LS3 Lifter noise or Piston Slap?

[RevNev]

Just been told it is most likely a delaminated piston

Sounds like a lifter noise to me from the video acoustics. Piston slap to be that loud would take it nipping in the bore with significant piston shrinkage at the skirt. Even a slappy race engine with forged pistons at 5 or 6 thou piston to bore clearance isn't that pronounced to really grab your attention to the extent of questioning "what's that noise?" Tie bar lifter noise on a mechanical roller camshaft drowns out the piston slap.

Lifter noise is common as the open valves subject to valve spring pressure bleeds a hydraulic lifter down and creates rocker to valve tip clearance until the oil pressure pumps the lifter back up to zero clearance during warm up. Another lifter clatter engine when cold I've heard several times are 6.4 litre Hemi engines in the Jeep Grand Cherokee SRT.

Here's a Ecotec V6 race engine with forged piston slap at 0.005" piston to bore clearance

 

[DavesSV6Tonner]

Sounds like a lifter noise to me from the video acoustics. Piston slap to be that loud would take it nipping in the bore with significant piston shrinkage at the skirt. Even a slappy race engine with forged pistons at 5 or 6 thou piston to bore clearance isn't that pronounced to really grab your attention to the extent of questioning "what's that noise?" Tie bar lifter noise on a mechanical roller camshaft drowns out the piston slap.

Lifter noise is common as the open valves subject to valve spring pressure bleeds a hydraulic lifter down and creates rocker to valve tip clearance until the oil pressure pumps the lifter back up to zero clearance during warm up. Another lifter clatter engine when cold I've heard several times are 6.4 litre Hemi engines in the Jeep Grand Cherokee SRT.

Agree, sounds like a valve train noise to me.

 

[Martbar]

A little update on my noise (which i thought was extremely similar to @IBLOWN noise) and FYI to anyone else that has a similar noise.

Just been told it is most likely a delaminated piston. The place said they'll do a cold and hot compression test tomorrow and call with more info.
If they confirm thats it they said engine out jobby 4-5 grand

There needs to be a crying emoji.

Mate out of all the p/slap audio l listened to yours mimics ours exactly. When l complained about ours the dealership offered us our money back, another car or a free updated mechanical warranty. The warranty was 2 year or 200,000 and the maximum amount per claim was upped to $5000. Every mechanical component was covered and you could have multiple claims per year. Ours hasn't even got the LS motor. The point is your motor will probably be OK for 200-250,000kms. Even with the slap the motor doesn't burn any oil. Good luck with yours and try not to worry about it to much.

 

[Kakodaemon]

Thanks to everyone who replied, I really appreciate it.

@Skylarking @immortality
I bought the car back in 2019 from a dealer but that dealer is about 2 hours away from me.
I will be definitely telling the place to document everything as I will look at my options with ACC and Holden after the repair.

@Martbar
Did Holden say what it was and why they offered you multiple remedies without a shitfight?
Thanks but I'm afraid I can't help but worry about it, i need my car and don't need this expense right now

@RevNev @DavesSV6Tonner
I took it first to a mechanic a friend knows which is just down the road, showed him a video on my phone, he said it was lifters but wouldn't do it at his shop. I ended up taking it to a performance shop (mainly because they provide free car for all customers.) The guy at the shop said he would give it a decent service (it was due for one) and see if that fixed/helped the noise. He also said he would check the valvetrain as he said he has seen some valve springs break and cause noise. He said he checked over everything including the lifters and everything was ok.
He spoke to his engine builder and explained everything and he said its probably a delaminating (or delaminated not sure which one he said) piston.
I got the impression they weren't 100% sure exactly what is causing the noise, but apparently a small amount of metal was found in the oil.
Still waiting for the call back after the cold and hot compression test. I assume if there is no variation in compression on any of the cylinders then they'll be back to square one.

 

[Skylarking]

@Skylarking @immortality
I bought the car back in 2019 from a dealer but that dealer is about 2 hours away from me.
I will be definitely telling the place to document everything as I will look at my options with ACC and Holden after the repair.

