Doing clutch, not touching IMS
11-19-2018, 01:39 AM
#31
Rennlist Member
-Drives it hard is more of an argument to replace it.
-Yes than can fail for many reasons but this is one so why risk it
-It is expensive IF YOU ARE NOT ALREADY DOING THE CLUTCH, he mechanic will literally be looking at the IMS. So you wouldn't endure the added cost of basically the part only to possibly avoid cooking a 12k engine later? This makes ZERO sense to me.
-Yes than can fail for many reasons but this is one so why risk it
-It is expensive IF YOU ARE NOT ALREADY DOING THE CLUTCH, he mechanic will literally be looking at the IMS. So you wouldn't endure the added cost of basically the part only to possibly avoid cooking a 12k engine later? This makes ZERO sense to me.
Another valid point of view is why put any money into them and just roll the dice on your luck. The argument here is why spend a lot of money on an unreliable engine that still doesn't make it much more reliable. Valid argument.
You think it's a good idea to spend ~$2k on an already unreliable engine. I can see where you're coming from. However, I can also easily find a large number of people who thinks it makes no sense to even buy a car that is so unreliable. Who is right? Both? I think so.
Lots of points of views when it comes to these cars, all having some degree of validity, too.
As for daily driving/running these cars hard, evidence points towards these examples as being affected least by failed IMSBs. Cars that sit parked and driven on rare occassions tend to fail more often. Plus, based on my research, the bearing experiences the most stress when the engine is idling, not while revving.
Again, there's no right answer when it comes to preventative maintenance on these engines. Anything short of a full rebuild is a gamble.
The OP impresses me because he's actually being objective in his decision.
11-19-2018, 01:46 AM
#32
Rennlist Member
But what if his engine fails for another reason other than the IMSB before he sells? Still no peace of mind. No full refund!
11-19-2018, 05:53 AM
#33
Ectually, the lawsuit covers all cars from 1/1/2001 though the end of 2005. I don't believe the settlement discusses the type of bearing installed. obviously, this car being a model year 2001 was within the period defined in the lawsuit. Not that there's anything anyone can do about it now, as the last of the remediation is long behind us.
LN estimates a 10% premature failure rate. In terms of modern mechanical design targets, this is out of spec by about a factor of 10,000. (sixth sigma = 0.00034, but who's counting decimals anyway). So, in effect, this is Russian roulette - but with a 10 barrel revolver(if there is such an animal).
LN estimates a 10% premature failure rate. In terms of modern mechanical design targets, this is out of spec by about a factor of 10,000. (sixth sigma = 0.00034, but who's counting decimals anyway). So, in effect, this is Russian roulette - but with a 10 barrel revolver(if there is such an animal).
The 10% estimate is for single-rows, you know that, so I'm a bit surprised you're framing it as if both IMSB's have that rate. It's specifically mentioned that dual-row IMSB has <1% failure rate.
11-19-2018, 08:27 AM
#34
Whether or not it needs to be replaced or is a good idea, one thing that changing it has a HUGE impact on is resale. IMS is a known issue with these cars and buyers know it. The person I bought my C4 from had it for sale for 6 months at a fair price and a lot of people looked at it. He said every person asked about the IMS and numerous people walked away specifically because it had not been changed.
I’d change it for that reason alone. You’ll get far more than the cost of the change out of the car at resale time.
I’d change it for that reason alone. You’ll get far more than the cost of the change out of the car at resale time.
11-19-2018, 08:52 AM
#35
It doesn't make sense to you because you're looking at it from only one point of view. These engines are unique in that they are essentially ticking time bombs. If the IMSB was the only issue with these engines, I would agree with you 100%. That's clearly not the case though. That's why there are several points of view.
Another valid point of view is why put any money into them and just roll the dice on your luck. The argument here is why spend a lot of money on an unreliable engine that still doesn't make it much more reliable. Valid argument.
You think it's a good idea to spend ~$2k on an already unreliable engine. I can see where you're coming from. However, I can also easily find a large number of people who thinks it makes no sense to even buy a car that is so unreliable. Who is right? Both? I think so.
Lots of points of views when it comes to these cars, all having some degree of validity, too.
As for daily driving/running these cars hard, evidence points towards these examples as being affected least by failed IMSBs. Cars that sit parked and driven on rare occassions tend to fail more often. Plus, based on my research, the bearing experiences the most stress when the engine is idling, not while revving.
