might even argue that every 6k miles with full synthetic is excessive.

 

Enlighten me on these other issues that you’ve experienced. You mentioned tranny issues, leaf springs, AC/radiator, and a headlight problem. Would you care to elaborate? I’m most interested in your transmission issues so that I can look out for any symptoms while my truck is still covered under the factory powertrain warranty.

I forget the details (re: tranny), but when slowing down from high speed and then re-accelerating (e.g. going through a toll booth), the thing would struggle to determine if it should downshift or "stay the course", eventually leading to a hard and violent shift followed by an eventual correction. It did the same thing during colder months (from a dead stop) until it warmed up. Making things stranger is that it never did this while in the hybrid M shift/gear (set at 5 or 6 and driving it this way, accelerate, decelerate, stop, go, etc.) Anyway, they re-programmed (or adjusted) the tranny and I no longer have a hard/violent shift, but there is a more noticeable hesitation...the dealer says it's a product of the electronics (accelerator, tranny, etc.). I'm no gear-head, but it sounds like gunk to me. Still, no hard/violent shifting, so I'm good. One last thing, when I experienced this lifter issue, I did the same thing with the hybrid M shift/gear and, while the knocking remained, the major problems with hesitation (up/downshifting) were all but eliminated, yet the moment I put it back to D, the same hesitations/struggles...after a few days, I brought it to the dealer and told them to fix whatever ails this beast. Oh, during the same visit, they replaced the radiator coil (or something associated with it) due to a leak. Three months later, the AC went (there's a lot of talk about some line corroding, breaking, etc., on this site due to some nearsightedness on the design/engineering side). Initially I thought it was a bad condenser/pump, but a lot of the videos/details I found online confirmed that wasn't the case for me. When I got it back, they indicated it was caused by a leak on the line I referenced earlier. The leaf springs, come to think of it, weren't replaced because they aren't broken, just "noisy". Apparently putting mulch in the bed on a number of occasions this past spring was the reason for this - it never made such "clunking" noises while traversing potholes and bumps at low speed until after my spring cleanup chores were complete. Lastly, the headlights. If I had to knock GM for one thing, I'd say this is it. Definitely should be a recall for this, but yet it remains a TSB, for what reason I'll never know. When I inquired about this, the dealership said, "we can reprogram the BCM per the TSB, but you have to pay for it and there's no guarantee I'll achieve brighter lighting as a result". I forget the cost they quoted, but when I came back to this site, I found a better solution...even though I didn't want to go aftermarket. I went with HID (Hylux 35w ballasts and Morimoto lamps) for less than what the TSB (reprogramming and new lamps to coincide with the reprogramming) would've cost me. I chose the Hylux because it simplified the wiring and time to install stoopidly (for people like me).

 

I think that about covers it. Yep, Yolandah (that's the name I gave her) is like a girlfriend in high school...some minor quirks, but you overlook them cuz she's gorgeous. LOL.

 

Sent from my Pixel 2 XL using Tapatalk

 

 

 

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22 hours ago, midwestdenaliguy said:

Totally get it - I know you're not bashing. You've had a major issue occur prematurely, so you have every right to discuss it. I've been a loyal GM guy for years as well, and unfortunately this truck has been the most troublesome I've owned of all my GM vehicles. Now with that said, GM and my GM dealer have stepped up and made every issue right by repairing it out of their pocket - even outside of my warranty. At the end of the day I understand vehicles have a lot of moving parts that will fail eventually. It's when it's prematurely and due to design issues that GM should be making it right - and they have so far in my case. 

