engine noise

[Robert Joye]

I bought a 2009 gmc Sierra with a 5.3 vortex engine with 51000 original miles on it. It has a tapping noise at start up.quiets down after engine warms.Is this normal or do I need to have it looked at?

[Sharpz]

It seems it is pretty common

[Dustoff87]

It's probably one of the hydraulic lifters on one of the AFM cylinders ticking against the cam assembly. Very common problem. Could also be a small leak on your exhaust manifold which seals up after the engine warms up.

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[Robert Joye]

4 hours ago, Sharpz said:

It seems it is pretty common

Thanks I've heard that alot.. just worried about it because it's New to me

[CamGTP]

Piston slap is always very common to the LS engine. Once the engine warms up, the pistons expand and the noise slowly goes away.

[Robert Joye]

14 hours ago, CamGTP said:

Piston slap is always very common to the LS engine. Once the engine warms up, the pistons expand and the noise slowly goes away.

 

[Robert Joye]

So should I have it looked at?

[Robert Joye]

21 hours ago, Sharpz said:

It seems it is pretty common

So should I worry about it ?

[Sharpz]

4 hours ago, Robert Joye said:

So should I worry about it ?

no. I know many people who have this issue and are pushing near 300k.  If you keep up with your truck, and keep an eye on things like Oil pressure, temp etc you should also get many miles out of your motor.

[Robert Joye]

Thanks that makes me feel a little bit better

[swathdiver]

On 3/14/2021 at 11:23 AM, Robert Joye said:

I bought a 2009 gmc Sierra with a 5.3 vortex engine with 51000 original miles on it. It has a tapping noise at start up.quiets down after engine warms.Is this normal or do I need to have it looked at?

Get a bi-directional scan tool on it and check for misfires and can also function test the  AFM system.  Do the easy stuff first, check the plugs, compression test, check for exhaust leaks, get a mechanic's stethoscope and listen around to pinpoint the noise, etc.  You can even use a screwdriver or extension stuck to your ear and whatever you want to listen to.

[Robert Joye]

Thanks. I listened to it with a rod to my ear it sounds like a valve or lifter tap to me

[Dustoff87]

Can you isolate which cylinder? If it's an AFM cylinder I'd consider getting a programmer or a range kit to deactivate it before the lifter collapses.

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