Again, there's no right answer when it comes to preventative maintenance on these engines. Anything short of a full rebuild is a gamble.
The OP impresses me because he's actually being objective in his decision.
Another valid point of view is why put any money into them and just roll the dice on your luck. The argument here is why spend a lot of money on an unreliable engine that still doesn't make it much more reliable. Valid argument.
You think it's a good idea to spend ~$2k on an already unreliable engine. I can see where you're coming from. However, I can also easily find a large number of people who thinks it makes no sense to even buy a car that is so unreliable. Who is right? Both? I think so.
Lots of points of views when it comes to these cars, all having some degree of validity, too.
As for daily driving/running these cars hard, evidence points towards these examples as being affected least by failed IMSBs. Cars that sit parked and driven on rare occassions tend to fail more often. Plus, based on my research, the bearing experiences the most stress when the engine is idling, not while revving.
Again, there's no right answer when it comes to preventative maintenance on these engines. Anything short of a full rebuild is a gamble.
The OP impresses me because he's actually being objective in his decision.
11-19-2018, 09:36 AM
#36
Burning Brakes
I would highly agree with this statement. When i called the Porsche dealer to inquire about purchasing my car that was the first thing the salesman said "It has not had the IMS replaced.". I even laughed and asked if he was actually trying to sell the car. He said they have had people all over the nation call and they hang up as soon as the hear about it. I just negotiated replacing the IMS, Clutch and RMS for an additional 2k over the asking price. They had no issue with it and neither did I.
Last edited by Mbren1979; 11-19-2018 at 11:43 AM.
11-19-2018, 11:39 AM
#37
Rennlist Member
^^ Yep.
I would agree with not changing a dual-row, or the later, larger single-row, but the small single-row one that was based on the lawsuit, now THAT one, I would change almost regardless of clutch and having the engine dropped. Now that the engine is dropped and apart, I would almost certainly change it out.
You could argue that the OP is technically making the “right” decision, technically, based on risk/reward, since there’s a 9 out of 10 chance the bearing won’t fail, and if you apply poker math/strategy to the equation. However, the argument falls down when you look at the economically correct decision. For example, if one were to buy 100 cars and have 10 bearings that fail, at $20k apice for rebuild, we have $200k in repairs, versus $100k of cost to replace the IMS on all 100 cars. So, economically, it is an incorrect choice to not replace the IMS if it’s $1000. Break even is $2,000, but that seems too steep.
I would agree with not changing a dual-row, or the later, larger single-row, but the small single-row one that was based on the lawsuit, now THAT one, I would change almost regardless of clutch and having the engine dropped. Now that the engine is dropped and apart, I would almost certainly change it out.
You could argue that the OP is technically making the “right” decision, technically, based on risk/reward, since there’s a 9 out of 10 chance the bearing won’t fail, and if you apply poker math/strategy to the equation. However, the argument falls down when you look at the economically correct decision. For example, if one were to buy 100 cars and have 10 bearings that fail, at $20k apice for rebuild, we have $200k in repairs, versus $100k of cost to replace the IMS on all 100 cars. So, economically, it is an incorrect choice to not replace the IMS if it’s $1000. Break even is $2,000, but that seems too steep.
11-19-2018, 03:05 PM
#38
Shameful Thread Killer
Rennlist Member
Rennlist Member
I feel like you're looking for lightning where there isn't any, since you know damn well why <2001 isn't covered in the lawsuit. It's precisely because those have dual rows. 2001 being a changeover year, where some are and some aren't single-row and it's impossible to just tell by build date, they decided to cover the entire year but even then differentiate between serial numbers.
The 10% estimate is for single-rows, you know that, so I'm a bit surprised you're framing it as if both IMSB's have that rate. It's specifically mentioned that dual-row IMSB has <1% failure rate.
The 10% estimate is for single-rows, you know that, so I'm a bit surprised you're framing it as if both IMSB's have that rate. It's specifically mentioned that dual-row IMSB has <1% failure rate.
If one wants to live with a ~1% failure rate, where the cost of failure is $20,000, and the cost of remediation is $600-$1000, it's ok with me. I'm a numbers guy. I had a 99 with a perfect dual row bearing. But - numbers don't lie. 1% failure rate is way, way, way higher than I was willing to risk, particularly when I'm standing under the car, STARING at the IMS cover with the trans sitting on the floor.
