Rattle/grinding noise at 25-35 mph, mechanic told me AFM and lifters need to be changed.

[Dustin Jackson]

@iboughtatahoe23 I see. Well at least our test was successful, pick your preferred way of disabling AFM and proceed

 

[iboughtatahoe23]

Can anyone tell me if it is safe to drive in M? Like in 5th all the time?

 

[wjburken]

Personally, I think your situation is more of a now thing instead of a later thing. From what you are describing, you very likely have compromised lifters and the longer you run them, whether they are making noise or not, the greater the risk that you will have a catastrophic failure of a lifter which can take out your cam completely and send metal through your motor.

 

[iboughtatahoe23]

I also hear a light tap on the right side wheel well area. Thought it was exhaust leak but it’s on the complete opposite side of the broken stud

Pop says “sounds like a normal lifter going up and down”

 

[iboughtatahoe23]

Personally, I think your situation is more of a now thing instead of a later thing. From what you are describing, you very likely have compromised lifters and the longer you run them, whether they are making noise or not, the greater the risk that you will have a catastrophic failure of a lifter which can take out your cam completely and send metal through your motor.

Then drop a crate motor in and we good.

 

[iboughtatahoe23]

Personally, I think your situation is more of a now thing instead of a later thing. From what you are describing, you very likely have compromised lifters and the longer you run them, whether they are making noise or not, the greater the risk that you will have a catastrophic failure of a lifter which can take out your cam completely and send metal through your motor.

I hear you man, but it’s tough bc I have this on a loan and don’t wanna throw money at it if I don’t know 100% that it’s the lifters

 

[iboughtatahoe23]

@iboughtatahoe23 I've heard good things about this guy, this will be cheapest option in tuning AFM out: https://lt1swap.com/afm_delete.htm

Seems kinda inconvenient I’d be out of a car for a few weeks, got a job to get to that’s miles away so not sure how that would work. Might just buy that range AFM disabler and call it a day

 

[iboughtatahoe23]

Personally, I think your situation is more of a now thing instead of a later thing. From what you are describing, you very likely have compromised lifters and the longer you run them, whether they are making noise or not, the greater the risk that you will have a catastrophic failure of a lifter which can take out your cam completely and send metal through your motor.

Also not experiencing any lifter failure symptoms I don’t think… what are the symptoms?

 

[tom3]

On our Tahoe putting the shifter in M and selecting the 6th top gear also reverts to normal operation with the V4 and V8 mode. I notice ours does vibrate a bit in V4 mode with a bit of a load just before it switches to V8. I'd love this system - if it was more reliable.

 

[wjburken]

Also not experiencing any lifter failure symptoms I don’t think… what are the symptoms?

Well…..When I had a lifter fail on my 2007 non-AFM 6.2L the symptoms where a loud screeching/tap sound. Nothing else. No misfires, no codes, nothing.

When I had a AFM lifter failure on my 2013 AFM 6.2L, the symptoms were a loud tapping sound. No misfires, no codes.

The fact that it is dependent on AFM actuation, the only mechanical aspect of that is literally the lifter expanding and collapsing. If it doesn’t fully go into AFM position, you won’t get a misfire because the motor isn’t trying to fire that cylinder.

 

[wjburken]

I hear you man, but it’s tough bc I have this on a loan and don’t wanna throw money at it if I don’t know 100% that it’s the lifters

I get the fact that you have a loan on the thing. That being said, I’d rather deal with replacing lifters vs having a catastrophic failure and having to deal with replacing a motor because you grenaded a lifter, chewed up a cam and sent shrapnel through the motor. I’ve been there and had to put a $6500 crate motor in because a lifter did just that. You can do what you want, but putting an AFM disabler on now is just kicking the can down the road and putting you at risk of having a bigger financial issue and a vehicle that is completely out of commission at a very inconvenient time.

 

[Dustin Jackson]

@wjburken I hear that man but these days money is tight so I think the best we can do is help them with the immediate problem and educate them on the rest of the situation so that WHEN the lifters do they fail they have a game plan already. I’m in boat of “if the motor is still running just drive it until the lifters fail” and then you can do the AFM delete.

