991/997 Engine reliability coming from BMW
10-20-2018, 01:43 PM
#1
991/997 Engine reliability coming from BMW
Hi there!
So I have made my first step into Porsche, I have left the comfort of the bimmerforums.
My story; I have been a big fan of BMW, my father bought me my first, a rusted out e36 which at the time was already a 15 year old car. Since then I was a fan of natural aspiration. So over time I had 3 E46 (328i, 330i wagon, 330ci) and 2 E92's (335i and M3).
And now that I have had my fantastic E92 M3 (NA V8, DCT, 420HP) it is time for a change. I want a manual (dct is fantastic, but I still have more fun in my DD e46 manual), RWD sports car without turbos. And I frankly have started to detest BMW both as a company and brand. (introduction of 2 series active tourer and M/// branding for 16 year old's which is frankly infantile).
Lastly I want a car that has a close to perfect when it comes to the engine. Case and point, my E92 M3 has a NA V8 (designation S65) derived from a V10 used in BMW's Sauber racing program, there is the infamous rod bearing issue, while my E92 has only 70tkm, I have been dreading the moment something would happen.
So to the point, how is the reliability of the engines in the following cars;
997 2008+ C2S / GTS
991 C2S
Thanks in advance / danke im Voraus!
So I have made my first step into Porsche, I have left the comfort of the bimmerforums.
My story; I have been a big fan of BMW, my father bought me my first, a rusted out e36 which at the time was already a 15 year old car. Since then I was a fan of natural aspiration. So over time I had 3 E46 (328i, 330i wagon, 330ci) and 2 E92's (335i and M3).
And now that I have had my fantastic E92 M3 (NA V8, DCT, 420HP) it is time for a change. I want a manual (dct is fantastic, but I still have more fun in my DD e46 manual), RWD sports car without turbos. And I frankly have started to detest BMW both as a company and brand. (introduction of 2 series active tourer and M/// branding for 16 year old's which is frankly infantile).
Lastly I want a car that has a close to perfect when it comes to the engine. Case and point, my E92 M3 has a NA V8 (designation S65) derived from a V10 used in BMW's Sauber racing program, there is the infamous rod bearing issue, while my E92 has only 70tkm, I have been dreading the moment something would happen.
So to the point, how is the reliability of the engines in the following cars;
997 2008+ C2S / GTS
991 C2S
Thanks in advance / danke im Voraus!
10-20-2018, 03:20 PM
#2
Intermediate
I moved from e92 M3 ZCP DCT to 991 C2S PDK. I've only had the 911 for a couple months but so far so good. Cars drive similar in that all the good sounds and power are up in the RPM range. One of the most noticeable differences is grip. 911 has much better grip to the rear wheels than my old M3. I imagine this is attributed to engine sitting over the rear axles. I imagine the 3.8 liter flat 6 is probably more reliable than the S65. I don't hear horror stories such as rod bearings and throttle actuators about the 3.8 as I did the S65. I'm sure the flat 6 has it's own issues but not nearly as publicized as rod bearings and throttle actuators for the M3.
10-20-2018, 03:32 PM
#3
Rennlist Member
Porsche is no different than BMW when it comes to each model having an Achilles Heel type of failure possibility. If you want bulletproof, don’t go with either BMW or Porsche.
1952-1959 356 - Insufficient cooling - later models had larger oil cooler
1974-1977 911s - Emissions issues/Weak head studs - Resulting in engine rebuild
911sc - Continued poor head stud design resulting in engine rebuild
1985-1987 911 Carrera - Poor valve guides resulting in major oil consumption/ top end rebuild.
1989-1992 964 - No engine seal leading to major oil leaks/engine resulting in reseal
1995-1998 993 - Clogged air passages in heads - Resulting in top end rebuild
1999-2004 996 - Weak IMS Bearing - Resulting in replacement or engine rebuild due to catastrophic failure
2005-2006 997 - Weak IMS Bearing - " " "
2005-2008 997 - Weak cylinder walls leading to Bore Scoring/Major oil consumption/Engine rebuild.
That said, Porsche is still pretty reliable, and the 997s that have the larger IMS bearing are probably fine.
1952-1959 356 - Insufficient cooling - later models had larger oil cooler
1974-1977 911s - Emissions issues/Weak head studs - Resulting in engine rebuild
911sc - Continued poor head stud design resulting in engine rebuild
1985-1987 911 Carrera - Poor valve guides resulting in major oil consumption/ top end rebuild.
