The IMS discussion thread (Read this first!)
07-13-2015, 11:23 AM
#91
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According to the Eisen IMS class action lawsuit, data reveal that the rate of IMS failure in MY98-99 dual row bearing is 1%.
In the article about the 996 “Exploding myths” in Total 911 we can read:
“First, it’s important to point out that it is the early 3.4-litre engines, made from 1998 to 2000, that are most susceptible to major failure. (…)”.
There seems to be misinformation on the IMS topic.
In the article about the 996 “Exploding myths” in Total 911 we can read:
“First, it’s important to point out that it is the early 3.4-litre engines, made from 1998 to 2000, that are most susceptible to major failure. (…)”.
There seems to be misinformation on the IMS topic.
07-13-2015, 04:34 PM
#93
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07-18-2015, 02:57 PM
#94
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Happiness is........
Getting your 2003 C4S back on the road after being garaged for 1.5 years. Thought I blew the engine but when I trailered it 120 miles to Newport Beach, I found the best P-car mech I've ever met. Singh Kaku (European Car Specialists) replaced the Air-Oil separator and put in a new coolant tank (I was blowing white smoke when I garaged it). Since it had been sitting, the RMS was leaking. Singh convinced me to do the IMS upgrade. It looked expensive since he recommended the LN Engineering ceramic one $800. Since he saved me a boat load of money on the engine (I had saved for a new one, this one had 187K miles on it), I made the decision to do everything I could. New motor & transmission mounts, new clutch, RMS and upgraded bearing, several cosmetic things and I picked it up last week.
Happiness is having a P-car that drives like it is brand new, tight as ever, quick as ever. Happiness is also knowing that the IMS bearing will last - Mine had 187K on it but you could tell it was a little loose. Happiness is having a P-car mech that you can absolutely trust, will do an expert quality job and be reasonable about it. Color me Happy.
- Fast Frank 2003 C4S
Happiness is having a P-car that drives like it is brand new, tight as ever, quick as ever. Happiness is also knowing that the IMS bearing will last - Mine had 187K on it but you could tell it was a little loose. Happiness is having a P-car mech that you can absolutely trust, will do an expert quality job and be reasonable about it. Color me Happy.
- Fast Frank 2003 C4S
07-19-2015, 08:18 PM
#95
Getting your 2003 C4S back on the road after being garaged for 1.5 years. Thought I blew the engine but when I trailered it 120 miles to Newport Beach, I found the best P-car mech I've ever met. Singh Kaku (European Car Specialists) replaced the Air-Oil separator and put in a new coolant tank (I was blowing white smoke when I garaged it). Since it had been sitting, the RMS was leaking. Singh convinced me to do the IMS upgrade. It looked expensive since he recommended the LN Engineering ceramic one $800. Since he saved me a boat load of money on the engine (I had saved for a new one, this one had 187K miles on it), I made the decision to do everything I could. New motor & transmission mounts, new clutch, RMS and upgraded bearing, several cosmetic things and I picked it up last week.
Happiness is having a P-car that drives like it is brand new, tight as ever, quick as ever. Happiness is also knowing that the IMS bearing will last - Mine had 187K on it but you could tell it was a little loose. Happiness is having a P-car mech that you can absolutely trust, will do an expert quality job and be reasonable about it. Color me Happy.
- Fast Frank 2003 C4S
Happiness is having a P-car that drives like it is brand new, tight as ever, quick as ever. Happiness is also knowing that the IMS bearing will last - Mine had 187K on it but you could tell it was a little loose. Happiness is having a P-car mech that you can absolutely trust, will do an expert quality job and be reasonable about it. Color me Happy.
- Fast Frank 2003 C4S
07-21-2015, 06:51 PM
#96
Burning Brakes
So about two weeks ago I bought a 2001 C4 with 32,XXX miles and the DREADED SINGLE ROW IMSB OF DEATH!
Drove it for a couple of days, went on vacation, checked the tire pressure and took that bitch out to my first autocross and pushed it as hard as I could.
Dropped it off Monday for a FULL service and decided to go with the LNE retrofit dual row bearing upgrade while I was at it.
The original bearing looks brand new. Feels brand new. My mechanic told me that out of all the IMSB he has replaced he has found a grand total of ZERO that were bad. Dual row, single row, MT, Tip, garage queen, race car...none of the original bearings were bad.
Still, it feels good knowing I have that LNE in there and wont have to worry about it again as long as I own the vehicle.