I went really hard in a thread the other day on here about a guy who smacked his lifter until it opened back up and it was totally not worth my time giving my 2 cents in that situation.

 

[Dustin Jackson]

With that being said @iboughtatahoe23 please educate yourself on what you will do when the day comes that your motor is rattling and knocking.

Same happened to me, I spent a week calling shops and getting used motor quotes before I hit the bullet and ordered the AFM delete kit and installed it myself.

My advise is when you do have a lifter failure, open the motor up yourself and find the damage with your own eyes so that you can repair it properly. I’d say 75% of these motors are thrown away for simple lifter failures because the problem isn’t correctly diagnosed and they would rather just throw a replacement motor in it.

 

[wjburken]

@iboughtatahoe23, If you don’t have the money to fix it now, get a plan in place to get the money, and maybe the tools/knowledge to do the work yourself and save some money so you can fix it when it’s no longer an option. As @Dustin Jackson said, it’s not an if it will fail situation, it’s a when it will fail situation. You may have a week or you may have month or two, maybe more, but you will need to do something soon most likely.

 

[j91z28d1]

sounds like dad is old enough to remember when chevy engines were reliable.. just change the oil and they went 300k with a few tune ups.

sadly those days died with this afm stuff, and seems to still be an issue with new ones today. it's a shame.

I wonder how long it will last for him. I don't see afm delete kits as something he's going to do.

 

[lightflyer1]

Tried one of these instead of the range disabler. Works and doing the job for now. Going to send the ECU in soon to just turn it off and get rid of the Dongle.

https://www.amazon.com/dp/B0BQYNQ2SV?psc=1&ref=ppx_yo2ov_dt_b_product_details

 

[iboughtatahoe23]

sounds like dad is old enough to remember when chevy engines were reliable.. just change the oil and they went 300k with a few tune ups.

sadly those days died with this afm stuff, and seems to still be an issue with new ones today. it's a shame.

I wonder how long it will last for him. I don't see afm delete kits as something he's going to do.

No but it is something a shop can do for me.

 

[iboughtatahoe23]

Tried one of these instead of the range disabler. Works and doing the job for now. Going to send the ECU in soon to just turn it off and get rid of the Dongle.

https://www.amazon.com/dp/B0BQYNQ2SV?psc=1&ref=ppx_yo2ov_dt_b_product_details

Thank you will try this

 

[iboughtatahoe23]

With that being said @iboughtatahoe23 please educate yourself on what you will do when the day comes that your motor is rattling and knocking.

Same happened to me, I spent a week calling shops and getting used motor quotes before I hit the bullet and ordered the AFM delete kit and installed it myself.

My advise is when you do have a lifter failure, open the motor up yourself and find the damage with your own eyes so that you can repair it properly. I’d say 75% of these motors are thrown away for simple lifter failures because the problem isn’t correctly diagnosed and they would rather just throw a replacement motor in it.

I get the fact that you have a loan on the thing. That being said, I’d rather deal with replacing lifters vs having a catastrophic failure and having to deal with replacing a motor because you grenaded a lifter, chewed up a cam and sent shrapnel through the motor. I’ve been there and had to put a $6500 crate motor in because a lifter did just that. You can do what you want, but putting an AFM disabler on now is just kicking the can down the road and putting you at risk of having a bigger financial issue and a vehicle that is completely out of commission at a very inconvenient time.

So the disabler wont help at all? I only have the noise in v4 mode and it stopped when it kicked into v8.

And yea what’s $2500 loan for repairs on top of my vehicle loan. Bank said they could approve me. It’s just a game of is that really the issue. Because, like I said, I only rode with the mechanic, and he said based off the sound, and that noise only happening in V4 mode (he finally heard the noise this time, I had went a few times before and they said they can’t hear the noise) that it’s most likely lifters. That’s not on paper or anything yet so

 

[iboughtatahoe23]

I’m a bit confused because a lot of people recommend the plug in Disablers and they work fine they say.


But if my problem is worse , like an already failed lifter I could see why it wouldn’t work really. It might stop my noise and stop further damage?

Or I can do that Texas speed AFM delete kit or WhatVer with the new lifters