Knocking sound when starting the engine??? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Yervais · 07-20-2011, 12:14 PM

I goes just for a second or so normally when starting cold, I can hear a knocking sound coming from the engine immediately after I start it...

You guys know anything about it?

Parker70 · 07-20-2011, 12:45 PM

A knock or a tapping sound. Do you have the L99 or the LS3? Some L99s (mine included) had lifter tapping on cold starts. There are several threads on this and a TSB about replacing the lifters.

The Stig · 07-20-2011, 12:50 PM

Are you putting at least 91 octane gas in? I know its a stupid question, but just want to check the obvious before diving into theories.

FLYBOY · 07-20-2011, 01:17 PM

If you have an auto, you have the L99 engine, and it's likely the lifters knocking. Mine does this also, like the guy above me said, there is a service bulletin for this issue and it's covered under warranty. Check out the issues forum on this site to find the thread about it.

Yervais · 07-20-2011, 01:36 PM

Sorry guys 2010 L99 and I use 93 but that shouldnt be an issue since knocking for bad gas is usually in high rpm or maybe its bad gas then?

Yervais · 07-20-2011, 01:39 PM

If its the liftter can it cause permanent damage or just the inconvinience of the noise?

Cam#7 · 07-20-2011, 01:41 PM

Could be a timing chain issue if the sound smooths out after the oil pressure gets up.

Parker70 · 07-20-2011, 02:00 PM

Quote:

Originally Posted by Yervais

If its the liftter can it cause permanent damage or just the inconvinience of the noise?

If it's the lifters, I've heard it's not supposed to be a big deal. That being said, I took mine in to the dealership in February and had the new AFM lifters installed. I haven't heard one tap since then.

10forty2 · 07-20-2011, 02:15 PM

Quote:

Originally Posted by Yervais

If its the liftter can it cause permanent damage or just the inconvinience of the noise?

Depends on if the lifter is not draining back down when you shut it off. Bad lifter can spell bent pushrod.....

The Stig · 07-20-2011, 02:27 PM

I'm going to have to agree with the masses here, you probably have a bad lifter. I would take it into the dealer just to be safe.

Yervais · 07-20-2011, 03:24 PM

Thanks guys!!! I appreciate it!!!

TRABlackCamaroSS · 07-20-2011, 03:44 PM

Putting my L99 in Monday @ the dealership ; replacing the lifters per TSB
Gonna miss her for a few days

Yervais · 07-26-2011, 07:32 PM

Let us know how it goes... Also is the sound more like a tapping noise or a ticking noise???

Yervais · 07-31-2011, 06:49 PM

any updates?

07-20-2011, 12:14 PM	#1
Yervais Drives: 2010 Camaro SS Join Date: Jun 2011 Location: Aguascalientes Posts: 56	Knocking sound when starting the engine??? I goes just for a second or so normally when starting cold, I can hear a knocking sound coming from the engine immediately after I start it... You guys know anything about it?

07-20-2011, 12:50 PM	#3
The Stig knows 2 facts about ducks Drives: ...and they're both wrong Join Date: Aug 2009 Location: The HMS Invincible Posts: 25,072 View My Garage	Are you putting at least 91 octane gas in? I know its a stupid question, but just want to check the obvious before diving into theories. __________________

07-20-2011, 02:27 PM	#10
The Stig knows 2 facts about ducks Drives: ...and they're both wrong Join Date: Aug 2009 Location: The HMS Invincible Posts: 25,072 View My Garage	I'm going to have to agree with the masses here, you probably have a bad lifter. I would take it into the dealer just to be safe. __________________

07-20-2011, 03:44 PM	#12
TRABlackCamaroSS Drives: '10 Blk Camaro SS/'08 Blk Silverado Join Date: Feb 2011 Location: OKLA Posts: 466 View My Garage	L99 lifters Putting my L99 in Monday @ the dealership ; replacing the lifters per TSB Gonna miss her for a few days

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07-20-2011, 12:45 PM	#2
Parker70 Drives: 2010 IOM 2SS/RS IO int, A6 Join Date: Feb 2010 Location: Roebuck, SC Posts: 102	A knock or a tapping sound. Do you have the L99 or the LS3? Some L99s (mine included) had lifter tapping on cold starts. There are several threads on this and a TSB about replacing the lifters.

07-20-2011, 01:17 PM	#4
FLYBOY Drives: Black 2010 2SS/RS A6 Join Date: Aug 2010 Location: Kansas Posts: 87	If you have an auto, you have the L99 engine, and it's likely the lifters knocking. Mine does this also, like the guy above me said, there is a service bulletin for this issue and it's covered under warranty. Check out the issues forum on this site to find the thread about it.

07-20-2011, 01:36 PM	#5
Yervais Drives: 2010 Camaro SS Join Date: Jun 2011 Location: Aguascalientes Posts: 56	Sorry guys 2010 L99 and I use 93 but that shouldnt be an issue since knocking for bad gas is usually in high rpm or maybe its bad gas then?

07-20-2011, 01:39 PM	#6
Yervais Drives: 2010 Camaro SS Join Date: Jun 2011 Location: Aguascalientes Posts: 56	If its the liftter can it cause permanent damage or just the inconvinience of the noise?

07-20-2011, 01:41 PM	#7
Cam#7 Drives: 2011 2LT IBM / SIM stripe 6M Join Date: Apr 2010 Location: STL Posts: 863	Could be a timing chain issue if the sound smooths out after the oil pressure gets up.

07-20-2011, 03:24 PM	#11
Yervais Drives: 2010 Camaro SS Join Date: Jun 2011 Location: Aguascalientes Posts: 56	Thanks guys!!! I appreciate it!!!

07-26-2011, 07:32 PM	#13
Yervais Drives: 2010 Camaro SS Join Date: Jun 2011 Location: Aguascalientes Posts: 56	Let us know how it goes... Also is the sound more like a tapping noise or a ticking noise???

07-31-2011, 06:49 PM	#14
Yervais Drives: 2010 Camaro SS Join Date: Jun 2011 Location: Aguascalientes Posts: 56	any updates?