Need Help With Piston Slap Probs

[Hairy Eater]

i must be darn lucky... my VX V6 has done 157,000 klms.... on startup i'm just so impressed how quiet it is... it's ecotech... i heard that V6's get to 400,000 klms no probs...

 

[Evman]

The Gen3 is a terrific engine. Excellent power, excellent economy, excellent aftermarket upgrades! Yes, there are a fair few problems, but it was in mass production on a huge scale. When you look at the engines that had problems, they'd be a very small (and acceptable) percentage of the total number of engines produced. No mass produced items will be perfect across the range, it's just a fact of life. That's what warranty is for, and thats why the ones that were outside acceptable tollerances were rebuilt.

 

[2000V8]

I run a Gen III V8 - had the engine rebuilt under warranty for piston slap - took three years of me telling them the timing chains were making noise (I am a woman!) and Holden finally did a rebuild about 1 month after warranty expired. The noise does come back and a couple of months ago it seemed worse than ever - but I have just had all the "rubbers" and engine mount "bushes" and things replaced and the engine seems to be running better than ever noise wise. Beware though, I now have an engine leak coming from the valley gasket, which is work they did on the rebuild, and am trying to get that fixed "under warranty" now.

 

[Don Sutton]

I don't believe that if you pay market value for a new car that you should bend over and accept knocking, and high oil consumption when rivals can achieve low oil consumption and no knocks and support the customer. I would find it hard to believe that a manufacturer sets out to produce a defective engine as a policy so either the design was defective and they are covering the bottom line by resisting warranty claims or the parts are defective meaning a quality control problem and they are covering the bottom line by resisting warranty claims. Unfortunatly this is the case with a number of manufacturers and they would be better off fessing up and standing by their products which would in the long term improve their public image.

 

[VTsuper6]

My brother in law had a VT2 Gen3, I had a VX Gen3 and there are 6 Gen3's at my work VX - VY and not 1 of these engines have shown signs of Piston Slap or high oil consumtion. In fact I was the only one in this group that knew anything about it. I do know 1 owner that did have piston slap on a VY1 but Holden replaced the engine and all is fine now. I am sure I would be unhappy if I did have these symptoms but I didn't thankfully. It is obvious to me that this problem is not evident on every Gen3 engine made. If anything, I would say that the majority of Gen3 engines would be fine.
For those Gen3 critics that have never actually owned a Gen3, keeping unqualified remarks to yourselves would be much appreciated. The Gen3 I had (until it was stolen) was the best V8 I have ever owned. Not only do you get the power, but you get the economy as well. Best of all, it costs buggerall to get 300 kw out of it. It's a much better overall engine package than the thirsty old 5.0 litre it replaced. However I do admit, nothing sounds as good as the old Holden 5.0 litre though.

 

[Don Sutton]

My brother in law had a VT2 Gen3, I had a VX Gen3 and there are 6 Gen3's at my work VX - VY and not 1 of these engines have shown signs of Piston Slap or high oil consumtion. In fact I was the only one in this group that knew anything about it. I do know 1 owner that did have piston slap on a VY1 but Holden replaced the engine and all is fine now. I am sure I would be unhappy if I did have these symptoms but I didn't thankfully. It is obvious to me that this problem is not evident on every Gen3 engine made. If anything, I would say that the majority of Gen3 engines would be fine.
For those Gen3 critics that have never actually owned a Gen3, keeping unqualified remarks to yourselves would be much appreciated. The Gen3 I had (until it was stolen) was the best V8 I have ever owned. Not only do you get the power, but you get the economy as well. Best of all, it costs buggerall to get 300 kw out of it. It's a much better overall engine package than the thirsty old 5.0 litre it replaced. However I do admit, nothing sounds as good as the old Holden 5.0 litre though.

What this proves is:
Because a lot of engines are OK means that it is not a design problem and that it is a quality problem which may be GM or it may be the supplier as some engines definately have a problem.

 

[VTsuper6]

What this proves is:
Because a lot of engines are OK means that it is not a design problem and that it is a quality problem which may be GM or it may be the supplier as some engines definately have a problem.

I tend to agree. But would you call it Quality or a Tolerence issue? Obviously GMH developed a testing criterea to determine which engines are worthy of a warranty repair or not. I'd say the ones way out of tolerance are repaired and the marginal ones are knocked back. Personally, I think if Piston Slap is detected by the Holden Dealer and if the Customer is unhappy with it, then Holden should Authorise a warranty repair.

 

[Don Sutton]

I tend to agree. But would you call it Quality or a Tolerence issue? Obviously GMH developed a testing criterea to determine which engines are worthy of a warranty repair or not. I'd say the ones way out of tolerance are repaired and the marginal ones are knocked back. Personally, I think if Piston Slap is detected by the Holden Dealer and if the Customer is unhappy with it, then Holden should Authorise a warranty repair.

Do you mean owner tolerance and Holden quality?
Tolerance and quality go hand in hand. The issue hear is that Holden have devised a level by which they can minimise the extent of work and therefore cost to them. There has to be a reasonable level of oil consumption so that valve stems and piston skirts get lubricated. The level set is probably a tad on the high side from feed back through web pages. I totaly agree with your statement about piston slap. On a modern engine this should not exist and has not for a number of years on many engines of various brands but recently has come to the fore again where manufacturers have had a problem where possibly a supplier has engineered the piston for a specific application and f**k*d up. This again may be a quality issue with the supplier as mentioned before where they are not adhering to there own standards or the customers standards ie the vehicle manufacturer.
I would also like to point out that there are two forms of piston slap with a new engine so I'm not talking about an engine that has done high K's and is worn.
Cause - A piston that slaps has a large skirt clearance or is quite short and rocks around the gudgeon pin.
1] The piston can simply knock once every power stroke or in worse cases every stroke which will cause a loud metalic sound and go away once the engine is warmed but does not have excessive oil consumption.
2] The piston can rock in such a way as to cause the rings to flutter in the grooves. This pumps oil past the rings or they are merely are not touching the bore at all times causing oil to go past the rings to the combustion area. Such a situation will cause excess oil consumption which may or may not cause an audible knock.
The root cause is the same as in Cause above.

 

[clixanup]

Hey Guys,

Here is some interesting reading about GM Powertrain's analysis of pre-2001 LS1 engines and what they did to correct the perceived problems.

http://www.idavette.net/hib/02ls6/page5.htm

 

[Don Sutton]

Hey Guys,

Here is some interesting reading about GM Powertrain's analysis of pre-2001 LS1 engines and what they did to correct the perceived problems.

http://www.idavette.net/hib/02ls6/page5.htm

Is this Juriga a GM engineer? Interesting comment in the last paragraph about owners should ignore the knock. If it were a Toyota would they say this? I think not. If you are an owner and you are trying to sell your car and the prospective buyer comes around before you've got time to warm the engine what do you do?