Lifter Rattle

[geswek]

Obviously this is a controversial post; let me start off by saying I understand the "pay to play" and let's leave the stupid comments at the door.

 

I have a tune from Diablew in my Silverado.

 

What I have noticed from day 1 is that I'm fairly certain there is lifter rattle from the AFM system since I have it disabled. It's at random RPM's and occurs with load--for example going up a freeway onramp and I hit the throttle; somewhere around 3k rpms I will hear rattling like a paint can and it goes away. My question is: does anyone know if this will cause serious damage longterm? My question is whether I should put the stock tune back on and take it to GM. My issue with this is I am not sure how to "replicate" it with AFM on as I think that drowns out the noise I am hearing now. If they are defective and it wasn't a result of my tune--then I want to have it fixed but if it's just an annoyance because AFM is off and you can hear that; I'll just ignore it and move on.

 

I've been driving with it for 20k miles.

[diyer2]

IMO

I don't think you can make a determination weather this lifter will last.

If you're sure this is whats making the noise it has a problem.

 

[geswek]

I agree.

Just wondering if anyone else with AFM disables hears the same thing? I wasn’t sure if the AFM lifters are mosey by design or not.


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[Dnt]

Most likely this is your tune causing this and it is probably not lifter click it is most likely "spark knock"  See if this scenario sounds familiar - coasting along around 55 to 60 and rpm around 1500 1600 you give it a slight amount of gas pedal and the engine sounds like it is making a metallic clicking sound????  Your tunes spark advance curve is off under these certain conditions and yes if you continue to run with the noticeable "spark knock" it will shorten your engine life, possibly dramatically.  

[amxguy1970]

So you say you understand "pay to play" yet you want to have someone else pay and be deceitful? You do understand they can catch a tune even if removed right? There is always a finger print left behind as this has been a hot topic issue with manufacturers, they have stepped up their warranty process. Having to go in to an engine will require them to be thorough before getting approval and warranty something.

 

To answer your question, no you shouldn't put your stock tune in and be sneaky and try to get it covered. Take it in, let them know it is tuned and if it is not caused by the tune they will warranty it, if it is now you know and you can fix it your self and pay to continue to play.

 

Tyler

[geswek]

Most likely this is your tune causing this and it is probably not lifter click it is most likely "spark knock"  See if this scenario sounds familiar - coasting along around 55 to 60 and rpm around 1500 1600 you give it a slight amount of gas pedal and the engine sounds like it is making a metallic clicking sound????  Your tunes spark advance curve is off under these certain conditions and yes if you continue to run with the noticeable "spark knock" it will shorten your engine life, possibly dramatically.  

I’ll give that a shot—it actually sounds familiar.

I can load the stock and disabled AFM to see if it continues.

I’m wondering if Diablew turned something up too much.


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[Logan Lanfear]

Why not see if it still makes the noise without the tune running?  That may help narrow down the causes to see if it is a lifter or spark knock.

[geswek]

Why not see if it still makes the noise without the tune running?  That may help narrow down the causes to see if it is a lifter or spark knock.

It’s difficult to do when the truck transitions for v4 to v8.

I’m going to load stock tune with AFM off and see if it does it.

If it doesn’t I’m contacting Diablew.


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[Welder-32]

I just bought a 15 with 35,000 miles. Didn’t even have it a week and heard a lifter  tapping yesterday on my way to work. On the way my check engine lite came on and the tapping turned into a knocking. I called the Gm dealership where I bought it and they came and towed it and looked it over while I was at work. Got a call back end of the day and a lifter stuck bent a push rod and broke a rocker arm. Pretty sure it bent a valve  as well. The tech told me a bulletin just came out for this issue. There was another 15 there with the same problem. I never had a programmer or anything else. Completely stock. Don’t know if this will help you or not but I would definitely get it checked out! 

[geswek]

Interesting.


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[Tahoe02]

I thought I read you can use towing mode and it will put the truck in D5 and keep it out of v4. You could probably Google search or someone on here may know. Don't know if this would help with your diagnosis or not.

[geswek]

I tried it didn’t work.

I have modified stock tune in now. It’s completely stock with just AFM off. I’m out testing it now.


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[Tahoe02]

I just read a "throttle response" post and said to put it in M5 to keep it out of v4 unless your tune won't allow it.

[geswek]

Good news.

I can’t replicate it now no matter what I do.

I’m assuming what I heard was actually spark knock which sounded like someone shaking a paint can.


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[Bwoodkid]

On ‎2‎/‎10‎/‎2018 at 6:16 AM, geswek said:

Obviously this is a controversial post; let me start off by saying I understand the "pay to play" and let's leave the stupid comments at the door.

 

I have a tune from Diablew in my Silverado.

 

What I have noticed from day 1 is that I'm fairly certain there is lifter rattle from the AFM system since I have it disabled. It's at random RPM's and occurs with load--for example going up a freeway onramp and I hit the throttle; somewhere around 3k rpms I will hear rattling like a paint can and it goes away. My question is: does anyone know if this will cause serious damage longterm? My question is whether I should put the stock tune back on and take it to GM. My issue with this is I am not sure how to "replicate" it with AFM on as I think that drowns out the noise I am hearing now. If they are defective and it wasn't a result of my tune--then I want to have it fixed but if it's just an annoyance because AFM is off and you can hear that; I'll just ignore it and move on.

 

I've been driving with it for 20k miles.

my !5 did the same thing with the 91/92 tune, pretty sur its a bit of knocking. I let Diablew know about it. He adjusted my tune and it was fine.  make sure you use the higher of the octane and good gas. if you can.