Need Help With Piston Slap Probs

[minux]

Remember these are ALLOY blocks, every noise is intensified 100 fold, thats what annoys me most about people with knocks in these engines, they dont realise they echo like a bitch.

If its not using oil and the knock is dissapearing after a few minutes, then there really isnt any problem, mine has done it on start up for the last 3 years, ive had cams done, drive it hard(acclerate quite often) never uses oil. My gf's had a brand new motor stuck in under warranty just 6 months ago(extended 5 year warranty) it is knocking too but within limits

 

[synoptica]

The simple fact is, the engine has developed a knock since he got it. Doesn't matter if it's 'within acceptable tolerances'... if my engine had developed a knocking noise since I got it, and it was under warranty, a noise like that wouldn't be acceptable to my standards, and thus he is entitled to a repair.

Bottom line: the engine is not functioning correctly. A correctly functioning engine does not make knocking sounds for 5 odd minutes after startup.

Why are people defending the car here?

 

[fitzy2005]

dont use thicker oil then what your car manual recommends, if its too think itll put more stain which will cause more fuel usage

 

[fitzy2005]

becuase cars arent ment to last for ever, so a slight noise doesnt worry any one but any one with vx's it must just suck, as they tend to be just outa warranty now

 

[Wombat]

I don't want to take the piss here, but sometimes here, as well as in magazines and other articles, people feel they should get on bended knee and worship the almighty Gen III V8, when by all reports it is a pox bucket just waiting for a suitable day to go bang at some time in the future.

I have however seen one or two (and only one or two) realistic articles over the years which have said that the Gen III was a bad mistake by Holden, and they should have stuck to something with a cast iron block..."planned obsolescence" went out in the USA back in the seventies...why should Australian drivers simply accept an engine which not only has several major faults like piston slap and massive oil consumption widely reported from new, but which probably won't have the same long and trouble-free life of older "low tech" iron block V8's?

As for warrantee...if I bought anything and the motor became noisy and started using the amounts of oil quoted above (which are simply ludicrous for a modern 21'st century engine, you have to admit! :unsure: ), I would be raising hold hell in the service department, warrantee company, and small claims court until it was either fully rebuilt or replaced completely.

 

[MOTIV8]

I wouldn't be happy at all if a so called modern engine like a Gen III V8 was making noises like that. There really isn't any excuse for it and having read about this problem in many different places over time I wouldn't part with my money to buy one.

 

[minux]

I don't want to take the piss here, but sometimes here, as well as in magazines and other articles, people feel they should get on bended knee and worship the almighty Gen III V8, when by all reports it is a pox bucket just waiting for a suitable day to go bang at some time in the future.

I have however seen one or two (and only one or two) realistic articles over the years which have said that the Gen III was a bad mistake by Holden, and they should have stuck to something with a cast iron block..."planned obsolescence" went out in the USA back in the seventies...why should Australian drivers simply accept an engine which not only has several major faults like piston slap and massive oil consumption widely reported from new, but which probably won't have the same long and trouble-free life of older "low tech" iron block V8's?

As for warrantee...if I bought anything and the motor became noisy and started using the amounts of oil quoted above (which are simply ludicrous for a modern 21'st century engine, you have to admit! :unsure: ), I would be raising hold hell in the service department, warrantee company, and small claims court until it was either fully rebuilt or replaced completely.

Every engien ive heard of that has used oil has done so within warranty, usually happens after 20000k(as it did with us). With the excess oil consumption holden replace the engine under warranty, one of our SS's had the problem, engine was replaced 110k later engine is running like a charm, i wouldnt give away my LS1 for a 304 for quids. The LS1 is a far better motor in my eyes

 

[VTSSDUDE]

Yep, I like my Gen III. I don't mind a slight knocking sound on first thing cold startup. Because when it gets to bruising time you tend to forget the bad things about the engine :yeah:
By the way about modern engines shouldn't be consuming oil and making sounds. How is the Gen III different to any other older engine. Still has bearings, conrods, and pistons.

 

[Don Sutton]

If you care to enter 'GM Piston Slap' into Google you will come back with pages of info about this in particular class actions through the courts in the USA. The reason these pistons slap is that the skirt is short (to save weight and friction) and they can rock in the bore where the rings will pulse in and out against the bore which gives high oil consumption or simply just give a single rock on the power stroke producing a sharp metallic knock. It is unlikely to cause a problem in terms of durability but is annoying to the owner and can reduce resale value. There is another issue where the knocking can be picked up by the knock sensor and interpreted as detonation. The spark will then retard and if knocking continues can result in a loss of performance and in some cases can bring on the the yellow service light. This was happening on my other car which is a V6 Vectra 2.5. In the case of the Vectra it is having a new short block fitted as the piston had collapsed 0.008", well outside limits. The replacement shortblock is a 2.6 which has a gudgeon pin offset greater than the 0 of the 2.5, designed to reduce piston slap. It seems to me that the Holden engines need this piston mod also.

 

[235rwkw]

If you care to enter 'GM Piston Slap' into Google you will come back with pages of info about this in particular class actions through the courts in the USA. The reason these pistons slap is that the skirt is short (to save weight and friction) and they can rock in the bore where the rings will pulse in and out against the bore which gives high oil consumption or simply just give a single rock on the power stroke producing a sharp metallic knock. It is unlikely to cause a problem in terms of durability but is annoying to the owner and can reduce resale value. There is another issue where the knocking can be picked up by the knock sensor and interpreted as detonation. The spark will then retard and if knocking continues can result in a loss of performance and in some cases can bring on the the yellow service light. This was happening on my other car which is a V6 Vectra 2.5. In the case of the Vectra it is having a new short block fitted as the piston had collapsed 0.008", well outside limits. The replacement shortblock is a 2.6 which has a gudgeon pin offset greater than the 0 of the 2.5, designed to reduce piston slap. It seems to me that the Holden engines need this piston mod also.

they did relocate the pins on later ls1's vy2 on i think.

a little noise cold is ok. no oil usage don't worry about it. if using oil too go see holden to see if they will cough up a free new set of pistons.