Dreaded Bore scoring on 06 C2S
05-07-2022, 02:44 PM
#31
Rennlist Member
Background: Bought 06 911 C2S in August of 2021, 50K miles. Have put on 6K since then.
First 3-4K miles went pretty flawless, no indications of engine issues. I gradually started seeing increased oil consumption, starting at 1 quart every 1K miles or so. Also saw some sootiness on driver's side exhaust, no unusual noises though. Last weekend I went to HPDE and the car went through 1 quart from when I changed the oil on Thursday to the end of the first day on Saturday, maybe 150 miles. Not leaking underneath. It started throwing P0301 codes indicating misfires on cylinder 1, so I shut it down when it started flashing. Karl @ RennsportKC scoped Cylinder 1 and advised I'll need a rebuild/new engine due to bore scoring. Said that I may not need it immediately but given the oil consumption I can't imagine I can keep driving it, at least not without destroying the new Soul sport cats when it's eating so much oil.
He's certified with Jake @ FSI, but I spoke with Jakes and realistically I'm looking at the end of 2023. He will have 8 engines available January-July but he says he's turned down 90 customers so demand will be high. And it would be a stage 2 costing at least 35K ("wild guess"). What are my best other options, I see Vision Motorsports in CA. Anyone know of a shop relatively close to KC that can handle this and what the current (supply shortage) pricing would be on a 3.8 rebuild? And how much extra it would be to go 4 or 4.2?
First 3-4K miles went pretty flawless, no indications of engine issues. I gradually started seeing increased oil consumption, starting at 1 quart every 1K miles or so. Also saw some sootiness on driver's side exhaust, no unusual noises though. Last weekend I went to HPDE and the car went through 1 quart from when I changed the oil on Thursday to the end of the first day on Saturday, maybe 150 miles. Not leaking underneath. It started throwing P0301 codes indicating misfires on cylinder 1, so I shut it down when it started flashing. Karl @ RennsportKC scoped Cylinder 1 and advised I'll need a rebuild/new engine due to bore scoring. Said that I may not need it immediately but given the oil consumption I can't imagine I can keep driving it, at least not without destroying the new Soul sport cats when it's eating so much oil.
He's certified with Jake @ FSI, but I spoke with Jakes and realistically I'm looking at the end of 2023. He will have 8 engines available January-July but he says he's turned down 90 customers so demand will be high. And it would be a stage 2 costing at least 35K ("wild guess"). What are my best other options, I see Vision Motorsports in CA. Anyone know of a shop relatively close to KC that can handle this and what the current (supply shortage) pricing would be on a 3.8 rebuild? And how much extra it would be to go 4 or 4.2?
05-07-2022, 03:07 PM
#32
Seeing more and more 997.1 cars with bore scoring issues..and its the worst time to have this problem due to part shortages!! Just curious if Porsche ever dealt with this major issue as it isn't fair to owners even with low miles on them and driven properly. I heard if you don't drive the car much this is one of the reason too. So I am sure a lot of collectors out there might have this issue and not know it. Dishing out $25-40K to fix this problem is not cool at all when you just want to enjoy your 997 and have fun driving it.
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Robocop305 (05-13-2022)
05-07-2022, 04:25 PM
#33
Probably a 4.0 conversion. Just need to see if I can do that reasonably priced. This isn't my daily driver so if I need to wait 6 months that's fine.
05-08-2022, 09:36 AM
#34
Rennlist Member
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groovzilla (10-09-2022)
05-09-2022, 03:58 AM
#35
Nordschleife Master
That is probably the least expensive way to address for sure. Probably makes sense if you don’t want to own the car for a long time. If you do, it’s harder to contemplate the possibility of dealing w/ the issue again in the future. That’s when the extra $’s for a rebuild start making sense.
05-09-2022, 07:46 AM
#36
Rennlist Member
Yeah but there will be records of that engine replacement. And even if the owner doesn't plan on keeping the car for a long time but just looking for the least expensive fix, it's hard to imagine that solution wouldn't affect resale value. Some buyers wouldn't even consider a 997 with a salvage engine unless perfect and reliable history of it. And even that may not be enough for some.
- Source a used engine in good condition - issues are bore scoring can happen again and resale value below that of car w/ original engine; upsides are that the resale value is likely to be higher than selling a car w/ a bore scored engine and potentially the time to get the project completed)
- rebuild engine w/ LN nickies - issues are again potential impact to resale value (compared to a similar example w/o bore scoring), time to get the car back on the road; upsides are that you solve the bore scoring problem for good and hopefully there are many reputable shops around the country that can perform a “stocker” build. It may not have the FSI cachet but it will likely serve the owner really well for a very long time.