FWIW
Drove it for a couple of days, went on vacation, checked the tire pressure and took that bitch out to my first autocross and pushed it as hard as I could.
Dropped it off Monday for a FULL service and decided to go with the LNE retrofit dual row bearing upgrade while I was at it.
The original bearing looks brand new. Feels brand new. My mechanic told me that out of all the IMSB he has replaced he has found a grand total of ZERO that were bad. Dual row, single row, MT, Tip, garage queen, race car...none of the original bearings were bad.
Still, it feels good knowing I have that LNE in there and wont have to worry about it again as long as I own the vehicle.
FWIW
07-21-2015, 10:05 PM
#97
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So about two weeks ago I bought a 2001 C4 with 32,XXX miles and the DREADED SINGLE ROW IMSB OF DEATH!
Drove it for a couple of days, went on vacation, checked the tire pressure and took that bitch out to my first autocross and pushed it as hard as I could.
Dropped it off Monday for a FULL service and decided to go with the LNE retrofit dual row bearing upgrade while I was at it.
The original bearing looks brand new. Feels brand new. My mechanic told me that out of all the IMSB he has replaced he has found a grand total of ZERO that were bad. Dual row, single row, MT, Tip, garage queen, race car...none of the original bearings were bad.
Still, it feels good knowing I have that LNE in there and wont have to worry about it again as long as I own the vehicle.
FWIW
Drove it for a couple of days, went on vacation, checked the tire pressure and took that bitch out to my first autocross and pushed it as hard as I could.
Dropped it off Monday for a FULL service and decided to go with the LNE retrofit dual row bearing upgrade while I was at it.
The original bearing looks brand new. Feels brand new. My mechanic told me that out of all the IMSB he has replaced he has found a grand total of ZERO that were bad. Dual row, single row, MT, Tip, garage queen, race car...none of the original bearings were bad.
Still, it feels good knowing I have that LNE in there and wont have to worry about it again as long as I own the vehicle.
FWIW
07-22-2015, 03:56 AM
#98
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Which To Choose
Hi, first time post here. I thought I post here since it has some IMS related question.
I am in the prospect of buying a 996 c2 convertible, have 2 options:
1. 1999 with 62k miles for $20k
2. 2000 with 130k miles for $15k
both are 1 owner car with good condition, service regularly, have service records but neither has the IMS bearing replaced.
Questions:
1. Are the price fair (it is per KBB), or should I negotiate for less for the IMS replacement
2. Which one should I get if I want to make it as my daily driver 60 miles commute round trip. I am planning to keep it as long as I can.
Obviously I will also do PPI prior committing just to be on the safe side.
Thanks!
I am in the prospect of buying a 996 c2 convertible, have 2 options:
1. 1999 with 62k miles for $20k
2. 2000 with 130k miles for $15k
both are 1 owner car with good condition, service regularly, have service records but neither has the IMS bearing replaced.
Questions:
1. Are the price fair (it is per KBB), or should I negotiate for less for the IMS replacement
2. Which one should I get if I want to make it as my daily driver 60 miles commute round trip. I am planning to keep it as long as I can.
Obviously I will also do PPI prior committing just to be on the safe side.
Thanks!
Last edited by RoadWarrior68; 07-22-2015 at 04:40 AM.
08-26-2015, 07:02 PM
#100
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How much did you spend to replace your 996's IMS?
Just lost my 98 Boxster to a bad head gasket and I'm looking to replace it with a 996. I'm most interested in the MKII engines and a 2002-2004 is in my price range. Conventional wisdom dictates I buy as new a model has possible. However, I've been told that in mid-2003 there was a change made that makes the late-2003 and all 2004s more difficult to work on than the 2002s and early 2003s. Any truth to this?
How much should I expect to spend on an IMS retrofit for a 2002-2004 996?
How much should I expect to spend on an IMS retrofit for a 2002-2004 996?
09-17-2015, 10:26 AM
#102
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my 98 996 c2 tip with 60,000 is running fine, and i regularly take it to 6500rpm,
i read all the magazines and tend to find that Total 911 always seems to mention the IMS as if was very high chance of failure and not like the smaller % found in the poll.
If you look at the later designed Audi A5 v8, its timing chain has a similar "catastrophic" problem and the BMW 1,3 and 5 Series diesel timing chain snap, is also a catastrophic problem......
I'm going to enjoy the car till something happens, good luck guys.
i read all the magazines and tend to find that Total 911 always seems to mention the IMS as if was very high chance of failure and not like the smaller % found in the poll.
