1999 996 IMS ****if this subject bothers you then do not read***

After all of my research I come away with a pretty idea of what we are talking about but I want to get your insight. So the 1999 has the double row IMS along with some of the 2000 cars. After that Porsche really screwed their customers by stepping down to a single row. I believe this is where and when all of the problems began. To make matters worse in 2006 not only did they stay with the single row while supposedly making it a bit stronger stronger but it cannot receive any cure without ripping down the motor, in other words it is internal. Nothing new there, right? To the point my research tells that 1% of the double row cars had a problem while the single row cars up to 2006 are at 8%ish failure which is very high I think. I don�t want to replace mine if I don�t have to. This thread is more about something I just uncovered for myself. There is or was a monitoring system available. Has anyone installed this? What do you think of it? How much did you pay to install or did you do it yourself? I see it used to be around a grand. ***Disclaimer*** If you do not like discussing this topic then just move along please don�t post negative comments here. I know this subject has been beaten to death and it deserves to be. We are discussing the life and death of our engines. I�m trying to gather facts so I can decide what course of action I am going to take. Newcomers to the 996 should know the facts and the options. Enjoy!

IMS Guardian. It�s in the Wayne Dempsey 101 projects book. No idea if it is still available, try LN Engineering and Pelican Parts. Based on the article, it looks like it just goes in place of the drain plug, and the wires are run up into the cabin, where you grab power out of the fusebox, and install the indicator into a switch blank in the horseshoe. Sounds like a two bananna job to me. https://www.pelicanparts.com/techart...S_Guardian.htm

The system you are talking about was made by flat six I think (I might be wrong) but is now discontinued. I believe it worked by having a different drain plug in the sump that was magnetic with 2x probes, if the IMS started failing the idea was to attract any metal flakes which would stick to the magnet and bridge the two probes, completing a circuit and putting a light ON in the dash. My guess is it was not a great solution; as by the time you got a warning your engine might be full of damaging particles. These days its just a better option to drop your tranny, put a good aftermarket IMS bearing in and a new clutch/RMS and forgettaboutit. I did mine myself in my less than stellar garage space, not too difficult. I have a ceramic LN engineering IMS in mine, dual row. I also have powerful magnets wrapped around my OEM filter housing which I check on each 5-6k mile oil change, they capture anything ferrous so I can check it. Last oil change was a small amount of smooth ferrous spooge which is good...

General question, what is considered a high failure rate for a car?

8%

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Yes, 8 is high. Maybe I should have worded it differently. Is 1% normal, should it be .5% or what is the accepted rate at which cars will have issues?

I have heard of Porsches with low mileage, high mileage and in between having failures. Obviously if your Porsche falls in the 1% group, and there were over 20,000 '99 Boxsters produced, then there are perhaps at least 2000 that could have failed bearings. Since you will never know whether your fall into the group with failures or the group without failures, it seems logical to replace the IMS, unless you feel comfortable living with the risk. I decided to mitigate risk on my 9,000 km '99 Boxster, because I wasn't happy with the risk. By the way, the bearing was in perfect condition on replacement. Sorry, I was just reading about Boxsters, and then realized I was in the 996 forum, but the logic still applies, which is why on my 996 targa, I was either buying a car with a replaced IMS bearing or planning to replace it (as I bought the targa used, unlike the Boxster which I bought new).

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Sorry to tell you that 1% of 20,000 is 200 car not 2000. 2000 would be 10%.

$400 and five hours to "monitor the potential problem" or $2500 and not worrying about it again. What baffles me is all the people who own these cars and then are paranoid about the IMS??? Information on this is abundant on the internet show why wouldn't you buy a year that is not problematic? Personally for me 2-3k is cheap money for peace of mind, just replace it.

I suspect it is a very small segment of the porsche owning population: probably more prevalent in people that hang out in model specific internet forums and have fears reinforced by the echo chamber. The same people that are losing sleep over this are probably going to start losing sleep over bore scoring next. A lot of the rest of us just enjoy our car. I suspect we are underrepresented in the self selected group that posts these questions and comments.

