Piston slap LS3 - this is very interesting

[Milo 6.0]

My tuner said its been an ongoing issue since the first gen 3 was released,he also mentioned it doesnt affect the longevity or reliabilty,his words not mine but i think he would know the product very well,he worked at holden for a long time, my other mate worked at holden for a while too,he used to replace 1 piston assemebly on piston slapping/oil burning gen 3s,not complete rebuilds or new motors.
Its been a known issue for a long time,not sure if its actually worse now or just that its more widely heard of/spoken of with the interwebs?

 

[Skylarking]

I don't recall piston slap ever being an issue with iron lions....is that coz iron or coz Holden did a better job than GM ?

long piston skirts in iron lions from what I understand

 

[abuch47]

Blaming mexico when every US OEM has manufacturing there. ‍

 

[Anthony121]

I believe the bigger issue is when it keeps slapping when hot.

Yes that is true. I have heard a LS3 doing that while at operating temp. To have this the vehicle must of had multiple cold thrashings before warm up. I have been told so not rev these engines when cold. Allow at least 10-15 mins before oil temp reaches full temp.

This is mechanical and nothing to do with a tune. The piston slap is mechanical not pinging.

 

[Anthony121]

Yes it does, sort of.
Simply halve the current tolerance so that when two parts at either end of the tolerance extreme are assembled they won’t be as sloppy as having wider tolerances... but that’s expensive and may even not be possible (maybe due to needing some bore to piston clearance).



The other approach is to batch them into different tighter tolerance groupings (pistons and blocks) so wider pistons go into blocks with wider holes with a much closer to spec bore to piston clearance

As I understand the later is easier and cheaper than the former but still more expensive than poor QC and simply not giving a ****

Do you think they have piston slap when fist started? I know my Redline didn't. Occurred much later while driving it.

WHY DO THESE POSTS change after posting to forum?

 

[07GTS]

GM have tried to help the slap sound during startup but it dosnt fix it, more spark can be more torque so more load on the unstable piston helping it out, i noticed no difference with this table populated or zeroed out but mine wasnt bad to begin with

 

[Milo 6.0]

Wow thats fkn sad,holden changing the tune to try and quieten down its mechanical shortcomings.... dont worry about fixing the issue just try and mask it, load of bs.

 

[Paulie81]

GM have tried to help the slap sound during startup but it dosnt fix it, more spark can be more torque so more load on the unstable piston helping it out, i noticed no difference with this table populated or zeroed out but mine wasnt bad to begin with

Is this the stock tune or does Holden flash this for customers who complain?

 

[Anthony121]

One thing I do notice after each oil change the engine is very quiet again at start up. I changed oil on Saturday and my knock is nearly non existent while cold now. It only lasts a few weeks but new oil makes a difference. I'll do that when it comes time to sell

 

[Immortality]

What oil do you run?