Maintenance and reliability of rear wheel/axle steering system?
09-05-2020, 04:32 PM
#46
RL Community Team
Rennlist Member
Rennlist Member
with your impressive background (And sorry if this is a bit off topic, but it relates to reliability) .. what are the achilles heel items in cars today (namely the 992) in terms of long term reliability and viability... in other words, can you see a 992 in existence, running mostly as it did at time of delivery in 20 years? with 500K miles? Or are too many parts life limited in such a way as the car is in effect disposable?
I have an EE degree myself from some 25 years ago, but haven't worked in the field ever.. But I know for example in my career field which is working with commercial aircraft, the "Aerospace grade" systems on those planes can last for decades.
I have an EE degree myself from some 25 years ago, but haven't worked in the field ever.. But I know for example in my career field which is working with commercial aircraft, the "Aerospace grade" systems on those planes can last for decades.
Why? Because I'm not sure older generation cars were necessarily more reliable than newer models. Keeping it in the family, lets say an air cooled 911 like the 993 is probably not more reliable than a water cooled "modern" 911 like the 991 (in fact, I would say the 993 is by all account less reliable -- but that's a different thread).
What I think gives the impression that older generation cars are more reliable is that they can be more easily fixed when something does go wrong out-of-warranty. You can easily take a 993 to an Indie shop and have whatever ails the car fixed, and sourcing parts (either OEM or aftermarket) is generally not a problem, nor cost-prohibitive.
With more modern cars, such as a 991 911, the story is a bit different. While the rate of failure (i.e., reliability in the absolute sense) may or may not be different, the real differentiating factor between a 993 and a 991 is that when something does break out-of-warranty, the ability to repair is either very costly or something a pure Indie shop may not be equipped to handle. An example: When a PDK box breaks, Porsche (during the OEM warranty period) simply replaces the entire unit, instead of diagnosing the problem and fixing it. And a PDK box, if I recall correctly, costs something like 20k (if not more). PAG doesn't even make parts for the PDK box to be distributed for dealers or for sale, if I recall correctly. So when that same unit breaks out-of-warranty, you're faced with a 20k bill, and not simply taking it to an Indie and having them source the parts and fixing the unit. This is what makes more modern cars seem less reliable. It's not that the car is more likely to break, it's just that when it breaks it really f*cking breaks.
Blame it on the "disposable" car mentality of the current generation.
Last edited by ipse dixit; 09-05-2020 at 04:38 PM.
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992Sam (09-06-2020)
09-05-2020, 04:46 PM
#47
Rennlist Member
with your impressive background (And sorry if this is a bit off topic, but it relates to reliability) .. what are the achilles heel items in cars today (namely the 992) in terms of long term reliability and viability... in other words, can you see a 992 in existence, running mostly as it did at time of delivery in 20 years? with 500K miles? Or are too many parts life limited in such a way as the car is in effect disposable?
I have an EE degree myself from some 25 years ago, but haven't worked in the field ever.. But I know for example in my career field which is working with commercial aircraft, the "Aerospace grade" systems on those planes can last for decades.
I have an EE degree myself from some 25 years ago, but haven't worked in the field ever.. But I know for example in my career field which is working with commercial aircraft, the "Aerospace grade" systems on those planes can last for decades.
Keep in mind Reliability != Durability. Our cars are generally both very reliable and very durable.
Mechanically, cars are pretty durable unless you are unlucky (bore-scoring, broken clip in the transmission, etc). Most (but not all!) serious manufacturer's defects that will render the car unusable will show up in the warranty period. If you drive very low miles, it's probably a good idea to get an extended warranty, as you might not put enough time on the car in the 4 years of the OEM warranty.
Electronics are much maligned, but they are pretty darned reliable. I don't worry about those. Even microswitches (which were terrible in 80s and 90s cars) are pretty good now. In hot climates like Houston where I am, some plastic gears in things like A/C flapper valves, automatic sunshades, and old-school odometers melt and cause havoc. I don't think the 991.x has many of these failure points (maybe the glue on the standard door cards that falls apart in the heat). Environmentally, I wish all modern cars would quit using "environmentally friendly" soy-based wiring loom covers that attract animals...but that's generally an insurance issue.
I do think the A/C systems in many modern cars are not as durable as they used to be. But Porsches are generally much better than they used to be in the 70's - 90's.
Maintenance is expensive - moreso on Porsches than on most other cars (but its no Ferrari!). Just expect that you will be spending a lot to keep it running well. I will say that Porsche, unlike many car companies, always has, and continues to use top-shelf materials in the construction of their vehicles. They don't (generally) use plastics where they shouldn't be used, and when they make a switch of materials they test them thoroughly. With the exception of the water-pump impeller and seal issues that they continue to have - I can't really think of a part that I see as having systemic failures with on the 997/991. I know many owners with > 150K on their 996/997s and some getting up there on the 991s. I think they are really pretty durable cars.