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Makes sense. But Porsche owners - and what they consider enjoyable - vary. For me, the 996 represents an interesting, moderately complex, and notably elegant machine - that for various reasons can be had for about half what it should cost. I feel that when you own any machine like that, you owe it a "duty of care". If it has a weakness (as it does), it becomes part of your duty to address that - perhaps the more so because that weakness is a big part of the reason the car was affordable. Having installed the IMS Solution (an interesting project) I find the car more enjoyable to drive. I did my part by giving it the care it needed (along with clutch, RMS, AOS, etc.); in return, it does its part on the road - conspicuously well. I would not enjoy the driving as much if I felt I hadn't held up my side of the bargain - it would feel disloyal, and the car would not owe me the performance it consistently delivers. I don't claim all this is fully rational, nor do I condemn alternate views. But this is how my thinking runs.

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100%

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Im not sure what you mean here. With each year that passes it becomes more and more evident that some cars were prone to failure while others are not. So now it becomes a gamble while I enjoy my car. I am not really paranoid about the IMS. I am more curious. LN engineering is not the only game in town and I have been doing a ton of research on this very subject. I myself am trying to decide if I should go for it or not. Meanwhile it is winter in Massachusetts and I do not have a garage. I cannot do anything until the weather improves. I was hoping that more people would join this thread rather than the people with the mindset in this quote. How do you know that I really want to swap the IMS and I am looking for more support in deciding if it�s the right thing to do to my car. Do you really think that if I rip my car apart to replace the IMS and find a perfectly in tact IMS I am going to be happy about that? Hell no I am going to be pissed off big time. I have done enough playing around with cars in my life that taking part the drive train does not excite me one bit. I�m not afraid to drive it either. Just a question of making my final decision for this year anyway. I have the 1% car not the 8%. If I had the 8% there would be no decision. It either gets done or I would get a new car. I do appreciate everyone responding to this thread. Please keep them coming.

Do whatever makes you happy. I did the LN dual row classic in my 2000, and haven�t touched the IMS bearing in my 2002. The 2002 has an AT replacement with the latest large IMS bearing, which would require splitting the cases to replace. You�ll never know if you have one of the unluckily ones unless and until it happens. Worrying about it won�t change that. Preemptive replacement might help you dodge a bullet on this particular mode of failure. High or low percentages of historic failure rates have no impact on the likelihood of the failure on your car. Fix it or don�t. Worry about it or don�t. Keep rehashing the most over discussed topic on this forum or don�t. It doesn�t really matter to me. You roll the dice and you take your chances.

I am sorry you see it as “rehashing”. I think your missing part of the point. It’s 2019 and I am looking for more data. CDS72911 while you may not fully realize it you just provided me with recent up to date data. I’m sure others have more data. Like how many of us have been in there to change the IMS only to find on that is totally fine? In part this is the information I am looking for in particular relating to the double roller but not completely. I think if we look at this way there is more current information that can be provide along with which IMS solution did you use? There is a huge spread in cost and not necessarily the same part. Some manufacturers use different material. Again more data. When Insearch this forum an absolute ton of data shows up. I spent several hours reading through it. Some of it 10 years or more older. That is not current as far as I am concerned. It is my hope that folks with a negative attitude towards this subject just move along as they really have noting meaningful to contribute.

That's exactly what you want to find, once it' starts shedding it's to late.

Data: in my 2000 carerra 2, I used the LN Engineering dual row classic, replacing another LN Engineering dual row classic installed in 2015. The bearing removed was in perfect condition, but replaced due to service interval specifications. I did it preemptively because I had the transmission off to replace a second gear synchro, so I was already most of the way there.

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I think this is a very sensible approach and I would absolutely do it if I needed to pull the tranny.

Not mentioned here, is the car a stick or auto? If it is a stick then at 1% wait until you need to do the clutch and just add the bearing. Does not cost as much then. BTW, I was one of the lucky 200 with my 99.

https://tenor.com/view/horse-dead-beating-gif-9285411

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The 996 Mk2 with Tiptronic requires removing both the engine and transmission together before they can be split to access the IMSB. That means it is more like $4K to do the job.