If you look at the later designed Audi A5 v8, its timing chain has a similar "catastrophic" problem and the BMW 1,3 and 5 Series diesel timing chain snap, is also a catastrophic problem......
I'm going to enjoy the car till something happens, good luck guys.
09-20-2015, 04:01 AM
#103
Alternative Theory
My 2pennyworth.
The failure of the IMS may be more to do with poor tolerance and variance due to lack of quality control at production of the parts. The failures in some cases may be caused initially by very small movement of the bearing housing when under pressure leading to increased stress and wear on the bearings themselves.
This then eventually causes the increase in freeplay that then goes on to destroy first the seal from the centre (leak of grease) then allows further accelerated deteriortion of the bearing and the bearing race proper.
It is not likely to be simply failure of the seals as bearings can survive with very small amounts of lubrication. The seals were supposed to be designed to withstand the higher running temps of the engine. There are reports of low mileage IMS failures and if the seal theory were true then they were pretty crap to go so soon and why would 92% be fine and 8% not be - there must be other factors involved.
That may be why there are differing mileages for IMS bearing collapse. It is because they are starting at different degrees of tolerance, some will be fine some a mircon out of some much worse etc.
That is also why Porsche were at first wipping away defective engines and replacing them because they did not know what was going on at first.
What 'premium' company would admit to poor quality components?
That could also explain why they remained silent for so long. They did not know what the longer term outcome would look like in numbers of failures. It would not have taken long for someone to extrapolate likely failure rates and the then ever decreasing numbers of failures as time went on.
That theory would also explain why not all IMS bearings have failed. Those that were within acceptable tolerance in regards to quality and 'fit' have stood the test of endurance as they were expected to.
We have all read the stories of bearings being 'upgraded' only to be told it was 'like new and seals intact'.
That may also explain why the instances of failure are tailing off, if you beleive the latest polls. The cars have been out of production for 10 years now but still, using a theoretical bell shaped graph it would show a peak of failure 'those that were always going to fail' and then reduce as those that were ok remain and others are replaced as precautions.
To cut the boring rantings of a madmans theory short. There are a number of factors at play. Quality of the parts. Maybe how you drive the car as low revs high gear combinations would increase the stress on the relevant parts of the engine, and if they were not up to par in the first place, increase the wear/damage.
On the upside. IF any of this crazy theorisation were true then the higher numbers of failures that have been seen in the past (some reports as high as 8%) will not be repeated in the future. Their are no guarrantees in life, other than death and taxes, but those cars that remain are less likely to fail because they were ok in the first place.
A caveat to that would be very late models that have very very low mileages whose less than perfect IMS has not had enough run time yet to fail.
A double caveat is that Porsche may at some point between 2001 and 2005 realised the issue, one would hope they have some smart engineers working for them, and changed production or supplier. That may explain the other theory that there were higher instances of failure in 2001 and 2002 cars - again all theory.
If I had the inclination it would be interesting to excel spreadsheet the model, production year and mileage for each IMS failure to see if there were really any peaks.
I do not work for Porsche but if I did I would be sneaking into the secrets room and pulling the file marked 'Intermediate Shaft Failure - The Truth!!'.
Will I get mine done - yes probably when the clutch needs replacing but not before.
I have never needed to be a 100% person to be able to sleep at night. The replacement would need to be a 'fit and forget' I would not be fitting one of the LN - now to be swapped again at 40K units.
keep it well serviced, drive it and enjoy it - that why you bought it.
Regards
GW
The failure of the IMS may be more to do with poor tolerance and variance due to lack of quality control at production of the parts. The failures in some cases may be caused initially by very small movement of the bearing housing when under pressure leading to increased stress and wear on the bearings themselves.
This then eventually causes the increase in freeplay that then goes on to destroy first the seal from the centre (leak of grease) then allows further accelerated deteriortion of the bearing and the bearing race proper.
It is not likely to be simply failure of the seals as bearings can survive with very small amounts of lubrication. The seals were supposed to be designed to withstand the higher running temps of the engine. There are reports of low mileage IMS failures and if the seal theory were true then they were pretty crap to go so soon and why would 92% be fine and 8% not be - there must be other factors involved.
That may be why there are differing mileages for IMS bearing collapse. It is because they are starting at different degrees of tolerance, some will be fine some a mircon out of some much worse etc.
That is also why Porsche were at first wipping away defective engines and replacing them because they did not know what was going on at first.
