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)
#241
Rennlist Member
[QUOTE=Charles Navarro;16066031]
Yes, bore scoring is typically limited to bank 2 (cylinder 4-6), however all 3.4, 3.6, and 3.8 models are equally susceptible to bore scoring. Base models, and the 3.2 Boxster S, don't seem to score. They use a KS cast piston where the other models use a forged Mahle piston. The iron clad coatings are also different between manufacturer of piston, and the KS coating is much more durable. Once the coating fails on the piston skirt, it's all over.
06-08 IMS bearing failures, although rare, do happen. My guess is that it's just a matter of time as the original bearings age, failures will be more common as the bearing exceeds its L10 life.
Thanks for that, I just spent the last 20 minutes trying to find that article that I came upon this morning by accident, and frustratingly can't seem to find it again. But thanks for your input.
Yes, bore scoring is typically limited to bank 2 (cylinder 4-6), however all 3.4, 3.6, and 3.8 models are equally susceptible to bore scoring. Base models, and the 3.2 Boxster S, don't seem to score. They use a KS cast piston where the other models use a forged Mahle piston. The iron clad coatings are also different between manufacturer of piston, and the KS coating is much more durable. Once the coating fails on the piston skirt, it's all over.
06-08 IMS bearing failures, although rare, do happen. My guess is that it's just a matter of time as the original bearings age, failures will be more common as the bearing exceeds its L10 life.
#242
Advanced
No Bore Scoring found.
I recently purchased a 2007 997.1 4S with 43k miles (manual trans). I had a PPI done before purchasing the car and also had a bore scope done. Everything checked out good (I saw the pictures and am waiting for the shop to email them to me).
In the 3 weeks of ownership I've put on nearly 600 miles and it's been a pleasure to drive. No leaks, squeaks or rattles. And I make sure to short shift (~3k RPMs) until oil temp reaches 200F (I can only hope/guess that the previous owners did the same?).
I recently purchased a 2007 997.1 4S with 43k miles (manual trans). I had a PPI done before purchasing the car and also had a bore scope done. Everything checked out good (I saw the pictures and am waiting for the shop to email them to me).
In the 3 weeks of ownership I've put on nearly 600 miles and it's been a pleasure to drive. No leaks, squeaks or rattles. And I make sure to short shift (~3k RPMs) until oil temp reaches 200F (I can only hope/guess that the previous owners did the same?).
Last edited by FamilyMan928; 08-28-2019 at 12:14 PM.
#243
Charles -Base models (911) have the 3.6 and in your next sentence you say "base models do not score" - assuming you are referring only to base model Boxsters? I guess I am answering my own question. Thanks.
#244
Instructor
So having read this thread, I am not sure if:
Willing to jump in on this if I think I can reasonably reduce the risk - but numbers like 12% affected and climbing have me thinking about a TT instead
Can anyone clarify please?
- there is anything to do to prevent bore scoring (low temp thermostat, oil changes?)
- Lower or higher mileage cars are affected more - the theory that a car regularly driven might be better even in a cold climate?
- 3.6 vs 3.8 more prone- Ive seen references to both here and other threads
Willing to jump in on this if I think I can reasonably reduce the risk - but numbers like 12% affected and climbing have me thinking about a TT instead
Can anyone clarify please?
#245
Rennlist Member
And Cayman. I've never seen a 2.5 or 2.7 engine get scored bores. Same goes for the 3.2 Boxster which also received cast pistons, which again, don't seem to have the piston skirt coating failures that end up with scored bores.
#246
Rennlist Member
So having read this thread, I am not sure if:
Willing to jump in on this if I think I can reasonably reduce the risk - but numbers like 12% affected and climbing have me thinking about a TT instead
Can anyone clarify please?
- there is anything to do to prevent bore scoring (low temp thermostat, oil changes?)
- Lower or higher mileage cars are affected more - the theory that a car regularly driven might be better even in a cold climate?
- 3.6 vs 3.8 more prone- Ive seen references to both here and other threads
Willing to jump in on this if I think I can reasonably reduce the risk - but numbers like 12% affected and climbing have me thinking about a TT instead
Can anyone clarify please?
For sure, I'd make sure to bore scope the engine with piston as TDC as Jake has advised in his Rennvision series.
Based of the available research, higher ZDDP levels and Moly levels can help extend the life of Alusil and Lokasil bores.
All models with forged pistons are equally susceptible to scoring.
#247
Rennlist Member
I've watched most if not all the videos and it seems most of this applies to the previous generation of engines.
#248
Former Vendor
My current videos do not pertain to the 9a1 engine. The process is different, and much more difficult to approach from inside the oil sump, right now for the general shop, and enthusiast a spark plug accessed inspection is the only choice. With that, you are only seeing 1/2 the picture, but in some advanced cases of scoring, that's enough to prove that scoring exists.
#249
Rennlist Member
My current videos do not pertain to the 9a1 engine. The process is different, and much more difficult to approach from inside the oil sump, right now for the general shop, and enthusiast a spark plug accessed inspection is the only choice. With that, you are only seeing 1/2 the picture, but in some advanced cases of scoring, that's enough to prove that scoring exists.
#250
Former Vendor
We have seen scoring on all cylinders with the 9a1 at some point. The most prominent is #1, but that doesn't mean that any other cylinder should be discounted.
Start on #1, and if you find scoring, there's no need to go further, but if you don't find it on #1, then scope the entire engine. It may still exist, because bottom access to the under side of the cylinders is so difficult to achieve, and requires medical grade tools to perform. There's also the risk of breaking the camera inside the engine.
Start on #1, and if you find scoring, there's no need to go further, but if you don't find it on #1, then scope the entire engine. It may still exist, because bottom access to the under side of the cylinders is so difficult to achieve, and requires medical grade tools to perform. There's also the risk of breaking the camera inside the engine.
#251
Rennlist Member
We have seen scoring on all cylinders with the 9a1 at some point. The most prominent is #1, but that doesn't mean that any other cylinder should be discounted.
Start on #1, and if you find scoring, there's no need to go further, but if you don't find it on #1, then scope the entire engine. It may still exist, because bottom access to the under side of the cylinders is so difficult to achieve, and requires medical grade tools to perform. There's also the risk of breaking the camera inside the engine.
Start on #1, and if you find scoring, there's no need to go further, but if you don't find it on #1, then scope the entire engine. It may still exist, because bottom access to the under side of the cylinders is so difficult to achieve, and requires medical grade tools to perform. There's also the risk of breaking the camera inside the engine.
Thanks again. Much appreciated.
#253
Rennlist Member
Thanks, I'll take you up on that. Could be educational for everyone. It will be a few weeks before I can. Out of town purchase so I'm still trying to find the right provider in Houston. One told me pulling a DME is enough. No check engine light, no problem then. We all know that's not true. Doesn't inspire confidence. Other shops flat out won't do PPI 's. I'll probably post something about this on another thread to keep this on topic.