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Would you consider this to be �disposable income�? Or do you just have money to burn? My IMS will be getting changed when I do the clutch. This is basically the best approach from what I can tell. I�m still keeping an open mind.

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No, you are missing the point. This has been discussed to death and newcomers keep bringing it up again and again. These cars are approaching 20 years old. If you want to be sure you'll never have an IMSB failure, have the IMS Solution installed. End of story. No further research or discussion is necessary.

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No, it is a big hurdle for me, and I haven't gotten it done. This is one disadvantage with the Mk2 Tiptronic vs a manual. The manual trans has regular maintenance: change the clutch, and while you're in there, do the IMSB, which kinda keeps the cost lower for the periodic IMSB replacement. With the Tip there is no concept of "periodically remove the trans" so the IMSB replacement cost is strictly for that. My understanding is the Mk1 Tiptronic can be removed by itself without removing the engine.

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Not true about the MK-I Tiptronic - the engine and transmission need to be dropped together as well. You can take advantage of some shared labor by having them do the IMS, RMS, and AOS at the same time. If you're not a DIYer and you still have the original coolant expansion tank, have them swap that out at the same time. When I had the IMSB changed in my MK-I Tip Cab nine years ago, they did the RMS, low temp thermostat, and X51 oil pan at the same time. Now the shop automatically does the AOS too. It's around a $4k bill but it takes care of a lot of potential issues.

Maybe an admin can put this thread with the 350+ comments here: https://rennlist.com/forums/996-foru...his-first.html

OP - I’m also new here but had been researching 996 for a long time before buying one. Specifically I was looking for a ‘99 model for a couple of reasons. The one that I found just happened to be very close to needed a clutch and had a small leak at the RMS, so it was a no brainer to do an IMS replacement and RMS replacement along with a new clutch. The bearing that came out looked like brand new. Likely if I had found a lower mileage car that did not need a clutch I would have waited. On the other hand, if I bought a 2001 I would probably change it right away. But everyone’s tolerance for risk is different. Daryll

May or may not be relevant here but my 2002 had a factory engine swap done in 2005. That replacement engine had the Porsche update - namely a bigger bearing which indeed can not be extracted and replaced like the earlier bearings. Once I learned I had the big bearing I put up a post asking for hard evidence of any big bearing failing . I'm still waiting for any evidence anywhere to show that any big bearing motor has ever failed from a IMS bearing failure. My car has 264,000 km total on the clock - 194,000 of those on the replacement engine. I've been sleeping pretty soundly since I bought this car 10 years.ago. just sayin' -

IMS remediation is all about risk tolerance. 1999/early 2000, looks like 1% failure. Later looks like an 8% failure. I don’t like risk. So, when I purchased my 45000 mile 2003, I had already budgeted for the Solution. Why the expense of the Solution? 1. Lifetime, never needs replacement. If I ever resell, It is obvious that it is the Solution. 2. Regardless of the IMS remediation approach (roller bearings, ball bearings, ceramic bearing, Solution) you are in to labour of around 15 hours. 3. While you are in there, change AOS, Clutch, RMS, maybe flywheel. Again set costs. 4. The Solution, including the extra couple hours is around $2k. Replacement bearing is $500 to $1000. 5. Simple math is that Solution is $1k to $1.5k more than other remediations. 20% more. Since I am not risk tolerant, I chose the Solution. Yes, my IMS bearing was fine. I have pretty complete service history too showing at least annual oil changes. Oh, I even have a 2017 Porsche branded battery. Service records are almost exclusively from Porsche dealers. Should I have waited, maybe.

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997 share the same bearing, they fail too.

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Oh I am well aware that people think the 997 shares that bearing, but thats not entirely true. They actually changed over halfway through 2005. The first half of 2005 used the old bearing. I found this out when my good friend bought a 2005 S (yes with the 3.8 litre) and it had a LNS ceramic bearing installed. Did some research.... It's easy to say that the big bearings fail, but it s�ems it's really really hard to actually find one that's failed. Not all 997 had the big bearing. So just finding a 997 that has had a failure isn't enough, it has to be a late 2005, a 2006, or a 2007 model. *Please, find me one that's failed. I'll wait.

