L99 Engine noise? Is this normal sound? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

ReVeNanTSS · 07-04-2020, 11:53 AM

Hi all, guys!

New here. It is my first thread.

Please listen and describe your opinion:

https://youtu.be/sUDU3tzReQY

Modernmusclecar · 07-04-2020, 12:15 PM

No that chirping sound is not normal. It sounds like a belt.

lemontwist · 07-04-2020, 12:23 PM

do you mean that knocking sound that may be a little piston slap

other than that it sounds kinda normal to me. don't jump to the lifter thing. youtube audio sucks for armchair diagnostics.

ReVeNanTSS · 07-04-2020, 12:39 PM

Quote:

Originally Posted by Modernmusclecar

No that chirping sound is not normal. It sounds like a belt.

Like belt? It is metallic sound i think

ReVeNanTSS · 07-04-2020, 12:39 PM

Quote:

Originally Posted by lemontwist

do you mean that knocking sound that may be a little piston slap

other than that it sounds kinda normal to me. don't jump to the lifter thing. youtube audio sucks for armchair diagnostics.

Omg, piaton slap it is worth thing it can be...

ReVeNanTSS · 07-04-2020, 02:44 PM

Can I inspect if open valve covers? Too eliminate lifter issue

InFiD3ViL · 07-04-2020, 04:15 PM

Yes, you can pop the valve covers and check the rockers as well. It really doesn't sound bad to me though...It sounds like an LS to me. But I understand it isn't easy to hear everything over a video.

Does it get worse when revved?

Vegas Bound · 07-04-2020, 05:13 PM

Lifter or bearing.

ReVeNanTSS · 07-04-2020, 05:52 PM

Quote:

Originally Posted by InFiD3ViL

Yes, you can pop the valve covers and check the rockers as well. It really doesn't sound bad to me though...It sounds like an LS to me. But I understand it isn't easy to hear everything over a video.

Does it get worse when revved?

When I rev I cant hear noise it becomes too noise there)

ReVeNanTSS · 07-04-2020, 05:58 PM

Quote:

Originally Posted by Vegas Bound

Lifter or bearing.

AFM lifter? Which bearing?

Vegas Bound · 07-04-2020, 06:49 PM

Quote:

Originally Posted by ReVeNanTSS

AFM lifter? Which bearing?

There is a known issue with the DOD/AFM lifters. Could be either rod or main bearing. From what I hear on the less than perfect audio, it sounds like a rod bearing. A slappy/banging sound. But again, hard to tell from the audio. Do you have access to an automotive stethoscope? You can narrow down the location without removing anything.

ReVeNanTSS · 07-04-2020, 07:27 PM

Quote:

Originally Posted by Vegas Bound

There is a known issue with the DOD/AFM lifters. Could be either rod or main bearing. From what I hear on the less than perfect audio, it sounds like a rod bearing. A slappy/banging sound. But again, hard to tell from the audio. Do you have access to an automotive stethoscope? You can narrow down the location without removing anything.

I will use stethoscope will see what it shows. This noise is more when oil is not warm

Modernmusclecar · 07-05-2020, 11:25 AM

Quote:

Originally Posted by ReVeNanTSS

Like belt? It is metallic sound i think

I've had an l99 for 8 years. Lifter tick is normal. Knocking or metallic noise of any kind is not. The squeek I hear doesn't sound metallic. It's hard to judge through the Internet. The noise I'm hearing may be feeback but the low knocking noise is not normal. And when an AFM lifter goes bad..there is no guessing. You know.

ReVeNanTSS · 07-05-2020, 07:12 PM

Quote:

Originally Posted by Modernmusclecar

I've had an l99 for 8 years. Lifter tick is normal. Knocking or metallic noise of any kind is not. The squeek I hear doesn't sound metallic. It's hard to judge through the Internet. The noise I'm hearing may be feeback but the low knocking noise is not normal. And when an AFM lifter goes bad..there is no guessing. You know.

I found out it is knocking on cold oil. when oil reaches 95-100 C it becomes normal. It looks it is lifters. I need change all 16 lifters. I cant find lifters on ebay.

Note: A V8 AFM engine requires 8 AFM lifters and 8 non-AFM lifters for a total of 16 lifters.

Part Number Description Qty
12576400 Non AFM Hydraulic Valve Lifter 8
12632143 AFM Hydraulic Valve Lifter 8

07-04-2020, 11:53 AM	#1
ReVeNanTSS Drives: 2012 Camaro SS 45th Anniversary EU Join Date: Jun 2020 Location: Azerbaijan Posts: 62	L99 Engine noise? Is this normal sound? Hi all, guys! New here. It is my first thread. Please listen and describe your opinion: https://youtu.be/sUDU3tzReQY

07-04-2020, 04:15 PM	#7
InFiD3ViL Drives: 2010 CGM 2SS/RS LS3 Swapped A6 Join Date: Sep 2016 Location: Spring Hill, FL Posts: 4,735	Yes, you can pop the valve covers and check the rockers as well. It really doesn't sound bad to me though...It sounds like an LS to me. But I understand it isn't easy to hear everything over a video. Does it get worse when revved? __________________ 2010 CGM Camaro 2SS LS3 Swapped A6 - GPI LS3 SS1 .647/.638, (224/237, 112 +4, 7º overlap) on CamMotion 8620 core, BTR Platinum .660" Dual Spring kit w/titanium retainers, CHE bronze trunnion upgrade, stock heads milled @ .015, Melling HV 10296 oil pump, TSP 1-7/8" long tube headers (W/Catless Off-road Pipes), Corsa Xtreme 3" Catback, GPI Ported/Rod Mod Intake, Stage 2 Ported Throttle Body, Vararam OTR CAI, Mike Norris Gen 2 catch can + GM 1LE clean side separator, 160º thermostat - Megan Racing adjustable coilovers (lowered 1.75"), MRR M017 10/11" wheels-Tuned by Ryan @ GPI

07-04-2020, 12:15 PM	#2
Modernmusclecar Drives: 2011 Camaro SS Join Date: Jul 2019 Location: Parts unknown Posts: 848	No that chirping sound is not normal. It sounds like a belt.

07-04-2020, 12:23 PM	#3
lemontwist Drives: 12 2SS/RS L99,11 2SS/RS LS3totaled Join Date: Jun 2019 Location: mooresville nc Posts: 1,048	do you mean that knocking sound that may be a little piston slap other than that it sounds kinda normal to me. don't jump to the lifter thing. youtube audio sucks for armchair diagnostics.

07-04-2020, 02:44 PM	#6
ReVeNanTSS Drives: 2012 Camaro SS 45th Anniversary EU Join Date: Jun 2020 Location: Azerbaijan Posts: 62	Can I inspect if open valve covers? Too eliminate lifter issue

07-04-2020, 05:13 PM	#8
Vegas Bound Account Suspended Drives: 2013 Sparkly Red One Join Date: Dec 2018 Location: Hospitality State Posts: 2,558	Lifter or bearing.