View Poll Results: Has YOUR car suffered an IMS failure
Voters: 1602. You may not vote on this poll
IMS bearing failure for your 996, Y or N? tell us (yr, 996 Mk1 or MK2 failure mode)
06-05-2021, 07:42 AM
#1246
Interesting discussion that flared up again. I'll introduce myself; my name is Boxman, called an idiot by some after suffering a $700 FVD Brombacher IMSB failure but catching it in time, who then decided to not go ludicrous 2000$+14000$-*****-to-the-walls but rather fit a 70$ off-the-shelf generic and sealed dual row bearing, sourced by yours truly, in his 996 after thorough cleaning.
This was over 2.5 years and over 20.000km ago.
'Some' people want you to believe that that was more like winning the lottery than doing science, and that my engine would not have lasted 1000km because 'glitter' will come and destroy your gonads. Yet here we are, and I am not even the only one.
'Some' would not even have sold me their 800$ bearing unless I had taken my engine apart, had it ultrasonically cleaned and basically rebuilt ad 14.000$ first, because their bearing was so good and strong that it 'only' needed that amount of work to not grenade immediately.
People can laugh and ridicule mentions of using off-the-shelf parts instead of a heavily marked-up set.. Yet here we are, with my 70$ off-the-shelf replacement apparently doing what neither the 800$ nor the >2000$ commercial option is capable of reliably doing in my dirty, foul and impure non-rebuilt engine.
Yes, I will document the inspection at the 40.000km service interval.
This was over 2.5 years and over 20.000km ago.
'Some' people want you to believe that that was more like winning the lottery than doing science, and that my engine would not have lasted 1000km because 'glitter' will come and destroy your gonads. Yet here we are, and I am not even the only one.
'Some' would not even have sold me their 800$ bearing unless I had taken my engine apart, had it ultrasonically cleaned and basically rebuilt ad 14.000$ first, because their bearing was so good and strong that it 'only' needed that amount of work to not grenade immediately.
People can laugh and ridicule mentions of using off-the-shelf parts instead of a heavily marked-up set.. Yet here we are, with my 70$ off-the-shelf replacement apparently doing what neither the 800$ nor the >2000$ commercial option is capable of reliably doing in my dirty, foul and impure non-rebuilt engine.
Yes, I will document the inspection at the 40.000km service interval.
Last edited by User 63031; 06-05-2021 at 07:47 AM.
06-05-2021, 08:05 AM
#1247
Racer
If you pay much more than $20* you are just being ripped off, that is the reality. You can pay as much as you want, it won't be any better, you are just paying the middle man.
Porsche was unfortunate to have a few bad bearings in production, other mfg also have problems with poorly produced parts. That doesn't mean the design and use of a ball bearing is wrong.
Some of the "advice" here (like removing the grease seal) is directly bad for the longevity of the bearing.
If you have read my investigation I arrived at pretty much the same conclusion as Porsche: Generally don't do anything. If you have the gear box off for whatever reason you can check it and replace if it's worn.
Look in this thread how many have pulled a perfectly fine bearing, gives a nice overview of the misadvise people are getting. This IMS thing is way overhyped.
*for a 6204 bearing.
Porsche was unfortunate to have a few bad bearings in production, other mfg also have problems with poorly produced parts. That doesn't mean the design and use of a ball bearing is wrong.
Some of the "advice" here (like removing the grease seal) is directly bad for the longevity of the bearing.
If you have read my investigation I arrived at pretty much the same conclusion as Porsche: Generally don't do anything. If you have the gear box off for whatever reason you can check it and replace if it's worn.
Look in this thread how many have pulled a perfectly fine bearing, gives a nice overview of the misadvise people are getting. This IMS thing is way overhyped.
*for a 6204 bearing.
Last edited by Nick_L; 06-05-2021 at 08:19 AM.
06-05-2021, 01:14 PM
#1249
Rennlist Member
Boxman glad your risk taking paid off for you. If you place a low regard/value on the engine, you can save a lot of money taking risks like that.But advising people to take those kinds of risks is a recipe for disaster.
I survived a near miss by lightening one time that knocked me to the ground while putting my boat away in a lightning storm.
Nick, using a pressure oil feed to the IMSB has no consequences to the oiling system. I did this over 40 years ago to pressure feed a turbocharger (and set 2 World Records with it) and has been done millions of times since to just about every engine design on the planet with no consequences to the oiling system... You are nuts and know nothing of what you talk about..
I survived a near miss by lightening one time that knocked me to the ground while putting my boat away in a lightning storm.
Nick, using a pressure oil feed to the IMSB has no consequences to the oiling system. I did this over 40 years ago to pressure feed a turbocharger (and set 2 World Records with it) and has been done millions of times since to just about every engine design on the planet with no consequences to the oiling system... You are nuts and know nothing of what you talk about..
