Ron Burgundy
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- Jun 3, 2004
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As some of you might know i was investigating cold start noise on my LS3. Rattles for only a few minutes until it reaches the operating temperature. Two holden dealerships said it was not a concern and a lot of people here had different theories.
Today I ended up consulting Sonny from Autowerks....and for those who are not familiar, he is one of the best and most reputable engine builders and tuners in NSW.
He saw the videos I took and told me he knew exactly what the issue was.
EXCESS PISTON TO BORE CLEARANCE - aka infamous piston slap.
He knew this as they came accross two LS3 engines with identical issue. One of them was brand new crate engine LS3 that they purchased. Holden did not acknowledge the issue so they ended up pulling apart brand new LS3.
The found that piston to bore clearance which is meant to be .002 was .006 and after adressing the clearance issue the engine was quiet as a mouse.
He also strongly advised not to let Holden pull it apart as they are not really engine builders and would probably make other things worse.
He took his time to look at this and talk to me free of charge. He at no point suggested for them to fix it and for those who know Sonny...he is one of the most honest guys and he provided advice without any self interest.
He said that it will generally not affect the performace and longevity of the engine but as the engine wears and tolerances increase the noise will get worse.
I am now stuck with this as I dont want Holden to pull it apart. I might start the process of insisting to have the engine replaced but I suspect I will not get very far.
The issue is not common on LS3 but some engines are slighly out of spec. from the factory...
For those who did not hear my engine on cold start I will paste some links in the post below.
Today I ended up consulting Sonny from Autowerks....and for those who are not familiar, he is one of the best and most reputable engine builders and tuners in NSW.
He saw the videos I took and told me he knew exactly what the issue was.
EXCESS PISTON TO BORE CLEARANCE - aka infamous piston slap.
He knew this as they came accross two LS3 engines with identical issue. One of them was brand new crate engine LS3 that they purchased. Holden did not acknowledge the issue so they ended up pulling apart brand new LS3.
The found that piston to bore clearance which is meant to be .002 was .006 and after adressing the clearance issue the engine was quiet as a mouse.
He also strongly advised not to let Holden pull it apart as they are not really engine builders and would probably make other things worse.
He took his time to look at this and talk to me free of charge. He at no point suggested for them to fix it and for those who know Sonny...he is one of the most honest guys and he provided advice without any self interest.
He said that it will generally not affect the performace and longevity of the engine but as the engine wears and tolerances increase the noise will get worse.
I am now stuck with this as I dont want Holden to pull it apart. I might start the process of insisting to have the engine replaced but I suspect I will not get very far.
The issue is not common on LS3 but some engines are slighly out of spec. from the factory...
For those who did not hear my engine on cold start I will paste some links in the post below.
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