What 'premium' company would admit to poor quality components?
That could also explain why they remained silent for so long. They did not know what the longer term outcome would look like in numbers of failures. It would not have taken long for someone to extrapolate likely failure rates and the then ever decreasing numbers of failures as time went on.
That theory would also explain why not all IMS bearings have failed. Those that were within acceptable tolerance in regards to quality and 'fit' have stood the test of endurance as they were expected to.
We have all read the stories of bearings being 'upgraded' only to be told it was 'like new and seals intact'.
That may also explain why the instances of failure are tailing off, if you beleive the latest polls. The cars have been out of production for 10 years now but still, using a theoretical bell shaped graph it would show a peak of failure 'those that were always going to fail' and then reduce as those that were ok remain and others are replaced as precautions.
To cut the boring rantings of a madmans theory short. There are a number of factors at play. Quality of the parts. Maybe how you drive the car as low revs high gear combinations would increase the stress on the relevant parts of the engine, and if they were not up to par in the first place, increase the wear/damage.
On the upside. IF any of this crazy theorisation were true then the higher numbers of failures that have been seen in the past (some reports as high as 8%) will not be repeated in the future. Their are no guarrantees in life, other than death and taxes, but those cars that remain are less likely to fail because they were ok in the first place.
A caveat to that would be very late models that have very very low mileages whose less than perfect IMS has not had enough run time yet to fail.
A double caveat is that Porsche may at some point between 2001 and 2005 realised the issue, one would hope they have some smart engineers working for them, and changed production or supplier. That may explain the other theory that there were higher instances of failure in 2001 and 2002 cars - again all theory.
If I had the inclination it would be interesting to excel spreadsheet the model, production year and mileage for each IMS failure to see if there were really any peaks.
I do not work for Porsche but if I did I would be sneaking into the secrets room and pulling the file marked 'Intermediate Shaft Failure - The Truth!!'.
Will I get mine done - yes probably when the clutch needs replacing but not before.
I have never needed to be a 100% person to be able to sleep at night. The replacement would need to be a 'fit and forget' I would not be fitting one of the LN - now to be swapped again at 40K units.
keep it well serviced, drive it and enjoy it - that why you bought it.
Regards
GW
The following users liked this post:
Mikael Jerzy (12-21-2023)
09-20-2015, 09:44 AM
#104
Former Vendor
My 2pennyworth.
The failure of the IMS may be more to do with poor tolerance and variance due to lack of quality control at production of the parts. The failures in some cases may be caused initially by very small movement of the bearing housing when under pressure leading to increased stress and wear on the bearings themselves.
This then eventually causes the increase in freeplay that then goes on to destroy first the seal from the centre (leak of grease) then allows further accelerated deteriortion of the bearing and the bearing race proper.
It is not likely to be simply failure of the seals as bearings can survive with very small amounts of lubrication. The seals were supposed to be designed to withstand the higher running temps of the engine. There are reports of low mileage IMS failures and if the seal theory were true then they were pretty crap to go so soon and why would 92% be fine and 8% not be - there must be other factors involved.
That may be why there are differing mileages for IMS bearing collapse. It is because they are starting at different degrees of tolerance, some will be fine some a mircon out of some much worse etc.
That is also why Porsche were at first wipping away defective engines and replacing them because they did not know what was going on at first.
What 'premium' company would admit to poor quality components?
That could also explain why they remained silent for so long. They did not know what the longer term outcome would look like in numbers of failures. It would not have taken long for someone to extrapolate likely failure rates and the then ever decreasing numbers of failures as time went on.
That theory would also explain why not all IMS bearings have failed. Those that were within acceptable tolerance in regards to quality and 'fit' have stood the test of endurance as they were expected to.
We have all read the stories of bearings being 'upgraded' only to be told it was 'like new and seals intact'.
That may also explain why the instances of failure are tailing off, if you beleive the latest polls. The cars have been out of production for 10 years now but still, using a theoretical bell shaped graph it would show a peak of failure 'those that were always going to fail' and then reduce as those that were ok remain and others are replaced as precautions.
To cut the boring rantings of a madmans theory short. There are a number of factors at play. Quality of the parts. Maybe how you drive the car as low revs high gear combinations would increase the stress on the relevant parts of the engine, and if they were not up to par in the first place, increase the wear/damage.