1989-1992 964 - No engine seal leading to major oil leaks/engine resulting in reseal
1995-1998 993 - Clogged air passages in heads - Resulting in top end rebuild
1999-2004 996 - Weak IMS Bearing - Resulting in replacement or engine rebuild due to catastrophic failure
2005-2006 997 - Weak IMS Bearing - " " "
2005-2008 997 - Weak cylinder walls leading to Bore Scoring/Major oil consumption/Engine rebuild.
That said, Porsche is still pretty reliable, and the 997s that have the larger IMS bearing are probably fine.
10-20-2018, 04:44 PM
#4
Burning Brakes
In my experience 911s (I am on my 4-th) are way more reliable than BMWs. That said BMW engines were reliable for me too. It was electricals and some body parts (locks/actuators) I was not happy with.
As for the models you mentioned. Early 997 (till 2006) had smaller intermediate shaft bearings and were fault prone. Then after 2006 they changed IMS bearing size which helped the issue on that M97 engine model. 997.2 were new 9A1 engine which I believe is very reliable.
As for the models you mentioned. Early 997 (till 2006) had smaller intermediate shaft bearings and were fault prone. Then after 2006 they changed IMS bearing size which helped the issue on that M97 engine model. 997.2 were new 9A1 engine which I believe is very reliable.
Last edited by Papa Fittig; 10-20-2018 at 11:36 PM.
10-20-2018, 05:57 PM
#5
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10-20-2018, 09:27 PM
#7
Rennlist Member
Welcome to the light side. You're not the only one who loved BMW but has moved over to Porsche...
Sounds like you want a 2009-on 997 or 991.1. MY 2008 was the last of the "dreaded" non-Mezger flat six. Having lived with two highly reliable non-Mezger 986 cars for 2-3 years each and now four of the 9A1/9A2 engine cars, I think the risk factors with the earlier cars is overblown. Our first one, a 1999 986 (supposedly the worst of all) was stone reliable between the 40,000-mile marker when we bought it and 100,000 miles, when we sold it. Today, it has 220,000 miles on the original engine—which required a new RMS at 27,000 miles—in the care of my brother. Still sounds great, and pulls beautifully. Then again, the consequences are nasty if you get stung.
Ergo...I'd look for a 2009-on 997.2 or 991.1 if you want an NA flat six that, while not bulletproof (what truly is?), has shown an enviable record of reliability. Of those, a 997.2 GTS with a 6MT and the standard GTS suspension would be my first choice. That was a very special car.
Sounds like you want a 2009-on 997 or 991.1. MY 2008 was the last of the "dreaded" non-Mezger flat six. Having lived with two highly reliable non-Mezger 986 cars for 2-3 years each and now four of the 9A1/9A2 engine cars, I think the risk factors with the earlier cars is overblown. Our first one, a 1999 986 (supposedly the worst of all) was stone reliable between the 40,000-mile marker when we bought it and 100,000 miles, when we sold it. Today, it has 220,000 miles on the original engine—which required a new RMS at 27,000 miles—in the care of my brother. Still sounds great, and pulls beautifully. Then again, the consequences are nasty if you get stung.
Ergo...I'd look for a 2009-on 997.2 or 991.1 if you want an NA flat six that, while not bulletproof (what truly is?), has shown an enviable record of reliability. Of those, a 997.2 GTS with a 6MT and the standard GTS suspension would be my first choice. That was a very special car.
Last edited by stout; 10-20-2018 at 11:57 PM.
Trending Topics
10-20-2018, 09:50 PM
#8
Rennlist Member
"What I like about the 911 is that it is all things to all people. Race car and Boulevard cruiser. A commuter and grand tourer. A trophy. A toy. A piece of art. It's both flashy and discrete. You can haul kids, haul skis, or haul ***." - me (Hula)
Hula, I really like your tag line. I have checked almost all those boxes with 911s, and look forward to more.
Hula, I really like your tag line. I have checked almost all those boxes with 911s, and look forward to more.
10-20-2018, 11:10 PM
#9
Rennlist Member
a 1999 986 (supposedly the worst of all) was stone reliable between the 40,000-mile marker when we bought it and 100,000 miles, when we sold it. Today, it has 220,000 miles on the original engine—which required a new RMS at 27,000 miles—in the care of my brother. Still sounds great, and pulls beautifully.
10-21-2018, 05:22 AM
#10
Firstly, thank you all so much for your responses! :-) 
A poll,please answer with a sentence :-).
Q1: Naturally the 997.2 GTS and 991 C2S are great but which one would you choose?
Q2: 997.2 C2S or 991.1 C2 non s, the reason I think the C2 non S is great is because of the 7500 rpm redline.
Curious to hear your answers.
Good to hear that you made the exact move and are satisfied, with regards to grip, to be honest it is not a big surprise I always had that issue. As it was not my daily driver I was one of the people who had all season tires as I did not want to go through the annual ordeal. Nonetheless the continentals are good.