 

As far as longevity, it's a crap shoot. Some parts can show wear, but last forever. Others can look great, but fail. Depends on so many factors: driving habits/conditions, maintenance, etc. From your other posts it looks like you're a guy who stays on top of everything, but I have friends who are great mechanics that take care of their stuff and something breaks down regardless. For example, a buddy of mine owns a 2006 Lotus Elise that he bought a couple years ago. He's an engineer who grew up tearing apart and rebuilding all kinds of engines/motors. The Elise is wiping cams like crazy, within 2000 miles of him replacing it, and he isn't hard on the car and is proactive on all maintenance. He's gone through 4 cams and is left to the conclusion that there is something inherently wrong with the design and or build of his engine (it's actually the same engine that's in a Toyota Celica GTS believe it or not). The same goes for our lifters in these AFM engines, look at how many posts there are in this forum on that alone. Sorry, but I don't think there's a clear answer on this. I'm assuming you pulled that cam yourself and took those pics, if that's the case you've got the know-how and tools to put in a high performance cam or a new OEM cam and your worry of the scored lobes goes away. Might be your only solution if you're that worried. Just my two cents.

 

I didn't pull the cam, but I did take pictures of the collapsed lifter that the dealership replaced. I was more so just speculating that if the roller was scored then the cam lobe probably has similar marks as well.

 

I do agree with you in that there's no real way to know. Maybe an issue arises 2k miles from now, or maybe I get another 200k miles out of it before I experience another problem like this. I guess all I can do is stay on top of maintenance and hope for the best.

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22 hours ago, laughey said:

I forget the details (re: tranny), but when slowing down from high speed and then re-accelerating (e.g. going through a toll booth), the thing would struggle to determine if it should downshift or "stay the course", eventually leading to a hard and violent shift followed by an eventual correction. It did the same thing during colder months (from a dead stop) until it warmed up. Making things stranger is that it never did this while in the hybrid M shift/gear (set at 5 or 6 and driving it this way, accelerate, decelerate, stop, go, etc.) Anyway, they re-programmed (or adjusted) the tranny and I no longer have a hard/violent shift, but there is a more noticeable hesitation...the dealer says it's a product of the electronics (accelerator, tranny, etc.). I'm no gear-head, but it sounds like gunk to me. Still, no hard/violent shifting, so I'm good. One last thing, when I experienced this lifter issue, I did the same thing with the hybrid M shift/gear and, while the knocking remained, the major problems with hesitation (up/downshifting) were all but eliminated, yet the moment I put it back to D, the same hesitations/struggles...after a few days, I brought it to the dealer and told them to fix whatever ails this beast. Oh, during the same visit, they replaced the radiator coil (or something associated with it) due to a leak. Three months later, the AC went (there's a lot of talk about some line corroding, breaking, etc., on this site due to some nearsightedness on the design/engineering side). Initially I thought it was a bad condenser/pump, but a lot of the videos/details I found online confirmed that wasn't the case for me. When I got it back, they indicated it was caused by a leak on the line I referenced earlier. The leaf springs, come to think of it, weren't replaced because they aren't broken, just "noisy". Apparently putting mulch in the bed on a number of occasions this past spring was the reason for this - it never made such "clunking" noises while traversing potholes and bumps at low speed until after my spring cleanup chores were complete. Lastly, the headlights. If I had to knock GM for one thing, I'd say this is it. Definitely should be a recall for this, but yet it remains a TSB, for what reason I'll never know. When I inquired about this, the dealership said, "we can reprogram the BCM per the TSB, but you have to pay for it and there's no guarantee I'll achieve brighter lighting as a result". I forget the cost they quoted, but when I came back to this site, I found a better solution...even though I didn't want to go aftermarket. I went with HID (Hylux 35w ballasts and Morimoto lamps) for less than what the TSB (reprogramming and new lamps to coincide with the reprogramming) would've cost me. I chose the Hylux because it simplified the wiring and time to install stoopidly (for people like me).

 

I think that about covers it. Yep, Yolandah (that's the name I gave her) is like a girlfriend in high school...some minor quirks, but you overlook them cuz she's gorgeous. LOL.

 

Sent from my Pixel 2 XL using Tapatalk

 

 

 

 

Wow.

 

My main concern is with the transmission.

 

Aside from AFM lifters failing, transmission issues seem to be another popular topic here.

 

I can relate with some of what you described. I notice hesitation at times - almost as if it wants to downshift but then doesn't. Maybe I need to be more aggressive with he accelerator. haha

 

All joking aside, my truck seems to be way more responsive when I keep it in M5. As I understand it, "manual mode" deactivates the AFM system, so maybe that is part of the problem (?).