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Sorry to tell you that sweating relatively inconsequential dollars when the down side is a new engine makes even less sense.

Data: I bought an early build (1/98) 1999 C2 late last year. It has a dual row IMS from the factory. No service history and theres a bunch of grease caked on different parts of the motor but it runs fine and doesnt over heat. $2-3K to install LN bearing and other parts (while i'm in there) $20-25K to get Flat6 to rebuild my motor (before a failure, or the price goes up after a failure) $5-10K to install a used motor when factory motor blows up $7-12K to swap it with a LS motor (depending whos kit you use and who does the swap) I paid $8K for my car. I'm on the fence about which way I want to go in terms of long term maintenance... A swap is really high on my list since my car doesn't need extra ECUs, etc and it seems pretty straight forward (economical). Especially if my stock motor is work $5-8K on a good day... My other option is to run with what I brung... I've seen plenty of cars online with original bearings go well into the 200K mile mark. I change my oil every 3K miles or 6 months on all my cars and thats the first step in keeping a healthy IMS from what I gather.

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Not sure where you got your information from but, it's well documented...The large 997 bearings have failed! Rare yes, I have one... Have you read through this? ** https://rennlist.com/forums/997-foru...e-mode-67.html Your thoughts? I'll wait.

The LN product, and ideally - any IMBS remediation is a proactive task to remove a very high failure item. I installed the LN bearing in my 99, mag drain plug, full flow filter. The bearing that came out was in perfect condition, which was a good thing. The monitoring device was the Guardian. I didn't install this(not sure it's avail). In some helicopters we have a 'chips' detector which will advise the pilot in-flight of a high metal content in the tail rotor and gearbox allowing the pilot to land proactively. In the 996, this would possibly allow the engine to be shut off in time before serious damage is done. Not sure if that works, because in helicopters the trans is taken apart and completely rebuilt in the event of a chips light coming on. The 1% failure rate in terms of modern car production is outrageously high. Most mfg, like Toyota consider anything higher than six sigma(~0.0003%) is unacceptable. No matter the 996, install the full flow oil filter kit(just in case), change oil often, use good oil, and for either of the bearing solutions, install it, or have it installed by a qualified shop. YMMV, objects in mirror, contents have settled, etc.

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from that thread: "The incidence of failure with a 2006-2008 M96 or M97 engine that have this larger IMS bearing is highly unlikely with estimates being about a 1% failure rate, if not less." that's from the guys at LNS. Good enough for me.

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You have it all wrong Brian. If you find the bearing to be in good shape, that's what you want! I know that can seem counter intuitive, but if the bearing is shedding metal then it's TOO late, you'll have to rebuild the motor and that it going to cost you as much as the car is worth in many cases. Many people believe that if you find a "perfect factory bearing", then it means the whole IMS bearing was a big hoax brought on by aftermarket bearing companies trying to fear monger there way in the owner's pockets. There is no way to accurately quantify how many cars have failed from problem bearings in recent history. Many people quote the 10 year old class action "settlement" and that data is no longer practical because all of the M96 and M97.1 cars are out of warranty and data is not shared by indies that do work on these cars. Some would say you could get an idea by looking about the 30,000+ sales of retrofit production from LN Engineering and that's true, but still, in all fairness, you really can't get solid figures either way. You just have to use common sense. If Porsche made three versions of the bearings and then you'd probably have to scratch your and say, there probably was some serious problems with these bearings. I think most people would agree and say that if you own a 996 with the original bearing, closely monitor your oil and send a sample to Blackstone or Speed Dianostics for an oil analysis. If you see any precursors in the report, then get the bearing changed out asap. Most people change them out with clutch services which make a lot of sense. Also, save the labor and have the installer replace the RMS and AOS while they're in there. Good luck!