On the upside. IF any of this crazy theorisation were true then the higher numbers of failures that have been seen in the past (some reports as high as 8%) will not be repeated in the future. Their are no guarrantees in life, other than death and taxes, but those cars that remain are less likely to fail because they were ok in the first place.
A caveat to that would be very late models that have very very low mileages whose less than perfect IMS has not had enough run time yet to fail.
A double caveat is that Porsche may at some point between 2001 and 2005 realised the issue, one would hope they have some smart engineers working for them, and changed production or supplier. That may explain the other theory that there were higher instances of failure in 2001 and 2002 cars - again all theory.
If I had the inclination it would be interesting to excel spreadsheet the model, production year and mileage for each IMS failure to see if there were really any peaks.
I do not work for Porsche but if I did I would be sneaking into the secrets room and pulling the file marked 'Intermediate Shaft Failure - The Truth!!'.
Will I get mine done - yes probably when the clutch needs replacing but not before.
I have never needed to be a 100% person to be able to sleep at night. The replacement would need to be a 'fit and forget' I would not be fitting one of the LN - now to be swapped again at 40K units.
keep it well serviced, drive it and enjoy it - that why you bought it.
Regards
GW
The failure of the IMS may be more to do with poor tolerance and variance due to lack of quality control at production of the parts. The failures in some cases may be caused initially by very small movement of the bearing housing when under pressure leading to increased stress and wear on the bearings themselves.
This then eventually causes the increase in freeplay that then goes on to destroy first the seal from the centre (leak of grease) then allows further accelerated deteriortion of the bearing and the bearing race proper.
It is not likely to be simply failure of the seals as bearings can survive with very small amounts of lubrication. The seals were supposed to be designed to withstand the higher running temps of the engine. There are reports of low mileage IMS failures and if the seal theory were true then they were pretty crap to go so soon and why would 92% be fine and 8% not be - there must be other factors involved.
That may be why there are differing mileages for IMS bearing collapse. It is because they are starting at different degrees of tolerance, some will be fine some a mircon out of some much worse etc.
That is also why Porsche were at first wipping away defective engines and replacing them because they did not know what was going on at first.
What 'premium' company would admit to poor quality components?
That could also explain why they remained silent for so long. They did not know what the longer term outcome would look like in numbers of failures. It would not have taken long for someone to extrapolate likely failure rates and the then ever decreasing numbers of failures as time went on.
That theory would also explain why not all IMS bearings have failed. Those that were within acceptable tolerance in regards to quality and 'fit' have stood the test of endurance as they were expected to.
We have all read the stories of bearings being 'upgraded' only to be told it was 'like new and seals intact'.
That may also explain why the instances of failure are tailing off, if you beleive the latest polls. The cars have been out of production for 10 years now but still, using a theoretical bell shaped graph it would show a peak of failure 'those that were always going to fail' and then reduce as those that were ok remain and others are replaced as precautions.
To cut the boring rantings of a madmans theory short. There are a number of factors at play. Quality of the parts. Maybe how you drive the car as low revs high gear combinations would increase the stress on the relevant parts of the engine, and if they were not up to par in the first place, increase the wear/damage.
On the upside. IF any of this crazy theorisation were true then the higher numbers of failures that have been seen in the past (some reports as high as 8%) will not be repeated in the future. Their are no guarrantees in life, other than death and taxes, but those cars that remain are less likely to fail because they were ok in the first place.
A caveat to that would be very late models that have very very low mileages whose less than perfect IMS has not had enough run time yet to fail.
A double caveat is that Porsche may at some point between 2001 and 2005 realised the issue, one would hope they have some smart engineers working for them, and changed production or supplier. That may explain the other theory that there were higher instances of failure in 2001 and 2002 cars - again all theory.
If I had the inclination it would be interesting to excel spreadsheet the model, production year and mileage for each IMS failure to see if there were really any peaks.
I do not work for Porsche but if I did I would be sneaking into the secrets room and pulling the file marked 'Intermediate Shaft Failure - The Truth!!'.
Will I get mine done - yes probably when the clutch needs replacing but not before.
I have never needed to be a 100% person to be able to sleep at night. The replacement would need to be a 'fit and forget' I would not be fitting one of the LN - now to be swapped again at 40K units.
keep it well serviced, drive it and enjoy it - that why you bought it.
Regards
GW
09-24-2015, 02:56 PM
#105
I've been saying for years that the low failure rate and wide range of mileages at the time of failure is a clear indicator that there are multiple variables at play. If it were down to a specific design flaw the failure rate would be much higher and the mileage range much narrower.