 

Regardless, I think it comes down to programming. When in drive, it seems like it hesitates a lot more than it should, then when it finally does shift, it can be very sudden and rather rough.

 

Recently, I have experienced violent downshifts when coming to a stop. It did it on 2 separate occasions. Turning the truck off and then restarting it has remedied this issue, but what the heck is going on?!

 

And, of course, I've had my truck in for other things (inspection, recalls, etc.), and every time, I mention the hesitation and clunks and rough downshifts, but the tech that drives it "was not able to replicate" these symptoms.

 

They did offer to have a tech ride with me on a test drive, but I haven't really been able to get it to do it on demand - it seems to be random.

 

Thoughts?

 

 

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20 minutes ago, Z71Sierra15 said:

 

Wow.

 

My main concern is with the transmission.

 

Aside from AFM lifters failing, transmission issues seem to be another popular topic here.

 

I can relate with some of what you described. I notice hesitation at times - almost as if it wants to downshift but then doesn't. Maybe I need to be more aggressive with he accelerator. haha

 

All joking aside, my truck seems to be way more responsive when I keep it in M5. As I understand it, "manual mode" deactivates the AFM system, so maybe that is part of the problem (?).

 

Regardless, I think it comes down to programming. When in drive, it seems like it hesitates a lot more than it should, then when it finally does shift, it can be very sudden and rather rough.

 

Recently, I have experienced violent downshifts when coming to a stop. It did it on 2 separate occasions. Turning the truck off and then restarting it has remedied this issue, but what the heck is going on?!

 

And, of course, I've had my truck in for other things (inspection, recalls, etc.), and every time, I mention the hesitation and clunks and rough downshifts, but the tech that drives it "was not able to replicate" these symptoms.

 

They did offer to have a tech ride with me on a test drive, but I haven't really been able to get it to do it on demand - it seems to be random.

 

Thoughts?

 

 

Popular, yeah, that's one way of looking at it. LOL

 

I concur -- find myself slipping into M5/M6 if the hesitation rears its ugly head.

 

We must have the same dealership -- I got/get the same runaround every time...especially the one about being more aggressive with the gas (the "lead" mechanic said this to me, no joke). Being that I work in the IT field, I'm far too understanding of the ole, "was not able to replicate" comment. I can't count how many times colleagues have said "this doesn't work" or "that's making a noise" and I investigate and can't get it to repeat what they say it's (not) doing. Oftentimes, it does end up being discovered/confirmed, but not without some deep-dive investigating or time/energy dedicated to it...just like technology, it's not like people can just leave said property for infinite amounts of time in hopes of rectifying a certain issue/problem, especially when it's not happening on a daily basis.

 

Another thing all of this dialog has has brought forward was another "nuisance" issue I've experienced (that the dealership could never resolve)...this only happens in the winter months (very cold as in near zero), but at least a dozen times over the past two winters, I get in the vehicle (after it sits overnight), start it up and NO audio of any kind...no belt-minder, no door open, no star-up dinging, no stereo, no bluetooth and no blinker ticking). Absolute silence. And whatever the name of the white/background noise canceling technology is that GM "pumps" into the cabin to decrease the all-mighty rumble of the road (noise) is also unavailable (much louder on the highway). If I turn the vehicle off immediately, the problem usually remains upon restart. If I wait awhile, hit or miss, it comes back to normal. Initially I believed it may have to do with the vehicle needing to warm up, but there's just no way that is (can be) accurate...sometimes it takes longer whereas other times it takes multiple attempts, regardless of time. A couple of times I gave up, only to have things "back to normal" the next day.

 

In the end, there doesn't seem to be any real resolution to this floppy transmission issue - at least not from the manufacturer...as if they (or any organization) would acknowledge it anyways. Sadly, this position leaves a bad taste in the mouths of those affected and, as a result of this ignorance, insurance/warranty "businesses" are making a killing in our liability-filled indemnifying society. Capitalism at its finest right t/here!