Well so far I have heard only good things about the 3.8, I also believe the 2S manuals to be a semi-decent investment as I do not think they will lose much value.
Thanks, I see that I should focus on getting a 2009+ engine and I should be fine.
I also only had good experiences with BMW engines, specifically the M54. I have a 330ci with M54 that just crossed the 300tkm mark and (knock on wood) nothing wrong. I need to research the 9A1 engine :-).
Thanks!
Haha, yes true!
Are the engines in the 997.2 and 991.1 3.8's mezgers? Also you mention the 997.2 GTS as a special car, I mean it represents a great balance between GT and non-GT 911's, however it is a C2S with upgrades and power kit, is there something I am missing?
Fully agree with the tag line, fantastic! 
A poll,please answer with a sentence :-).
Q1: Naturally the 997.2 GTS and 991 C2S are great but which one would you choose?
Q2: 997.2 C2S or 991.1 C2 non s, the reason I think the C2 non S is great is because of the 7500 rpm redline.
Curious to hear your answers.
I moved from e92 M3 ZCP DCT to 991 C2S PDK. I've only had the 911 for a couple months but so far so good. Cars drive similar in that all the good sounds and power are up in the RPM range. One of the most noticeable differences is grip. 911 has much better grip to the rear wheels than my old M3. I imagine this is attributed to engine sitting over the rear axles. I imagine the 3.8 liter flat 6 is probably more reliable than the S65. I don't hear horror stories such as rod bearings and throttle actuators about the 3.8 as I did the S65. I'm sure the flat 6 has it's own issues but not nearly as publicized as rod bearings and throttle actuators for the M3.
Well so far I have heard only good things about the 3.8, I also believe the 2S manuals to be a semi-decent investment as I do not think they will lose much value.
Porsche is no different than BMW when it comes to each model having an Achilles Heel type of failure possibility. If you want bulletproof, don’t go with either BMW or Porsche.
1952-1959 356 - Insufficient cooling - later models had larger oil cooler
1974-1977 911s - Emissions issues/Weak head studs - Resulting in engine rebuild
911sc - Continued poor head stud design resulting in engine rebuild
1985-1987 911 Carrera - Poor valve guides resulting in major oil consumption/ top end rebuild.
1989-1992 964 - No engine seal leading to major oil leaks/engine resulting in reseal
1995-1998 993 - Clogged air passages in heads - Resulting in top end rebuild
1999-2004 996 - Weak IMS Bearing - Resulting in replacement or engine rebuild due to catastrophic failure
2005-2006 997 - Weak IMS Bearing - " " "
2005-2008 997 - Weak cylinder walls leading to Bore Scoring/Major oil consumption/Engine rebuild.
That said, Porsche is still pretty reliable, and the 997s that have the larger IMS bearing are probably fine.
1952-1959 356 - Insufficient cooling - later models had larger oil cooler
1974-1977 911s - Emissions issues/Weak head studs - Resulting in engine rebuild
911sc - Continued poor head stud design resulting in engine rebuild
1985-1987 911 Carrera - Poor valve guides resulting in major oil consumption/ top end rebuild.
1989-1992 964 - No engine seal leading to major oil leaks/engine resulting in reseal
1995-1998 993 - Clogged air passages in heads - Resulting in top end rebuild
1999-2004 996 - Weak IMS Bearing - Resulting in replacement or engine rebuild due to catastrophic failure
2005-2006 997 - Weak IMS Bearing - " " "
2005-2008 997 - Weak cylinder walls leading to Bore Scoring/Major oil consumption/Engine rebuild.
That said, Porsche is still pretty reliable, and the 997s that have the larger IMS bearing are probably fine.
In my experience 911s (I am on my 4-th) are way more reliable than BMWs. That said BMW engines were reliable for me too. It was electricals and some body parts (locks/actuators) I was not happy with.
As for the models you mentioned. Early 997 (till 2006) had smaller intermediate shaft bearings and were fault prone. Then after 2006 they changed IMS bearing size which helped the issue on that M97 engine model. 997.2 were new 9A1 engine which I believe is very reliable.
As for the models you mentioned. Early 997 (till 2006) had smaller intermediate shaft bearings and were fault prone. Then after 2006 they changed IMS bearing size which helped the issue on that M97 engine model. 997.2 were new 9A1 engine which I believe is very reliable.
And,
https://nnjr-pca.com/9a1-engine/
Porsche finally had stacks of cash from the Cayenne and a good chunk went into the 9A1 development.
https://nnjr-pca.com/9a1-engine/
Porsche finally had stacks of cash from the Cayenne and a good chunk went into the 9A1 development.