- Go all out for a FSI or Hartec rebuild - downside are potential the time to get access to the completed project and/or time w/o the car (FSI backlog according to Rennvision videos has been consistently 9+ months for many years), cost as this is probably the most expensive option; upsides are potentially maximizing the performance improvements associated w/ a rebuild by these specialty shops (given their experience building high performance engines), probably higher resale value and an engine that will probably last forever if taken care of properly.
I left out the “hot potato” scenario, not really an option for a lot of people to knowingly pass this kind of problem on to another enthusiast. Some might, I really couldn’t and won’t.
I would also say that, given all the rumblings about parts shortages, if I were looking to buy a 997.1 right now I’d really only do it with a proper bore scope. If a prospective buyer doesn’t have the opportunity to do that or can’t, they should buy a 997.2. I can’t imagine buying a non-turbo, non-GT3 997.1 on an auction site right now as most don’t ever provide bore scopes.
Last edited by 8KaboveMSL; 05-09-2022 at 07:48 AM.
05-09-2022, 10:59 AM
#37
Burning Brakes
OP put heart & soul into the car and modded it exactly how he wanted it; I think he is in it for the long haul..good luck! 
05-09-2022, 01:08 PM
#38
Rennlist Member
I don’t think a replacement engine will bring down the value all that much as long as it is well documented. Let’s face it as much as we love these 997.1’s if it isn’t a Turbo(S), GT3, GT2 it’s not gonna be a collectible where numbers matching engine etc is gonna really matter. I do believe they will be very desirable to enthusiast drivers and be in demand more and more as time goes on. That is why I decided on getting the FSI 4.0 stage II. My car is a driver, not some garage queen. I never intend to sell my 911 I will always have it and I will just add a car instead of replacing the 911. I do know that with and FSI engine it permanently fixes the all weak points in the m97 and I will get an engine that will not only be a 4L power house but extremely reliable as well. The bonus is if I ever do sell, I believe that it may make my 911 more valuable having an FSI 4.0 Stage II IMO. So The question is, do you love this car? and is it a forever car that will always be in your fleet? If the answer is an enthusiastic YES, then you know what you should do.
Goodluck, it’s was at first tough deciding what to do, but then became an easy one after asking my self the same questions above.
Goodluck, it’s was at first tough deciding what to do, but then became an easy one after asking my self the same questions above.
Last edited by Scalp_em; 05-09-2022 at 01:14 PM.
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05-09-2022, 06:41 PM
#39
That’s a really fair point. Seems like the options from least to most expensive:
I left out the “hot potato” scenario, not really an option for a lot of people to knowingly pass this kind of problem on to another enthusiast. Some might, I really couldn’t and won’t.
I would also say that, given all the rumblings about parts shortages, if I were looking to buy a 997.1 right now I’d really only do it with a proper bore scope. If a prospective buyer doesn’t have the opportunity to do that or can’t, they should buy a 997.2. I can’t imagine buying a non-turbo, non-GT3 997.1 on an auction site right now as most don’t ever provide bore scopes.
- Source a used engine in good condition - issues are bore scoring can happen again and resale value below that of car w/ original engine; upsides are that the resale value is likely to be higher than selling a car w/ a bore scored engine and potentially the time to get the project completed)
- rebuild engine w/ LN nickies - issues are again potential impact to resale value (compared to a similar example w/o bore scoring), time to get the car back on the road; upsides are that you solve the bore scoring problem for good and hopefully there are many reputable shops around the country that can perform a “stocker” build. It may not have the FSI cachet but it will likely serve the owner really well for a very long time.
- Go all out for a FSI or Hartec rebuild - downside are potential the time to get access to the completed project and/or time w/o the car (FSI backlog according to Rennvision videos has been consistently 9+ months for many years), cost as this is probably the most expensive option; upsides are potentially maximizing the performance improvements associated w/ a rebuild by these specialty shops (given their experience building high performance engines), probably higher resale value and an engine that will probably last forever if taken care of properly.
I left out the “hot potato” scenario, not really an option for a lot of people to knowingly pass this kind of problem on to another enthusiast. Some might, I really couldn’t and won’t.