Last edited by Porschetech3; 06-05-2021 at 01:44 PM.
06-05-2021, 03:12 PM
#1250
Funny how every non-LN fix is classified as a 'risk' and winning the lottery. I do not consider myself special enough to win lotteries, these decisions are made based on simple mechanical understanding and reasonable risk-reward. What is your basis for calling my approach a 'recipe for disaster'? That implies a near-certain failure rate where I just got 'lucky', is this what you mean, with your almost-struck-by-lightning remark? Can you substantiate any of that? Can you also point me to some anecdotal stories that went (roughly) my route and had a catastrophic failure afterwards? Basically the same approach as mine.
Do not take the confirmation bias too lightly. With how people are fearmongered into installing an LN bearing + pre-qual, these forums by definition are not heavily populated by people who go my route, regardless of their bearing having grenaded before it. Then again, can you point me to abundant failures of the Pelican bearing approach?
Just because this is an LN engineering echochamber, doesn't mean that not coughing up 14k $ for fixing a 1% failure mode of the original IMSB (for the dual row at least) permanently is suddenly a 'risky' decision. Especially when these engines D-chunk left and right at the same time. You might fix 1 failure mode, but this engine has countless.
So please substantiate what anecdotal evidence (of other forummers unaffiliated with LNE) you are basing calling my approach 'risky' and 'disastrous' upon.
Do not take the confirmation bias too lightly. With how people are fearmongered into installing an LN bearing + pre-qual, these forums by definition are not heavily populated by people who go my route, regardless of their bearing having grenaded before it. Then again, can you point me to abundant failures of the Pelican bearing approach?
Just because this is an LN engineering echochamber, doesn't mean that not coughing up 14k $ for fixing a 1% failure mode of the original IMSB (for the dual row at least) permanently is suddenly a 'risky' decision. Especially when these engines D-chunk left and right at the same time. You might fix 1 failure mode, but this engine has countless.
So please substantiate what anecdotal evidence (of other forummers unaffiliated with LNE) you are basing calling my approach 'risky' and 'disastrous' upon.
Last edited by User 63031; 06-05-2021 at 03:15 PM.
06-05-2021, 03:43 PM
#1251
Rennlist Member
Yes, I have seen that done successfully and also seen it done unsuccessfully. Yes it is very risky and the owner must have a low regard for the engine.IMHO it is bad advise.
It would be similar to taking a 1/2 teaspoon of brake shavings from a brake lathe and dropping it down the oil fill tube. If you did that to 10 M96 Porsche engines, even after flushes and multiple oil and filter changes, how many do you think would be unaffected by it? Would your answer be 10?
It would be similar to taking a 1/2 teaspoon of brake shavings from a brake lathe and dropping it down the oil fill tube. If you did that to 10 M96 Porsche engines, even after flushes and multiple oil and filter changes, how many do you think would be unaffected by it? Would your answer be 10?
Last edited by Porschetech3; 06-05-2021 at 03:48 PM.
06-05-2021, 04:41 PM
#1252
Quantify “very risky” please.
No offense, but your statements are baseless, grounded in gut feeling and nothing more, until the time you quantify them and provide sources for your anecdotal evidence.
I have no low regard for the engine, rather I was very meticulous in the process. You are entitled to your opinion but let’s not mistake that opinion for a fact.
It would be similar to taking a 1/2 teaspoon of brake shavings from a brake lathe and dropping it down the oil fill tube. If you did that to 10 M96 Porsche engines, even after flushes and multiple oil and filter changes, how many do you think would be unaffected by it? Would your answer be 10?
Added to the sump, with oil filter system in good shape, the grit will not see the journal bearings. It will not see the IMSB since it is sealed. Frankly, it will eat an LN Retrofit in no time, who would have thought...
If grit in the sump was so incredibly critical for this engine, why bother with the filter at all? According to you it’s game over whenever any wear metal hits your sump oil.
Then again, what would your answer be? How many engines? You seem uncomfortable quantifying your statements, why is that?
Last edited by User 63031; 06-05-2021 at 04:43 PM.
06-05-2021, 05:20 PM
#1253
Rennlist Member
I was really looking for to your answer, it was a simple question that you have undoubtedly though a lot about and should have been able to give a 1-10 answer to very easily, why did you avoid it?
No I don't carry around evidence/pictures to back up my statements unless I am going to court to be an Expert Witness, so your out of luck.
