View Poll Results: Poll: Have you had bore scoring on your 997.1 or 997.2 engine?
Yes, 997.1 (05-08 MY)
143
14.50%
Yes, 997.2 (09-12 MY)
18
1.83%
No, 997.1 (05-08 MY)
524
53.14%
No, 997.2 (09-12 MY)
301
30.53%
Voters: 986. You may not vote on this poll
Poll: Scored cylinder failure for your 997, Y or N? tell us (yr, 997.1 or 997.2)
09-28-2021, 05:33 PM
#466
2009 997.2 C4S
now 73,000 miles (bought as a CPO car with 20,000 miles on the clock)
daily driver, winter and summer in northern Wisconsin
had it scoped by an Indy before the CPO warranty ran out, normal
i don’t send the oil out for analysis, just change it every 7500 miles and drive the crap out of it. It’s already given me more grins than I paid for it. I just swapped out summer for winter tires today, snow comes early this far north.
now 73,000 miles (bought as a CPO car with 20,000 miles on the clock)
daily driver, winter and summer in northern Wisconsin
had it scoped by an Indy before the CPO warranty ran out, normal
i don’t send the oil out for analysis, just change it every 7500 miles and drive the crap out of it. It’s already given me more grins than I paid for it. I just swapped out summer for winter tires today, snow comes early this far north.
The following 2 users liked this post by TSP:
PhillyNate (10-07-2021),
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09-28-2021, 06:21 PM
#467
Rennlist Member
Shouldn't you be somewhere else gouging folks for their climate control switches or something?
BTW,
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advrider1967 (10-05-2021)
10-05-2021, 05:02 PM
#468
Sorry to read that but thanks for passing on the info. Since it's a 9A1 I'm curious if the scoring is on one side of the cylinder (the thrust side only like the M96/M97 engine bore scoring) or if it's on both sides. Please post some photos when you get a chance showing both sides.
There's only a small number of 9A1 scoring cases that I've seen documented and they looked like the piston siezed (scored on both sides). The failure signature is different from the earlier engine bore scoring. Interesting to see which kind this was.
Please do an LN Engineering DIY rebuild and document the process for us in a new thread! It will be a Rennlist first on a 9A1.
There's only a small number of 9A1 scoring cases that I've seen documented and they looked like the piston siezed (scored on both sides). The failure signature is different from the earlier engine bore scoring. Interesting to see which kind this was.
Please do an LN Engineering DIY rebuild and document the process for us in a new thread! It will be a Rennlist first on a 9A1.
10-05-2021, 05:03 PM
#469
10-05-2021, 05:08 PM
#470
I should probably start a new thread, but....
My own car, a 2009 C2 PDK with 64k just got a new factory engine under warranty. 5 and 6 looked like a hand grenade went off in them, all other bores looked absolutely pristine, I kid you not. I realize that whats in there now is no better than what ate itself to death, but hey, no cost to me, so who is arguing.
What is the hypothesis on #1?
10-05-2021, 05:47 PM
#472
^^not terrible, my 05 with 60k looked slightly worse from what I could tell. Heading to FSI in June.
I really don’t think the 997.2 are immune from this issue at all, I just think they are newer, less were made, and like your example some are being fixed under warranty. We just hear less about the issues, for now……..
I really don’t think the 997.2 are immune from this issue at all, I just think they are newer, less were made, and like your example some are being fixed under warranty. We just hear less about the issues, for now……..
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Lateralgrip (10-08-2021)
10-05-2021, 05:51 PM
#473
Former Vendor
^^not terrible, my 05 with 60k looked slightly worse from what I could tell. Heading to FSI in June.
I really don’t think the 997.2 are immune from this issue at all, I just think they are newer, less were made, and like your example some are being fixed under warranty. We just hear less about the issues, for now……..
I really don’t think the 997.2 are immune from this issue at all, I just think they are newer, less were made, and like your example some are being fixed under warranty. We just hear less about the issues, for now……..
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Lateralgrip (10-08-2021)
10-05-2021, 06:39 PM
#474
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Lateralgrip (10-08-2021)
10-05-2021, 08:04 PM
#475
It was fixed under A warranty, not Porsche's. If I hadnt' had the foresight to lay down five grand in the face of every assurance these are "bulletproof" Id be holding a bill for thirty grand. I work on these, so I know better, there is a lesson here.
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10-07-2021, 11:29 AM
#478
Three Wheelin'
They were all equally scored, at 12 and 6.
I should probably start a new thread, but....
My own car, a 2009 C2 PDK with 64k just got a new factory engine under warranty. 5 and 6 looked like a hand grenade went off in them, all other bores looked absolutely pristine, I kid you not. I realize that whats in there now is no better than what ate itself to death, but hey, no cost to me, so who is arguing.
What is the hypothesis on #1?
I should probably start a new thread, but....
My own car, a 2009 C2 PDK with 64k just got a new factory engine under warranty. 5 and 6 looked like a hand grenade went off in them, all other bores looked absolutely pristine, I kid you not. I realize that whats in there now is no better than what ate itself to death, but hey, no cost to me, so who is arguing.
What is the hypothesis on #1?
Baz's white paper talks about this in detail. He thinks the block casting may be unstable and can actually shrink overtime, particularly in early engines. If the piston heats up too fast in comparison to the cylinder, it gets too big (siezes) and scores both sides. This is a completely different failure mechanism than the bore scoring in M96/97 engines, and your experience supports that.
It would be good to know the engine's history, the failure examples Baz writes about are engines drive hard without proper warm-up in cold climates. It makes perfect sense as the piston has a much smaller thermal mass than the block itself and will warm up much quicker and expand faster. Don't lug the engine but 9A1 owners are well-advised to limit the RPMs to 3k until the oil is at operating temp.
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10-07-2021, 11:52 AM
#479
Rennlist Member
Interesting, they were scored on both sides (I assume that's what 12 and 6 means) so they actually siezed and did not have the typical one-sided scoring of the M96/97.
Baz's white paper talks about this in detail. He thinks the block casting may be unstable and can actually shrink overtime, particularly in early engines. If the piston heats up too fast in comparison to the cylinder, it gets too big (siezes) and scores both sides. This is a completely different failure mechanism than the bore scoring in M96/97 engines, and your experience supports that.
It would be good to know the engine's history, the failure examples Baz writes about are engines drive hard without proper warm-up in cold climates. It makes perfect sense as the piston has a much smaller thermal mass than the block itself and will warm up much quicker and expand faster. Don't lug the engine but 9A1 owners are well-advised to limit the RPMs to 3k until the oil is at operating temp.
Baz's white paper talks about this in detail. He thinks the block casting may be unstable and can actually shrink overtime, particularly in early engines. If the piston heats up too fast in comparison to the cylinder, it gets too big (siezes) and scores both sides. This is a completely different failure mechanism than the bore scoring in M96/97 engines, and your experience supports that.
It would be good to know the engine's history, the failure examples Baz writes about are engines drive hard without proper warm-up in cold climates. It makes perfect sense as the piston has a much smaller thermal mass than the block itself and will warm up much quicker and expand faster. Don't lug the engine but 9A1 owners are well-advised to limit the RPMs to 3k until the oil is at operating temp.
10-07-2021, 01:01 PM
#480
Rennlist Member
Spot on. I've seen both scoring (based on the failure of the Al-Si cylinder system common to all Alusil/Lokasil cylinders) in all bores as well as seizing as Baz has described. The factory clearances are ridiculously tight. I measured a new block and pistons at .0007" total clearance at the gauge point, so it's easy to see if there are latent stresses in the castings that allow the bores to move, why the pistons seize.