I would also say that, given all the rumblings about parts shortages, if I were looking to buy a 997.1 right now I’d really only do it with a proper bore scope. If a prospective buyer doesn’t have the opportunity to do that or can’t, they should buy a 997.2. I can’t imagine buying a non-turbo, non-GT3 997.1 on an auction site right now as most don’t ever provide bore scopes.
05-09-2022, 06:59 PM
#40
Rennlist Member
Agree with your statement that who ever is selling their 997.1 should come with a bore scope report so the buyer is well aware of the current conditions. Also, IMS bearing is another huge issue for the 997.1 generation. Is there a way to find out if there are potential issues there? Can a PPI identify potential IMS Bearing issues? I now that would be another thread on its own.
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Ed99 (05-10-2022)
05-09-2022, 10:45 PM
#41
RL Community Team
Rennlist Member
Rennlist Member
Actually, it's not. Only the early build 05s that used the smaller single row bearings of the later 996 M96 motors is a concern. Any 997.1s from mid 05 through 08 have the larger single row bearing that hardly ever fails and the few failures were on track with sustained high rpm running where the bearing surface speed exceeds it's design spec at the high RPMs.
05-10-2022, 04:14 AM
#43
Nordschleife Master
That’s a really fair point. Seems like the options from least to most expensive:
I left out the “hot potato” scenario, not really an option for a lot of people to knowingly pass this kind of problem on to another enthusiast. Some might, I really couldn’t and won’t.
I would also say that, given all the rumblings about parts shortages, if I were looking to buy a 997.1 right now I’d really only do it with a proper bore scope. If a prospective buyer doesn’t have the opportunity to do that or can’t, they should buy a 997.2. I can’t imagine buying a non-turbo, non-GT3 997.1 on an auction site right now as most don’t ever provide bore scopes.
- Source a used engine in good condition - issues are bore scoring can happen again and resale value below that of car w/ original engine; upsides are that the resale value is likely to be higher than selling a car w/ a bore scored engine and potentially the time to get the project completed)
- rebuild engine w/ LN nickies - issues are again potential impact to resale value (compared to a similar example w/o bore scoring), time to get the car back on the road; upsides are that you solve the bore scoring problem for good and hopefully there are many reputable shops around the country that can perform a “stocker” build. It may not have the FSI cachet but it will likely serve the owner really well for a very long time.
- Go all out for a FSI or Hartec rebuild - downside are potential the time to get access to the completed project and/or time w/o the car (FSI backlog according to Rennvision videos has been consistently 9+ months for many years), cost as this is probably the most expensive option; upsides are potentially maximizing the performance improvements associated w/ a rebuild by these specialty shops (given their experience building high performance engines), probably higher resale value and an engine that will probably last forever if taken care of properly.
I left out the “hot potato” scenario, not really an option for a lot of people to knowingly pass this kind of problem on to another enthusiast. Some might, I really couldn’t and won’t.
I would also say that, given all the rumblings about parts shortages, if I were looking to buy a 997.1 right now I’d really only do it with a proper bore scope. If a prospective buyer doesn’t have the opportunity to do that or can’t, they should buy a 997.2. I can’t imagine buying a non-turbo, non-GT3 997.1 on an auction site right now as most don’t ever provide bore scopes.
I think I would go to the least expensive reputable rebuild shop rather than sourcing a used engine from somewhere which could be the start of other issues. And I would definitely not go all out with a 4.0 rebuild if the plan is to sell once repaired. Most buyers don't know the difference between 3.8 and 4.0 and even if educated I doubt none but very few would pay a premium for it.
05-10-2022, 01:24 PM
#44
I am not sure what their current backlog is or cost, but you may want to reach out to https://www.blackforestracing.com/
They have done some work for me on my 08 C4S and I know they have done some rebuilds here locally as well. Very knowledgeable crew and some really cool projects in the shop at all times.
Cheers,
Eric
They have done some work for me on my 08 C4S and I know they have done some rebuilds here locally as well. Very knowledgeable crew and some really cool projects in the shop at all times.
Cheers,
Eric
05-10-2022, 02:43 PM
#45
Rennlist Member
Regarding bore scoring diagnosis, if one does a from-the-bottom borescope inspection, can one also wriggle their hand up into the bottom of the bore(s) to try to determine how deep the scoring is with one's fingernail (I think Jake has described "if it doesn't catch a fingernail then it's not scoring just scuffing".)?