LS3 Oil pump failure?

[vombil]

So one of Perth's longest running performance type workshops has put his left nut on my noisy engine being a fractured oil pump gear - which is interesting given the dealership has conceded it's piston slap. It hasn't been pulled down and Holden is in front of the mag at the minute. I suppose all that I can expect now is that there is an order made for them to strip inspect and remedy the issue. No engine warning lights for pressure issues etc.

Does anyone have any evidence - factual or anecdotally of these pumps failing and what the symptoms are? The local engine builder told me he's done a handful of VF LS3's for slap and then the race mechanic tells me he's replaced at least 4 pumps on low kms LS3's!

Interestingly, the builder said that the pistons have a short skirt, and as such a propensity to move sideways in the bore, wearing the teflon coating off the skirts and causing the slappy knocky noise.

Talk about throwing a curve ball - cheers guys

 

[lmoengnr]

I thought oil pump gear failure was a Barra thing, sticky relief valves on early LS's?

 

[vombil]

I thought oil pump gear failure was a Barra thing, sticky relief valves on early LS's?

def the first ive heard of it

 

[Skylarking]

So given that piston slap is a thing with these LS3’s, I’d probably be more inclined to get a new engine which would resolve the broken oil pump

 

[Anthony121]

Does the noise go away when engine is at operating temperature?

 

[shane_3800]

The piston slap is due to loose tolerances of the pistons, rings, pins and the bore finish.
If the engine is built right you don't get these issues.

As for the oil pump, don't know I've never dealt with a cracked gerotor before.

 

[vombil]

Does the noise go away when engine is at operating temperature?

yeh, this golden oldie reckons its the fracture closing as the engine gets warm and it then making pressure to shut the lifters up... what a clown. I actually don't know why I bothered with him. He's absolutely got the worst diagnostics ability in the entire state. He sent my 383 out of his shop with the weighted flex 180 degrees out of alignment when it was there with a complaint for massive engine vibration which had sheered the last bell in half with previous owners shitty workmanship (diesel mechanic)

 

[vombil]

The piston slap is due to loose tolerances of the pistons, rings, pins and the bore finish.
If the engine is built right you don't get these issues.

As for the oil pump, don't know I've never dealt with a cracked gerotor before.

engine builder was telling me the compression ring is so damn tight and the skirt is so short that the bottom of the piston moves sideways and flogs the teflon coating off which is the cause of the noise - in his opinion

 

[vombil]

Does the noise go away when engine is at operating temperature?

it goes away well before operating temp. it's gone after 2 mins on the coldest morning and sometime as quickly as 30 seconds but it does it every single cold start. never on restart - even if it's sat for 6 hours

 

[Anthony121]

it goes away well before operating temp. it's gone after 2 mins on the coldest morning and sometime as quickly as 30 seconds but it does it every single cold start. never on restart - even if it's sat for 6 hours

My Redline does the same thing. My mechanic said it's piston slap. It is much quieter with fresh oil for a few weeks.