The biggest issue in my mind is the impedance mismatch between what people want to pay to maintain their Porsches (nothing) and what it actually costs (a lot!). My 993 that I owned for 17 years from 60K miles to 108K miles consumed about $25K (about half its value!) in maintenance over that period (and that was without any top-end rebuild). I expect my 991.2 Carrera T will exceed that over the 20 years I plan to own the car. So I put aside a little investment account for maintenance when I bought the car. If you budget $35-$40K for expected maintenance, you can keep your 991 on the road and operating at top condition for many years and miles.
Hope that helps!
PS - Started my career at McDonnell Douglas on the F18 E/F program. Re:Aerospace grade engineering...Porsche is about as close as a large auto manufacturer comes.
Last edited by 911-TOUR; 09-05-2020 at 04:55 PM.
09-05-2020, 04:56 PM
#48
Rennlist Member
Something to keep in mind on the PDK box. This new gen 8spd is robust. It was built with the capability to handle much higher power & torque levels for future electrification. Though it’s in the early stages, I imagine it will outlast the previous gen.
09-05-2020, 05:08 PM
#49
Rennlist Member
Well, since you asked :-)
Keep in mind Reliability != Durability. Our cars are generally both very reliable and very durable.
Mechanically, cars are pretty durable unless you are unlucky (bore-scoring, broken clip in the transmission, etc). Most (but not all!) serious manufacturer's defects that will render the car unusable will show up in the warranty period. If you drive very low miles, it's probably a good idea to get an extended warranty, as you might not put enough time on the car in the 4 years of the OEM warranty.
Electronics are much maligned, but they are pretty darned reliable. I don't worry about those. Even microswitches (which were terrible in 80s and 90s cars) are pretty good now. In hot climates like Houston where I am, some plastic gears in things like A/C flapper valves, automatic sunshades, and old-school odometers melt and cause havoc. I don't think the 991.x has many of these failure points (maybe the glue on the standard door cards that falls apart in the heat). Environmentally, I wish all modern cars would quit using "environmentally friendly" soy-based wiring loom covers that attract animals...but that's generally an insurance issue.
I do think the A/C systems in many modern cars are not as durable as they used to be. But Porsches are generally much better than they used to be in the 70's - 90's.
Maintenance is expensive - moreso on Porsches than on most other cars (but its no Ferrari!). Just expect that you will be spending a lot to keep it running well. I will say that Porsche, unlike many car companies, always has, and continues to use top-shelf materials in the construction of their vehicles. They don't (generally) use plastics where they shouldn't be used, and when they make a switch of materials they test them thoroughly. With the exception of the water-pump impeller and seal issues that they continue to have - I can't really think of a part that I see as having systemic failures with on the 997/991. I know many owners with > 150K on their 996/997s and some getting up there on the 991s. I think they are really pretty durable cars.
The biggest issue in my mind is the impedance mismatch between what people want to pay to maintain their Porsches (nothing) and what it actually costs (a lot!). My 993 that I owned for 17 years from 60K miles to 108K miles consumed about $25K (about half its value!) in maintenance over that period (and that was without any top-end rebuild). I expect my 991.2 Carrera T will exceed that over the 20 years I plan to own the car. So I put aside a little investment account for maintenance when I bought the car. If you budget $35-$40K for expected maintenance, you can keep your 991 on the road and operating at top condition for many years and miles.
Hope that helps!
PS - Started my career at McDonnell Douglas on the F18 E/F program. Re:Aerospace grade engineering...Porsche is about as close as a large auto manufacturer comes.
Keep in mind Reliability != Durability. Our cars are generally both very reliable and very durable.
Mechanically, cars are pretty durable unless you are unlucky (bore-scoring, broken clip in the transmission, etc). Most (but not all!) serious manufacturer's defects that will render the car unusable will show up in the warranty period. If you drive very low miles, it's probably a good idea to get an extended warranty, as you might not put enough time on the car in the 4 years of the OEM warranty.
Electronics are much maligned, but they are pretty darned reliable. I don't worry about those. Even microswitches (which were terrible in 80s and 90s cars) are pretty good now. In hot climates like Houston where I am, some plastic gears in things like A/C flapper valves, automatic sunshades, and old-school odometers melt and cause havoc. I don't think the 991.x has many of these failure points (maybe the glue on the standard door cards that falls apart in the heat). Environmentally, I wish all modern cars would quit using "environmentally friendly" soy-based wiring loom covers that attract animals...but that's generally an insurance issue.
I do think the A/C systems in many modern cars are not as durable as they used to be. But Porsches are generally much better than they used to be in the 70's - 90's.
Maintenance is expensive - moreso on Porsches than on most other cars (but its no Ferrari!). Just expect that you will be spending a lot to keep it running well. I will say that Porsche, unlike many car companies, always has, and continues to use top-shelf materials in the construction of their vehicles. They don't (generally) use plastics where they shouldn't be used, and when they make a switch of materials they test them thoroughly. With the exception of the water-pump impeller and seal issues that they continue to have - I can't really think of a part that I see as having systemic failures with on the 997/991. I know many owners with > 150K on their 996/997s and some getting up there on the 991s. I think they are really pretty durable cars.
