2013 Tahoe LS top end noise

[Dustin Jackson]

@Just00Jake Unfortunately rockers can still move normally even if you are having a lifter issue and depending where you are at in the stroke it is normal for some rockers to have a little play when they are not under tension.

When I tore my motor down I was not able to find any indication that ANYTHING was wrong until I got the lifters and cam out. Until that point everything was tight and moved properly.

I think what happens is the lifter gets stuck and then is damaged. It becomes unstuck but now you are left with a flat spot on the lifter which causes it to jump while it rides on the cam and that might be the quiet tapping you are hearing now.

Are you getting a misfire on a specific cylinder?

 

[Geotrash]

@Just00Jake Unfortunately rockers can still move normally even if you are having a lifter issue and depending where you are at in the stroke it is normal for some rockers to have a little play when they are not under tension.

When I tore my motor down I was not able to find any indication that ANYTHING was wrong until I got the lifters and cam out. Until that point everything was tight and moved properly.

I think what happens is the lifter gets stuck and then is damaged. It becomes unstuck but now you are left with a flat spot on the lifter which causes it to jump while it rides on the cam and that might be the quiet tapping you are hearing now.

Are you getting a misfire on a specific cylinder?

Agreed. Was hoping that if he had a lifter still collapsed, running it with the valve cover off would confirm which one. I'm afraid this one's gonna need to come apart.

 

[Just00Jake]

@Just00Jake Unfortunately rockers can still move normally even if you are having a lifter issue and depending where you are at in the stroke it is normal for some rockers to have a little play when they are not under tension.

When I tore my motor down I was not able to find any indication that ANYTHING was wrong until I got the lifters and cam out. Until that point everything was tight and moved properly.

I think what happens is the lifter gets stuck and then is damaged. It becomes unstuck but now you are left with a flat spot on the lifter which causes it to jump while it rides on the cam and that might be the quiet tapping you are hearing now.

Are you getting a misfire on a specific cylinder?

Hey thank you for responding, yes I was getting a misfire on #2 (P302) before I did the top end cleaning and it went away, but I'm not sure if it has returned since this lifter noise started, I'm actually not trying to run it for a second longer than necessary. Upon plugging in my computer I'm getting a P219(A)&(B) and also getting a P521. So the P302 is gone and these are new. Now I'm really puzzled. This started about 100 miles after the top end cleaning

 

[Geotrash]

Hey thank you for responding, yes I was getting a misfire on #2 (P302) before I did the top end cleaning and it went away, but I'm not sure if it has returned since this lifter noise started, I'm actually not trying to run it for a second longer than necessary. Upon plugging in my computer I'm getting a P219(A)&(B) and also getting a P521. So the P302 is gone and these are new. Now I'm really puzzled. This started about 100 miles after the top end cleaning

P521 could be related. If you broke loose a bunch of gunk and debris with the cleaning, then it could've fouled the screen on the oil pressure sensor, which could then impact oil pressure and delivery to the VLOM and lifters for switching modes. Perfect candidate for an AFM delete.

 

[Just00Jake]

P521 could be related. If you broke loose a bunch of gunk and debris with the cleaning, then it could've fouled the screen on the oil pressure sensor, which could then impact oil pressure and delivery to the VLOM and lifters for switching modes. Perfect candidate for an AFM delete.

I understand what you are saying mostly, please forgive my confusion in just wrapping my head around the DOD as well as the whole AFM thing. I'm just wondering does the AFM effect the oil flow? And I'm also wondering since #2 is not one of the cylinders that is AFM controlled would this issue still be as I'm understanding possibly caused by the AFM system? I've watched and read about the AFM delete. It's gonna run about $150 total if I remember

 

[tom3]

Watching video really close and it looks like the front rocker arm has about half the lift it should?

 

[iamdub]

Watching video really close and it looks like the front rocker arm has about half the lift it should?

This is what I see.

 

[Dustin Jackson]

I understand what you are saying mostly, please forgive my confusion in just wrapping my head around the DOD as well as the whole AFM thing. I'm just wondering does the AFM effect the oil flow? And I'm also wondering since #2 is not one of the cylinders that is AFM controlled would this issue still be as I'm understanding possibly caused by the AFM system? I've watched and read about the AFM delete. It's gonna run about $150 total if I remember

@Just00Jake You are far past the point of a $150 AFM *disable*.

You need to tear your engine down and find the problem, there is certainly a mechanical issue.

Depending on the problem it could be easily fixed and you could rebuild it with nonAFM parts since it will need new parts anyways.

 

[89Suburban]

You can use a heavy leather glove to put pressure on each rocker to narrow down which one is clanking.

Maybe do a hail mary high rev to see it it blows something clear.

 

[Just00Jake]

@Just00Jake You are far past the point of a $150 AFM *disable*.

You need to tear your engine down and find the problem, there is certainly a mechanical issue.

Depending on the problem it could be easily fixed and you could rebuild it with nonAFM parts since it will need new parts anyways.

I have gotten my gasket set and replacement lifters, torque wrench etc. what I have yet to pick up is new head bolts (which one of you good gents suggested. I do have a question though, why do i keep hearing about the afm delete when swapping lifters? What do i need to do the delete? Is it necessary? And this surely sounds like a newb question, but when i asked for lifters, they are all the same, aren't the afm lifters different? Do I need new lifter trays?