Out of Round Pistons in '01 LS1s
02-12-2002, 01:48 PM
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Re: Out of Round Pistons in '01 LS1s I think it is more a result of the rings and PCV than the pistons themselves. They have made changes to the ring type and have introduced a new PCV valve as well.
Good luck with getting it resolved.
Cheers,
Chris
Good luck with getting it resolved.
Cheers,
Chris
02-12-2002, 04:11 PM
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Re: Out of Round Pistons in '01 LS1s If you are currently in the oil consumption test and the vehicle exceeds the GM limits for the test, you will probably be asked to submit the car for a "re-ring." They had a lot of issues with 2001 Z06 Vettes and the proceedure GM introduced late last year was to test the vehicle for oil consumption, if it fails the test, GM sends a re-designed set of rings to the dealership and they are installed. Some of the Vette owners who have gone through this saw less oil consumption, but it did not cure the problem. I wonder what the "under the breath" comment about the block refers to. Remember, GM wouldn't admit any problems with the oil consumption for a long time, then the re-ring was announced but no parts where available, now some owners with the fix still see consumption.....
Some of the Vette owners with issues have switched to Royal Purple oil and said it helped dramatically. May be worth a shot, depending on what GM says and does for you. Don't let the issue die if they say the oil consumption does not exceed their limit. Continue to push the service department for a fix and check into state lemon law requirements.
Todd
Some of the Vette owners with issues have switched to Royal Purple oil and said it helped dramatically. May be worth a shot, depending on what GM says and does for you. Don't let the issue die if they say the oil consumption does not exceed their limit. Continue to push the service department for a fix and check into state lemon law requirements.
Todd
02-12-2002, 07:02 PM
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Re: Out of Round Pistons in '01 LS1s Thanks all! I will definitely keep the re-ring results you mentioned when we get to that point (Sunday we're turning it in). I just hope they own up to it. It's pretty crappy when you design something and don't stand up and take on the chin like a responsible person. I will definitely not back off of them on this. I really don't want to have to rebiuld just to fix their engineer's hair brained idea that out of round pistons is a good thing.
Thanks,
Eddie <img src="gr_stretch.gif" border="0">
Thanks,
Eddie <img src="gr_stretch.gif" border="0">
02-13-2002, 12:49 AM
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Out of Round Pistons in '01 LS1s What do you guys think about out of round pistons?
What is the worst that could result?
The September before last I bought a '01 WS6. Everything seemed to be great with the car and I have a lot of fun in it. I have documented a basic weekly maintenance check that I do every weekend. After having about a year’s time to trend the data, it turns out that the car is burning about 1 qt. every 1K miles. This is just regular speed limit type driving, no racing, etc., with an occasional (daily) 1-3rd run.
A couple of months ago I noticed a slight tick in the front of both heads. Couldn't tell if it was lifter or valve noise so I had the dealership check it out. When I picked the car up the rep said that the engine noise was normal but the oil consumption was not, so they put the car on an Oil Consumption Test. Basically, document the oil, mileage and driving type (city/hwy) at each fill-up (five minute cool down from operating temp). After I mentioned that I had come to understand that a large percentage of the '01 LS1 blocks had out of round pistons, she confessed that someone from GM had come down and explained that they had replaced/rebuilt too many of these "faulty" blocks that they were now imposing the Oil Consumption Test. Under her breath she mentioned a new block.?
I just completed the 12th and last entry and am about to go back to the dealer to turn it all back in.
What do you guys think?
My thoughts:
1) If the noise is from out of round pistons
2) Out of round pistons equals some amount of blow-by
3) I'm losing oil at an accelerated rate
The oil is burning in the combustion chamber, right?
Problems:
Blow-by results in compression loss
If the oil's burning in the combustion chamber and the pistons are out of round, what about damage to the rings, bore, combustion chamber, valve surfaces, bore surfaces, spark, exhaust?
What is the maximum impact you guys can theorize would result from out of round pistons?
If these guys are going to replace my block, I want to know how much more this could really affect.
And if they don't, I'll have something to argue with.
If you read all this, thanks!
Eddie
What is the worst that could result?
The September before last I bought a '01 WS6. Everything seemed to be great with the car and I have a lot of fun in it. I have documented a basic weekly maintenance check that I do every weekend. After having about a year’s time to trend the data, it turns out that the car is burning about 1 qt. every 1K miles. This is just regular speed limit type driving, no racing, etc., with an occasional (daily) 1-3rd run.
A couple of months ago I noticed a slight tick in the front of both heads. Couldn't tell if it was lifter or valve noise so I had the dealership check it out. When I picked the car up the rep said that the engine noise was normal but the oil consumption was not, so they put the car on an Oil Consumption Test. Basically, document the oil, mileage and driving type (city/hwy) at each fill-up (five minute cool down from operating temp). After I mentioned that I had come to understand that a large percentage of the '01 LS1 blocks had out of round pistons, she confessed that someone from GM had come down and explained that they had replaced/rebuilt too many of these "faulty" blocks that they were now imposing the Oil Consumption Test. Under her breath she mentioned a new block.?
I just completed the 12th and last entry and am about to go back to the dealer to turn it all back in.
What do you guys think?
My thoughts:
1) If the noise is from out of round pistons
2) Out of round pistons equals some amount of blow-by
3) I'm losing oil at an accelerated rate
The oil is burning in the combustion chamber, right?
Problems:
Blow-by results in compression loss
If the oil's burning in the combustion chamber and the pistons are out of round, what about damage to the rings, bore, combustion chamber, valve surfaces, bore surfaces, spark, exhaust?
What is the maximum impact you guys can theorize would result from out of round pistons?
If these guys are going to replace my block, I want to know how much more this could really affect.
And if they don't, I'll have something to argue with.
If you read all this, thanks!
Eddie