My suggestion is don’t wait until the repair is done. I’d first call CAV, now, and discuss it with them else you may shoot yourself in the foot and not be able to claim repair costs. After talking to CAV I’d call ACCC and get their take on the issue of Holden sitting on known defective engines..

Do it, do It now…

 

[Martbar]

Thanks to everyone who replied, I really appreciate it.

@Skylarking @immortality
I bought the car back in 2019 from a dealer but that dealer is about 2 hours away from me.
I will be definitely telling the place to document everything as I will look at my options with ACC and Holden after the repair.

@Martbar
Did Holden say what it was and why they offered you multiple remedies without a shitfight?
Thanks but I'm afraid I can't help but worry about it, i need my car and don't need this expense right now

@RevNev @DavesSV6Tonner
I took it first to a mechanic a friend knows which is just down the road, showed him a video on my phone, he said it was lifters but wouldn't do it at his shop. I ended up taking it to a performance shop (mainly because they provide free car for all customers.) The guy at the shop said he would give it a decent service (it was due for one) and see if that fixed/helped the noise. He also said he would check the valvetrain as he said he has seen some valve springs break and cause noise. He said he checked over everything including the lifters and everything was ok.
He spoke to his engine builder and explained everything and he said its probably a delaminating (or delaminated not sure which one he said) piston.
I got the impression they weren't 100% sure exactly what is causing the noise, but apparently a small amount of metal was found in the oil.
Still waiting for the call back after the cold and hot compression test. I assume if there is no variation in compression on any of the cylinders then they'll be back to square one.

Hey mate, our car is a 2010 Calais with 85,000kms, piston slap was diagnosed by local former Holden dealership. I committed the cardinal sin of not test driving the car before buying it. Chev V8s used to be bulletproof, reasonably
low mileage car in exceptionally good condition, all good. GM doesn't see piston slap as a durability concern, and suprise, surprise, they didn't think that the noise in our car was excessive. It was mearly the "rattle of a high performance motor." In the VE threads l read most of the posts back to 2010, and they were having trouble with these engines in new cars, and when they replaced some of these engines under warranty, some of the replacement engines were just as bad or worse. Mate there are a lot of these engines around the place
and the audio of your motor is exactly the same as mine. Warm it up before driving, 1300rpm is the least amount of noise during the warmup phase of our engine. I felt sick when the p/slap was diagnosed, but when the dealership was prepared to insure the motor up to 200,000kms, I'm thinking if anything does happen to the motor that it probably won't have anything to do with the slap. Cheers mate.

 

[Kakodaemon]

So the shop i took my car to said that there is a Teflon coating on the sidewall of the piston which has worn off causing the piston head to not move straight up and down but tilt and move side to side which causes the knocking noise. They tested all lifters, valve springs and oil pressure and everything was ok. Will talk to him on Tuesday regarding time and price to fix it.

 

[07GTS]

any piston sidewall coating should make no difference to its control in the bore, not that i know any LS OE manufacture ever put any coatings on the pistons from factory, even the aftermarket that use the sidewall coatings they are all essentially sacrificial over time and arnt used it the actual clearance measurements

 

[lmoengnr]

any piston sidewall coating should make no difference to its control in the bore, not that i know any LS OE manufacture ever put any coatings on the pistons from factory, even the aftermarket that use the sidewall coatings they are all essentially sacrificial over time and arnt used it the actual clearance measurements

Especially Mexican LS3's...

 

[RevNev]

any piston sidewall coating should make no difference to its control in the bore, not that i know any LS OE manufacture ever put any coatings on the pistons from factory, even the aftermarket that use the sidewall coatings they are all essentially sacrificial over time and arnt used it the actual clearance measurements

They're talking about Teflon skirt pads on some 2618 forged race pistons to enable OEM piston to bore clearances without nipping the skirts in the bore with heat expansion. The 2618 Teflon skirt pad is used to reduce cold piston slap and forged piston noise interfering with knock sensors. I can't really see this technology used on a stock LS3 cast piston. A general Teflon skirt coating (non pad design) is an anti-abrasion coating and isn't thick enough or intended to reduce piston to bore clearance or cause piston slap if worn off.

What's a late LS3 piston look like, anyone have a photo of them?