Welcome to the light side. You're not the only one who loved BMW but has moved over to Porsche...
Sounds like you want a 2009-on 997 or 991.1. MY 2008 was the last of the "dreaded" non-Mezger flat six. Having lived with two highly reliable non-Mezger 986 cars for 2-3 years each and now four of the 9A1/9A2 engine cars, I think the risk factors with the earlier cars is overblown. Our first one, a 1999 986 (supposedly the worst of all) was stone reliable between the 40,000-mile marker when we bought it and 100,000 miles, when we sold it. Today, it has 220,000 miles on the original engine—which required a new RMS at 27,000 miles—in the care of my brother. Still sounds great, and pulls beautifully. Then again, the consequences are nasty if you get stung.
Ergo...I'd look for a 2009-on 997.2 or 991.1 if you want an NA flat six that, while not bulletproof (what truly is?), has shown an enviable record of reliability. Of those, a 997.2 GTS with a 6MT and the standard GTS suspension would be my first choice. That was a very special car.
Sounds like you want a 2009-on 997 or 991.1. MY 2008 was the last of the "dreaded" non-Mezger flat six. Having lived with two highly reliable non-Mezger 986 cars for 2-3 years each and now four of the 9A1/9A2 engine cars, I think the risk factors with the earlier cars is overblown. Our first one, a 1999 986 (supposedly the worst of all) was stone reliable between the 40,000-mile marker when we bought it and 100,000 miles, when we sold it. Today, it has 220,000 miles on the original engine—which required a new RMS at 27,000 miles—in the care of my brother. Still sounds great, and pulls beautifully. Then again, the consequences are nasty if you get stung.
Ergo...I'd look for a 2009-on 997.2 or 991.1 if you want an NA flat six that, while not bulletproof (what truly is?), has shown an enviable record of reliability. Of those, a 997.2 GTS with a 6MT and the standard GTS suspension would be my first choice. That was a very special car.
"What I like about the 911 is that it is all things to all people. Race car and Boulevard cruiser. A commuter and grand tourer. A trophy. A toy. A piece of art. It's both flashy and discrete. You can haul kids, haul skis, or haul ***." - me (Hula)
Hula, I really like your tag line. I have checked almost all those boxes with 911s, and look forward to more.
Hula, I really like your tag line. I have checked almost all those boxes with 911s, and look forward to more.
10-21-2018, 11:19 AM
#11
Rennlist Member
Like others said, the engines in the 997.2 (2009-2012.5) and the 991.1 (2012.5-2016) have been very solid. They are actually the same base engine structure with the 991 having more refinements. If you are going with a PDK car, the 991 PDK became notably more refined in its shifting behavior over the 997.2. The interiors and electronics on the 991 are quite a bit more modern that the 997.2 as well. Coming from the cars you've had, you might find the 997-level electronics a bit too dated.
10-21-2018, 02:55 PM
#12
Burning Brakes
"What I like about the 911 is that it is all things to all people. Race car and Boulevard cruiser. A commuter and grand tourer. A trophy. A toy. A piece of art. It's both flashy and discrete. You can haul kids, haul skis, or haul ***." - me (Hula)
Hula, I really like your tag line. I have checked almost all those boxes with 911s, and look forward to more.
Hula, I really like your tag line. I have checked almost all those boxes with 911s, and look forward to more.
10-21-2018, 09:45 PM
#13
the 9A1 engine has a lot in common with current GT3 R 9A1 Engine and Cayman Gt4 is a 9A1.
The 9A1 is used in IMSA Cayman GT4's and a upgraded variant WEC / IMSA RSR
so they 9A1 is the modern mezger...
hope that helps
the 9A1 is bullet proof
video Porsche released
The 9A1 is used in IMSA Cayman GT4's and a upgraded variant WEC / IMSA RSR
so they 9A1 is the modern mezger...
hope that helps
the 9A1 is bullet proof
video Porsche released
10-21-2018, 10:36 PM
#14
the 9A1 engine has a lot in common with current GT3 R 9A1 Engine and Cayman Gt4 is a 9A1.
The 9A1 is used in IMSA Cayman GT4's and a upgraded variant WEC / IMSA RSR
so they 9A1 is the modern mezger...
hope that helps
the 9A1 is bullet proof
video Porsche released
https://www.youtube.com/watch?v=fv53RbvgfGc
The 9A1 is used in IMSA Cayman GT4's and a upgraded variant WEC / IMSA RSR
so they 9A1 is the modern mezger...
hope that helps
the 9A1 is bullet proof
video Porsche released
https://www.youtube.com/watch?v=fv53RbvgfGc