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On the marked roller and mating surface of the camshaft... I recommend that you install a drain plug with a good magnet. If the hardened surface of the cam starts to fail on that lobe.. some of the remnants will end up on your magnet. Each time you drain, you will be able to see if any of the iron hardened parts are starting to shell.. You can get fancy and weigh it after each change and track it. In my experience, though, you will look at it and know when something is flying apart inside.

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23 hours ago, laughey said:

Popular, yeah, that's one way of looking at it. LOL

 

I concur -- find myself slipping into M5/M6 if the hesitation rears its ugly head.

 

We must have the same dealership -- I got/get the same runaround every time...especially the one about being more aggressive with the gas (the "lead" mechanic said this to me, no joke). Being that I work in the IT field, I'm far too understanding of the ole, "was not able to replicate" comment. I can't count how many times colleagues have said "this doesn't work" or "that's making a noise" and I investigate and can't get it to repeat what they say it's (not) doing. Oftentimes, it does end up being discovered/confirmed, but not without some deep-dive investigating or time/energy dedicated to it...just like technology, it's not like people can just leave said property for infinite amounts of time in hopes of rectifying a certain issue/problem, especially when it's not happening on a daily basis.

 

Another thing all of this dialog has has brought forward was another "nuisance" issue I've experienced (that the dealership could never resolve)...this only happens in the winter months (very cold as in near zero), but at least a dozen times over the past two winters, I get in the vehicle (after it sits overnight), start it up and NO audio of any kind...no belt-minder, no door open, no star-up dinging, no stereo, no bluetooth and no blinker ticking). Absolute silence. And whatever the name of the white/background noise canceling technology is that GM "pumps" into the cabin to decrease the all-mighty rumble of the road (noise) is also unavailable (much louder on the highway). If I turn the vehicle off immediately, the problem usually remains upon restart. If I wait awhile, hit or miss, it comes back to normal. Initially I believed it may have to do with the vehicle needing to warm up, but there's just no way that is (can be) accurate...sometimes it takes longer whereas other times it takes multiple attempts, regardless of time. A couple of times I gave up, only to have things "back to normal" the next day.

 

In the end, there doesn't seem to be any real resolution to this floppy transmission issue - at least not from the manufacturer...as if they (or any organization) would acknowledge it anyways. Sadly, this position leaves a bad taste in the mouths of those affected and, as a result of this ignorance, insurance/warranty "businesses" are making a killing in our liability-filled indemnifying society. Capitalism at its finest right t/here!

 

I actually experienced that last winter - and I thought I was crazy!

 

It "fixed" itself when I went to leave work, but the drive in? No key in the ignition with the door open chime, no turn signal clicking, etc.

 

It was bizarre.

 

I figured it was a fluke.

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22 hours ago, PPK said:

On the marked roller and mating surface of the camshaft... I recommend that you install a drain plug with a good magnet. If the hardened surface of the cam starts to fail on that lobe.. some of the remnants will end up on your magnet. Each time you drain, you will be able to see if any of the iron hardened parts are starting to shell.. You can get fancy and weigh it after each change and track it. In my experience, though, you will look at it and know when something is flying apart inside.

 

That's a good idea.

 

Thanks for weighing in on this.

 

I think I'll just have to keep a close eye on things for awhile.

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I didn't read through all the post but do you have HPtuner?

 

My cam and lifters where scored just like yours.  So I did a cam swap and DOD delete so I don't have to worry about it happening again.  And if I did all this work myself I don't have time to do it twice.

 

But before I did the swap I knew I had a problem because I could log with my HPtuner.  I saw that as soon as I got into the throttle semi hard and the RPMs got up to 2,000 or so.  It would peg out the Knock sensor with 12 or 13 degrees of timing being pulled and I had no power.  Before I ever had this problem, I had 0 knock or very very little. 

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Also I you wanted to go through my cam swap thread on performancetrucks.net you can go to page 7 and 8 I think it is and see what my lifters look like and what the cam looks like.  My lifters looked worse than the cam but the cam still had some scoring on certain lobes.

 

https://www.performancetrucks.net/forums/gmt-k2xx-trucks-general-discussion-221/first-ever-cam-swap-l86-will-take-any-advice-555280/

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