Yes the debris from a failed IMSB will be thrown around by the IMS and timing chains and land on the lower part of the cylinder while the piston is up top and will lodge between the piston and cylinder wall rubbing up and down even before it makes it to the sump Then it gets picked up by the pick-up tube and carried to the oil pump where it is crushed between the gears before finally making it to the oil filter to be caught.Even then the filter will only catch particles of 20 microns and bigger.This is not opinion, it is a fact.
Yes I have seen this damage from the debris with my own eyes.
Now how about that 1-10 opinion?
No I don't carry around evidence/pictures to back up my statements unless I am going to court to be an Expert Witness, so your out of luck.
Yes the debris from a failed IMSB will be thrown around by the IMS and timing chains and land on the lower part of the cylinder while the piston is up top and will lodge between the piston and cylinder wall rubbing up and down even before it makes it to the sump Then it gets picked up by the pick-up tube and carried to the oil pump where it is crushed between the gears before finally making it to the oil filter to be caught.Even then the filter will only catch particles of 20 microns and bigger.This is not opinion, it is a fact.
Yes I have seen this damage from the debris with my own eyes.
Now how about that 1-10 opinion?
Last edited by Porschetech3; 06-05-2021 at 05:41 PM.
06-05-2021, 06:04 PM
#1254
I'll wait for your anecdotal evidence - a link to a thread will suffice - and otherwise bury the discussion with you right here. I think I asked you to substantiate your claims before you asked me about your hypothetical, but you had not answered any of my questions yet - fair is fair, no?
Debris laden oil, even if you have it, doesn't flow upstream of oil flow, period. Go have a look at the diagrams yourself. Splash might make it to the cam sprockets and no further - the IMSB is mostly isolated from the crankshaft with splashguards (quick source of a teardown for you), and splash will not make it to the cylinder walls like that. And even if you would hit the astronomically correct bump and a piece of debris (metal, tensioner pads) makes it on there, there are still pressurized oil squirters constantly providing a flow of absolutely clean oil to the walls which washes that away in just 1 stroke. If you had actually seen the block from the inside, you would not have made the rest of your outlandish claim.
Debris laden oil, even if you have it, doesn't flow upstream of oil flow, period. Go have a look at the diagrams yourself. Splash might make it to the cam sprockets and no further - the IMSB is mostly isolated from the crankshaft with splashguards (quick source of a teardown for you), and splash will not make it to the cylinder walls like that. And even if you would hit the astronomically correct bump and a piece of debris (metal, tensioner pads) makes it on there, there are still pressurized oil squirters constantly providing a flow of absolutely clean oil to the walls which washes that away in just 1 stroke. If you had actually seen the block from the inside, you would not have made the rest of your outlandish claim.
Last edited by User 63031; 06-05-2021 at 06:25 PM.
06-05-2021, 06:43 PM
#1255
Rennlist Member
yea you won't me tp prove what I already know, put the burden on me, yet you have so many opinions, but when I try to coral your opinion into something specific that can be analyzed, like how many engines out of 10 do you think would suffer no consequences from 1/2 teaspoon of debris, you balk.
Yes the IMSB debris will make it into the cylinders mainly number 6 because it is closest to the IMSB. You should have seen the 40AE with 30k miles on it with a failed IMSB, Number 6 cylinder was scratched all to hell.
Not only will the cylinders get scratched but it will travel up the timing chain to the bank 1 head and go into the bank 1 scavenge pump and scratch it all up, all this before going into the sump and oil pump and finally the oil filter.
And if your not really up on debris damage it can do even in particle sizes smaller than the filter can catch, the most damaging partical size for bearings like rod and crank bearings is 10 microns. 10 microns will not be caught by the filter, is too small to lodge outside the bearing, too big to just flush through the bearing clearance, but just right to be trapped in the bearing and cause damage.
You can choose to ignor these facts and consider yourself lucky, but repeating it might influence 10 others to ignor the facts and would be the same as giving your 1-10 opinion as a 10 meaning that your opinion is that 1/2 teaspoon of debris poured down the oil fill tube would cause no harm if you just flush it out and change the oil a few times.
Bad advice
Yes the IMSB debris will make it into the cylinders mainly number 6 because it is closest to the IMSB. You should have seen the 40AE with 30k miles on it with a failed IMSB, Number 6 cylinder was scratched all to hell.
Not only will the cylinders get scratched but it will travel up the timing chain to the bank 1 head and go into the bank 1 scavenge pump and scratch it all up, all this before going into the sump and oil pump and finally the oil filter.
And if your not really up on debris damage it can do even in particle sizes smaller than the filter can catch, the most damaging partical size for bearings like rod and crank bearings is 10 microns. 10 microns will not be caught by the filter, is too small to lodge outside the bearing, too big to just flush through the bearing clearance, but just right to be trapped in the bearing and cause damage.