The biggest issue in my mind is the impedance mismatch between what people want to pay to maintain their Porsches (nothing) and what it actually costs (a lot!). My 993 that I owned for 17 years from 60K miles to 108K miles consumed about $25K (about half its value!) in maintenance over that period (and that was without any top-end rebuild). I expect my 991.2 Carrera T will exceed that over the 20 years I plan to own the car. So I put aside a little investment account for maintenance when I bought the car. If you budget $35-$40K for expected maintenance, you can keep your 991 on the road and operating at top condition for many years and miles.
Hope that helps!
PS - Started my career at McDonnell Douglas on the F18 E/F program. Re:Aerospace grade engineering...Porsche is about as close as a large auto manufacturer comes.
The problem is, that the modern features and functions that we like for comfort and performance, are tech driven - so while I worry more about the electronics over time failing, can't live without them (for a daily driver anyway).
Last edited by Richard_Wallace; 09-05-2020 at 05:09 PM.
09-05-2020, 05:20 PM
#50
Banned
Thread Starter
09-05-2020, 05:24 PM
#51
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Thread Starter
09-05-2020, 05:27 PM
#52
Banned
Thread Starter
My comment just to provide context on the number of RAS Porsches out there when assessing problems posted on forums (e.g., what smiles posted) and in response to your comment that Porsche has made only hundreds of RAS cars. We know from the data that it's at least tens of thousands. Yes, your specific dealer may not have sold very many.
I agree with the recommendation to look at the actuator part cost. But if you're focused more on time rather than $$$, it doesn't help you much.
I agree with the recommendation to look at the actuator part cost. But if you're focused more on time rather than $$$, it doesn't help you much.
..
Last edited by CodyBigdog; 09-05-2020 at 05:31 PM.
09-05-2020, 05:29 PM
#53
Banned
Thread Starter
My comment just to provide context on the number of RAS Porsches out there when assessing problems posted on forums (e.g., what smiles posted) and in response to your comment that Porsche has made only hundreds of RAS cars. We know from the data that it's at least tens of thousands. Yes, your specific dealer may not have sold very many.
I agree with the recommendation to look at the actuator part cost. But if you're focused more on time rather than $$$, it doesn't help you much.
I agree with the recommendation to look at the actuator part cost. But if you're focused more on time rather than $$$, it doesn't help you much.
“A least 10’s of thousands”. Great, can I see your data/link? Thanks in advance.
09-05-2020, 05:40 PM
#54
Banned
Thread Starter
RE: “If you budget $35-$40K for expected maintenance, you can keep your 991 on the road and operating at top condition for many years and miles.”
I hope that isn;’t annually? Care to normalize maintenance cost by miles or years of operation? Thx
I hope that isn;’t annually? Care to normalize maintenance cost by miles or years of operation? Thx
09-05-2020, 07:41 PM
#55
Burning Brakes
The good news here is that Porsche, unlike BMW actually supports the older cars with parts and service. This is probably the biggest reason, I stopped by buying BMWs. I keep my cars a long time and want to know that no matter what, my car company will continue to support the parts in my car. Porsche even goes so so far as to redesign old parts making them better. It may cost but you will always be able to repair your car. Not true for BMW or most other car manufacturers .
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Tompoodie (10-22-2020)
09-05-2020, 07:58 PM
#56
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Thread Starter
The good news here is that Porsche, unlike BMW actually supports the older cars with parts and service. This is probably the biggest reason, I stopped by buying BMWs. I keep my cars a long time and want to know that no matter what, my car company will continue to support the parts in my car. Porsche even goes so so far as to redesign old parts making them better. It may cost but you will always be able to repair your car. Not true for BMW or most other car manufacturers .
How old? My son bought a used 1993 325iS in college and kept it for another 10 years after college in Chicago. He had no problem getting parts/serviced for his 15+ yo BMW..
Last edited by CodyBigdog; 09-05-2020 at 08:22 PM.
09-05-2020, 08:12 PM
#57
Rennlist Member
Hope that helps!
Last edited by 911-TOUR; 09-05-2020 at 08:13 PM.
09-05-2020, 08:20 PM
#58
Banned
Thread Starter
I think mileage is more meaningful, than years of ownership. Most Porsche owners I know, barely crack 5K miles per year...and sit in the garage most of their life. Then, of course, it also depends on how the car is driven - weekend joy rides don’t compare to weekend track time.
09-05-2020, 08:51 PM
#59
Burning Brakes
1988 to 1991 E30. Also E36 cars are starting to have parts go NLA. Check out realoem. Porsche supports 911s going back to the 1960s. They will also rebuild any Porsche including 356. Ask you BMW dealer if they will do the same.
Last edited by inastrangeland; 09-05-2020 at 08:53 PM.
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Cartod (01-17-2023)
09-05-2020, 08:59 PM
#60
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Thread Starter
After the warrenty runs out, I take my BMW to any number of independent garages within 10 miles of my house. Cheaper and often, better service. There are a LOT of BMW’s out on the road - way more than Porsche - so finding places that will repair my (or son’s) BMW has never been a problem. Maybe not your experience, but it it’s been mine.
Last edited by CodyBigdog; 09-05-2020 at 09:01 PM.