Vf redline ii ls3 piston slap again!

[EYY]

But what could they possibly do to reduce or stop the noise? They could go to all the trouble of ripping the engine to pieces, put it back together and find you have the same noise. They woudl need to do something pretty well known and specific to make it right. i woudl love to know what that is.

Fit new Pistons with tighter piston to bore clearances. They're probably on the loose side from the factory as loose Pistons have less chance of expanding too quickly and seizing during the running in period. They also take into account that many owners will flog the car when it's cold. The piston expands more quickly than the block, so extra clearance avoids cold seizure.

Does the noise go away once it's warm?

 

[Banjo79]

I myself am suffering whats being described . I've posted in the piston slap/cold start thread about it.
I just pretend I'm piloting a Blackbird SR-71 plane which leaks fuel when cold and has loose tolerances in strategic areas to allow for expansion when coming up to temp (mach 3).
Just makes those first 15mins of driving/flying that bit more tolerable.

 

[Ron Burgundy]

Mine sounds similar but only under load for the first 5 minutes when completely cold...in the morning generally
I can live with it....

 

[Ron Burgundy]

What was the outcome with yours redlineross ?

 

[monstar]

Sounds exactly like paranoia to me.
Piston slap from new cast pistons on engine with less than 50k km?!
Cold start noise can be reduced, but bottom line is that although we can lessen the impact of unwanted noise it is symptomatic of a cold engine, and it really should not be driven until warm.

 

[Immortality]

Sounds exactly like paranoia to me.
Piston slap from new cast pistons on engine with less than 50k km?!
Cold start noise can be reduced, but bottom line is that although we can lessen the impact of unwanted noise it is symptomatic of a cold engine, and it really should not be driven until warm.

Really, I think we are way past the days of having to wait for the engine to heat up before driving it. Even your owners manual in your shiny new car from Holden will say exactly that. Just don't thrash it from cold

Modern engines run extremely tight tolerances because modern pistons are made from much better materials that don't expand to much which should in theory reduce the chances of these exact issues.

I recon part of the issue is how these brand new engines are been run in.

The first LS motors had a lot of issues with piston slap and burning oil. Part of the problem (as I understand it) was the use of low tension rings to reduce friction and therefore improve economy, the other was how the engine was run in. I happen to know an ex Holden mechanic who did a lot of the repairs on these engines under warranty at the local Holden dealership. Once the new pistons/rings were fitted the cars were taken out and given a decent run to bed the rings in properly. The only way to bed rings in correctly is with a decent amount of engine load. Driving a new engine around like a grandpa is probably the worst thing you can do!

 

[monstar]

@immortality I agree, but the issue is not whether you have to wait for them to warm up but yeah, you should wait long enough for cold start to come out of open loop at least. Certainly if you don't like the sound of knocks and clunks.
Yes LS1 was different, the GenIV has hypereutectic cast slugs and revised ring spec. That sound OP recorded whilst moving is not the LS1 piston slap, more like induction wave hitting second harmonic, like it should.
The stationary noise top left bank at rear is evident on cylinder 8 all 821 cast heads. It is just a noise, not symptomatic of anything down below like piston rings slapping around the bore?!
Also agree about correct run-in for bedding rings, but that doesn't mean hair-on-fire rev the crap out of it / drive like racecar as some idiots now think. Each to their own, I'm near 50 (grandpa) and 300k km in with this motor, reckon there's zero need to run the cold engine like it's hot, or panic and bring it near the brink of oblivion at run in.
I find this relaxing MLV blanket helped quash paranoia in my aging years:

 

[panhead]

lol c63 makes all kinds of noise and burn oil as well, no difference there haha.

They only burn oil during the engine's settling in period then they calm down and use very little.

You are told this at delivery and you can drop into a Mercedes dealership at anytime and they will have a service employee come over straight away and top it up free of charge plus if you like to wait a little longer they'll serve you coffee and something to eat also at no charge.

The AMG's are very mechanical sounding as they are a very different animal to the pushrod setup GM uses.


.

 

[monstar]

They only burn oil during the engine's settling in period then they calm down and use very little.

You are told this at delivery and you can drop into a Mercedes dealership at anytime and they will have a service employee come over straight away and top it up free of charge plus if you like to wait a little longer they'll serve you coffee and something to eat also at no charge.

The AMG's are very mechanical sounding as they are a very different animal to the pushrod setup GM uses.


.

No surprise MB and AMG blow smoke and drink oil out of the box, they really are nothing special mechanically and quite over rated. In fact the company stinks.
The corporate arrogance starts with billions in useless garbage advertising of their Chinese shitboxes through "best or nothing" sales pitch then the after sales service is borderline criminal.

 

[Anthony121]

Don't rev a cold Aluminum engine over 2,000 revs until warm.