When I took out my orig IMSB, I took a video, including a shot of the VIN of the car. When I sold the car, I included that video clip showing the good bearing being removed, and I gave the old bearing to the buyer because I didn't care about the 'warranty' offered by LN. It was far more important to me to pass along a perfect removed bearing with the car. The buyer was very happy with that arrangement. Edit: Yes, I did the clutch, PP, RMS, but not the AOS, which maybe I should have, but it can be replaced with the trans in the car, unlike the other internals.

Oops, wrong thread, admin please delete.

You�d be pissed off that you had a perfectly qualified engine for an IMS Retrofit procedure? Let me guess, you don�t realize that the procedure was never developed as a repair for an already failing engine, that had already seen collateral damage from contaminated engine oil. Right?

My point is that in a 99 996 it is only 1% necessary yet so still feel all the propaganda put out there. 8% is another story.

I don't think you clearly understand the stochastic process. At the time of the lawsuit, or just before the failure rate of 1% represented the population of cars built. Each chosen period(lets use 'year' because it's convenient), another 1%. So the first period left 99% undamaged cars, and the next period it was down to 98%(two years, 2% of the orig population), third year, another 1% for a total now of 3% of the orig population and so on and so forth. The only way to not have any failures is to not start any engines. This will stop the stochastic declining balance of undamaged cars. But - as this is nonsense, each period(year) another group fail. Of course, there is going to be some variability in the process due to failure modality, and exposure. As cars are treated better, the failure RATE may go down, but it is still stochastic. Another statistics point to make. Just because one owns a 996 that wasn't affected last year, that is no throw of the dice that says this year, or next year might be one's turn in the IMSB barrel. Each year, we have several posters right here on this forum with a new IMSB story: https://rennlist.com/forums/996-foru...ld-you-do.html And this only represents a small fraction of the 996 community.

You do know that your bearing is 20 years old, right?

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In the M9X Hands- On Rebuild School that had a worldwide attendance, and was just finished up today, several forum members got to see a �1% 1999, 996 engine�. The dual row IMS Bearing they removed from the failed engine was at Stage 3 failure. @AnthonyGS held the shaft in his hand, as did 1/2 dozen others. That engine was a late 1999 with it�s original dual row bearing. Keep in mind that the fact finding for the Eisen Vs Porsche class action suit began in 2010, and continued through 2011. This data only included engines that had gone back to Porsche with failed bearings, so it was not a very good litmus paper for all the engines that had failed. I know this, because I know how many of those engines we had seen, and the fact that the questions we were asked never included �How many failed IMS Bearings have you seen?� That said, The data is old, and out of date. The suit was settled in 2013. At the end of the day people believe what they want to believe. Its a 1% failure, till you end up as part of the 1%, at which time it will make a 100% impact on your bank account.

As the man at FSI is telling you I just pulled the IMS shaft along with classmates from a 99 engine this past week. I gave the bearing a spin and came to the quick conclusion the bearing was bad. You could feel the metal on metal grinding and excessive sideplay due to the excessive wear. That engine was only a few more starts from being a more damaged core. You can see the IMS on the cart in this photo. Your fallacy is in thinking only 1% of the bearings will fail ever. A bearing is not an infinite life part. Since my 996 and 986S share so much in common I�m currently looking for a spare engine core. I�m also going to do waterpumps, chain guides and IMS bearings in both cars in the next six months to prevent issues. The 996 has an LN bearing and I have the original dual row too.

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@AnthonyGS you didn�t realize how much of a Unicorn you were privelaged to disassemble.... I mean how often does someone get to actually touch 1% of the 996s built with a dual row IMSB? Meanwhile, the other 1/2 dozen attendees disassembled the same exact engine, but it was equipped with a classic dual row LN Enginerring IMS Retrofit. That bearing had lived through intermix, and looks so good that it could be reused as is, if someone wanted. 14 more people now hold first hand experience with these failures, and successes. They�ll be pretty hard to argue with.

I actually own a 00 996 built with a dual row IMS bearing. I have the original bearing and it was still good when the PO had it serviced with a LN bearing. I�m still considering the IMS solution for this car. I don�t know which bearing is in my 00 986S but I�m going to find out next fall/winter and service it.