You can choose to ignor these facts and consider yourself lucky, but repeating it might influence 10 others to ignor the facts and would be the same as giving your 1-10 opinion as a 10 meaning that your opinion is that 1/2 teaspoon of debris poured down the oil fill tube would cause no harm if you just flush it out and change the oil a few times.
Bad advice
Last edited by Porschetech3; 06-05-2021 at 06:45 PM.
06-05-2021, 08:09 PM
#1256
I will not waste my efforts on someone who only asks questions in return but never answers any to begin with, yet attacks his opponent for not answering as a result of that. I know your type. You balk first, then tell the other they balk 
. Little substance, usually.
You answer my questions, and I'll tell you how many engines I think will die.
You won't, so nice day to you.
. Little substance, usually.You answer my questions, and I'll tell you how many engines I think will die.
You won't, so nice day to you.
Last edited by User 63031; 06-05-2021 at 08:19 PM.
06-05-2021, 08:27 PM
#1257
Rennlist Member
I will not waste my efforts on someone who only asks questions in return but never answers any to begin with, yet attacks his opponent for not answering as a result of that. I know your type. You balk first, then tell the other they balk . Little substance, usually.
You answer my questions, and I'll tell you how many engines I think will die.
You won't, so nice day to you.
. Little substance, usually.You answer my questions, and I'll tell you how many engines I think will die.
You won't, so nice day to you.
06-05-2021, 08:40 PM
#1258
Funny how every non-LN fix is classified as a 'risk' and winning the lottery. I do not consider myself special enough to win lotteries, these decisions are made based on simple mechanical understanding and reasonable risk-reward. What is your basis for calling my approach a 'recipe for disaster'? That implies a near-certain failure rate where I just got 'lucky', is this what you mean, with your almost-struck-by-lightning remark? Can you substantiate any of that? Can you also point me to some anecdotal stories that went (roughly) my route and had a catastrophic failure afterwards? Basically the same approach as mine.
Do not take the confirmation bias too lightly. With how people are fearmongered into installing an LN bearing + pre-qual, these forums by definition are not heavily populated by people who go my route, regardless of their bearing having grenaded before it. Then again, can you point me to abundant failures of the Pelican bearing approach?
Just because this is an LN engineering echochamber, doesn't mean that not coughing up 14k $ for fixing a 1% failure mode of the original IMSB (for the dual row at least) permanently is suddenly a 'risky' decision. Especially when these engines D-chunk left and right at the same time. You might fix 1 failure mode, but this engine has countless.
So please substantiate what anecdotal evidence (of other forummers unaffiliated with LNE) you are basing calling my approach 'risky' and 'disastrous' upon.
Do not take the confirmation bias too lightly. With how people are fearmongered into installing an LN bearing + pre-qual, these forums by definition are not heavily populated by people who go my route, regardless of their bearing having grenaded before it. Then again, can you point me to abundant failures of the Pelican bearing approach?
Just because this is an LN engineering echochamber, doesn't mean that not coughing up 14k $ for fixing a 1% failure mode of the original IMSB (for the dual row at least) permanently is suddenly a 'risky' decision. Especially when these engines D-chunk left and right at the same time. You might fix 1 failure mode, but this engine has countless.
So please substantiate what anecdotal evidence (of other forummers unaffiliated with LNE) you are basing calling my approach 'risky' and 'disastrous' upon.
'm more than happy to address your question, if you don't cop-out.
Last edited by User 63031; 06-05-2021 at 08:44 PM.
06-05-2021, 08:51 PM
#1259
Rennlist Member
Wait, just one question at a time....and no I'm not going to look up "evidence" for you, you either believe me or not, You can even call it a "lie" if you see fit.
Maybe we should start out with presenting our Curriculum Vitae, what is yours?
Maybe we should start out with presenting our Curriculum Vitae, what is yours?
06-05-2021, 09:21 PM
#1260
Nah mate, I'll pass on your little kindergarten dance. You have nothing to show, that's okay. My questions were clear, you continue to dodge them, try not to be so surprised about my unwillingness to answer any of your questions in return.
"Either believe me or not" - well that's an easy one. I have little reason to believe loose claims from randoms on the internet at face value, especially if they actively refuse to substantiate them when asked. I don't consider you an exception, hope you can live with that
I doubt this conversation will go anywhere constructive so I have no intention of continuing it - you're behaving like a child, to be honest. Have a good one anyway.
"Either believe me or not" - well that's an easy one. I have little reason to believe loose claims from randoms on the internet at face value, especially if they actively refuse to substantiate them when asked. I don't consider you an exception, hope you can live with that
I doubt this conversation will go anywhere constructive so I have no intention of continuing it - you're behaving like a child, to be honest. Have a good one anyway.