Have a nice day.
11-19-2018, 03:43 PM
#40
Three Wheelin'
Could write a weekly newsletter based on everyone's IMSB opinions.
Do the clutch and don't change the IMS, could have an issue down the road, might not and all will be fine.
Do the clutch and change the IMS, one less potential worry and is now a buyers incentive if you decide to sell the car.
Either way, it's how much the cost of the risk is worth to you and what you plan for the future. Have the extra money laying around and want extra peace of mind while accessible since doing the clutch? Cool do it. Not worried about it and want to drive the car as is? Cool do it.
The world is your oyster.
Do the clutch and don't change the IMS, could have an issue down the road, might not and all will be fine.
Do the clutch and change the IMS, one less potential worry and is now a buyers incentive if you decide to sell the car.
Either way, it's how much the cost of the risk is worth to you and what you plan for the future. Have the extra money laying around and want extra peace of mind while accessible since doing the clutch? Cool do it. Not worried about it and want to drive the car as is? Cool do it.
The world is your oyster.
11-19-2018, 03:49 PM
#42
Wow, pretty emotional topic. My car is at a shop a stone's throw away from the thread starter. I'm getting the IMS Solution ++++++ on a 45000 mile car. Why? I am very risk averse and am trying to mitigate blowing a motor from a bad bearing design.
I wish I was not as risk averse ad I am. In some ways I applaud the thread starter for his approach.
Me, I was influenced by all the IMS failure lore and am paying $$$$$ dearly for it. Only time will tell who made the best decision.
I wish I was not as risk averse ad I am. In some ways I applaud the thread starter for his approach.
Me, I was influenced by all the IMS failure lore and am paying $$$$$ dearly for it. Only time will tell who made the best decision.
11-19-2018, 05:07 PM
#43
Drifting
One thing to bear in mind is that the 1% (dual-row) / 8% (single-row) statistic from the lawsuit is a data "snapshot" from a long time ago. All 996's are a lot older and they all have a lot more miles than they did back then, so the current failure percentage rate (for an original bearing at least) is probably quite a bit higher than it was back then. If the IMS has been changed at some point, then maybe 1%/8% is still roughly accurate, but if a car is still on the original bearing, the failure rate is probably quite a bit higher.
11-19-2018, 05:32 PM
#44
Well here are my 5 cents.
I am kind in the same boat than the thread starter. I have an invoice of almost 3000$ onmy car at San Diego Porsche, where they changed the clutch, the RMS (with the new good 997 reference), IMS Flange/Housing, seal rings, cylinder hed seals etc. However, it seems that they didnt change the bearing itself (at least not with a porsche part).
Why?... well it would take to the end of the days kind of discussion to define what is better, if an original bearing mounted from the factory with the engine that has no signs of failure, or an aftermarket one...
I have to say though, that since I live here in US, I have realized that the view about the IMS "problem" is quite different from the one that we have in Europe. Although in both sides of the Atlantic the IMS is a point of concern with engines, I think that here we freak out a little bit more. Short story... in EU, if a 996 has been well cared (frequent oil changes, quality oil, driving respecting warming up times, etc)... and has not failed until today, you even consider them like quite reliable cars, and the proof is that you can see 996 with high millage without any service on the IMS.
I am kind in the same boat than the thread starter. I have an invoice of almost 3000$ onmy car at San Diego Porsche, where they changed the clutch, the RMS (with the new good 997 reference), IMS Flange/Housing, seal rings, cylinder hed seals etc. However, it seems that they didnt change the bearing itself (at least not with a porsche part).
Why?... well it would take to the end of the days kind of discussion to define what is better, if an original bearing mounted from the factory with the engine that has no signs of failure, or an aftermarket one...
I have to say though, that since I live here in US, I have realized that the view about the IMS "problem" is quite different from the one that we have in Europe. Although in both sides of the Atlantic the IMS is a point of concern with engines, I think that here we freak out a little bit more. Short story... in EU, if a 996 has been well cared (frequent oil changes, quality oil, driving respecting warming up times, etc)... and has not failed until today, you even consider them like quite reliable cars, and the proof is that you can see 996 with high millage without any service on the IMS.
11-19-2018, 06:02 PM
#45
Rennlist Member
Engine blows, sell as a roller and look for another cheap 996...Wash and repeat!