Piston slap or hydraulic lifters?

[07GTS]

Thanks for clarifying. I misunderstood the original source material.

i got a set of the JE Ultra boost forged 2618 pistons going into my build so i guess ill have to get use to some slap on cold startup, but they will handle hell all day long

 

[Ron Burgundy]

My new motor is less 'slappy' than the original one, but some noise, some of the time when cold is still there...
First 10 000 km new motor was quiet as...but now with 12 000km in colder morning it gets a bit noisy

 

[shane_3800]

You cannot get factory replacement LS3 engines anymore. Stock has been cleaned out.

As for the noise, just drive it easy until the engine warms up. I have one noisy engine and one quiet one. So far at 50k it hasn't got worse. It's much quieter with an oil change so thats what I'll do when its for sale

Yea you can lol. Holden might be "Factory" but GM performance sells the exact same engine widely in the aftermarket.

 

[shane_3800]

I don't think it's the pistons I swear these GM V8 blocks relax and let tolerances shift a little after heat cycling.
Hypers are a semi forged piston as they hammer the alloy powder into place then heat and machine.

 

[Paulie81]

My new motor is less 'slappy' than the original one, but some noise, some of the time when cold is still there...
First 10 000 km new motor was quiet as...but now with 12 000km in colder morning it gets a bit noisy

Thats around the same time I started to notice it on mine.

 

[Paulie81]

i got a set of the JE Ultra boost forged 2618 pistons going into my build so i guess ill have to get use to some slap on cold startup, but they will handle hell all day long

Well the fact that forged is known to slap must mean its an acceptable phenomenon and subject to a range of factors such as materials, piston design, clearance, ambient temperature etc.

Some here have claimed that GM have deliberately cut on quality control and although I can admit that GM quality is nowhere near as good as some other brands, I find it hard to believe they would have cut QC on this specific matter. Surely they would weigh up cost vs risk and consider the experience they had with earlier LS1 engines. Why would they foolishly expose themselves to litigation and a forced recall to repair all LS3 and other variants that are displaying a fault. It would cost them their reputation not to mention the significant financial burden to rectify the issues with a rebuild. Also the impact on their service network would be huge.

 

[lmoengnr]

Well the fact that forged is known to slap must mean its an acceptable phenomenon and subject to a range of factors such as materials, piston design, clearance, ambient temperature etc.

Some here have claimed that GM have deliberately cut on quality control and although I can admit that GM quality is nowhere near as good as some other brands, I find it hard to believe they would have cut QC on this specific matter. Surely they would weigh up cost vs risk and consider the experience they had with earlier LS1 engines. Why would they foolishly expose themselves to litigation and a forced recall to repair all LS3 and other variants that are displaying a fault. It would cost them their reputation not to mention the significant financial burden to rectify the issues with a rebuild. Also the impact on their service network would be huge.

If QC was an issue for GM, they wouldn't be building engines in Mexico...
LS3 quality has been an issue before.
HSV imported a bad batch 2010/11, they had soft cams, and were losing lobes in less than 5000kms.
Holden's LS3's were the last to be mass manufactured for OEM fitment.
They probably used up all the miss matched bits and pieces to clear inventory...
After all, it was being shipped half way around the world, to a place, and country, that GM management was about to dump.

 

[shane_3800]

GM is run by a wamen nuff said.

 

[Paulie81]

GM is run by a wamen nuff said.

With the last name Barra!

 

[Mayuri Krab]

I feel like I discover a new noise from my Engine every time I drive it lol

There's the "it sounds like slap but not sure" noise everytime I drive it for the 1st few minutes on a cold engine

Then the "different noise to before" after warming up

And "what's that click sound" that seem to appear randomly after the end of a long drive and idling...