IMS bearing replacement

I was at one of Jake Raby's sites - he has some great M96 engine articles there, like this one on replacing the IMS bearing: http://www.flat6innovations.com/savi...e-ims-retrofit Just thought people would find it interesting.

thats a good write up - if I change the clutch, I am putting in that new bearing - no question about it

Doesn't cost something like $4K to retro fit it?

the bearing ? - NO its like under $1k IIRC

Here's a good right up, best IMS info I've seen. It's LN Engineering, who I think partnered or spearheaded/designed the kit, but Flat6 is part of the writeup too . I'm definitely doing it retrofit kit ($500-$600) when changing the clutch next. The "best" kit is to send in your IMS and have them put on the super-awesome kit (which costs more, and you need to send in your IMS after a tear down), but I think even the retrifit will give the IMS a much improved life. http://www.lnengineering.com/ims.html

1) $ 500-600 for IMS bearing upgrade from LN and upgraded bolt assembly 2) approx. $ 1,000 from a dealer to do the labor due to teardown/All labor, even when clutch mechanism is already out...

What about the bearing removal tool? How much does that cost?

They loan it out on the cheap, their pricing is hidden somewhere on their site.

I was on Peavy's link. The tool is $29 to rent for 3 weeks. But I think the whole IMS bearing replacement kit is nearly $600.

A few clarifications/ explanations: The IMS procedure and bearing have been a mutual development between my company and LN Engineering, we have been working together on similar projects for over a decade. Charles from LN designed the replacement hybrid silicon nitride bearing and together we completed the procedures of bearing extraction and replacement. Over time several different methods of bearing extraction have been executed and as we speak a new version of the tooling is being tested that is easier to use and will not require rental hassles. This puller will come with the bearing kit and will allow for much simpler bearing extraction. When this puller is completed and has been fully tested I will then produce a DVD to supplement the kit that covers bearing extraction and reinsertion as well as all other pertinent aspects of the IMSR procedure. I have held off on producing this until the new tooling is completed as it changes the entire process, for the better. The IMSR processes can be accomplished for under 1K if you are a DIY Porsche enthusiast, this will cover the parts only for the process along with the current tool rental costs. If you depend on your local shop to do this work, the going rate is hourly but generally comes in at 3,500-4K and slightly more if the car is a C4 due to aded labor. I applied the first retrofit bearing and we have done more than anyone else, along with the testing of the entire series of bearings as they have evolved. The very first bearing installed is seeing service in my Boxster while bearings #2 and 3 are also in service in our test cars, including my Wife's Land Speed 996 that she piloted to 149.281 MPH last weekend in the standing mile at Maxton NC. We have done these processes dozens of times and the procedure is routine for us along with some complications that can be experienced from time to time. Due to this we have a flat rate fee for the procedure, not done by the hour for the various Porsches. This includes a new clutch (trust me, you need one if the car has more than 40K miles) and RMS updates along with the IMSR procedures. We are working with competent, open minded Porsche shops throughout the world to get this technology into their hands so more engines can be saved. Believe it or not some Porsche Dealerships have installed these IMS bearings. The technology can be applied as a preventive, or as salvation for engines with impending IMS bearing failures or failures that have not taken the engine out of service completely. To reduce some confusion: The IMSR (retrofit) and IMSU (update) are entirely different procedures, applied in entirely different manners. The IMSR is applied to existing engines before a failure occurs or after a failure has began to occur WITH THE ENGINE ASSEMBLED and still IN THE CAR. This is the process that was overviewed in the link provided by the original poster in this thread. This is the technology that offers the most value to an enthusiast who is concerned with addressing the issue prior to becoming a statistic. The IMSU is a procedure that modifies the entire IMS for the fitment of more bearings, thus spreading the bearing load. This procedure must be applied during an engine update when the engine is completely disassembled and generally reconstructed with much higher performance components. The application of the IMSU requires full disassembly of the engine. When I carry out these procedures I make other strengthening enhancements to the IMS, one of which that locks the bank 4-6 drive sprocket onto the shaft so it can never slip again, resulting in MOF #17. MOF #17 is best illustrated by the pic I have attached, this occurred with an engine that had a perfectly fine IMS bearing that was misdiagnosed by a Porsche dealership as a bearing failure. In this instance the IMS failed.

i'm rethinking my strategery and doing the bearing replacement at my shop (Ottos) since my engine is out and the head is at the machine shop. I hope its now just the cost of bearing and a small labor cost because everything is apart anyway.

Jake, What is your flat rate fee for the IMSR procedure? Plus clutch and RMS udpates?

Due to Rennlist rules I can't discuss prices here. I simply wanted to make an informative post with the details of the two, how they were developed and how they've been applied.

If I was keeping my car I would definitely do the IMSR. Pretty cheap insurance IMO.

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Should this procedure be viewed as risk reduction or actually as insurance?

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You forgot "unnecessary" and "paranoid".

How about trying to avoid to keep paying for a leaky IMS seal? How many times would it take before you decide its time to do something about it other than just keep paying to have it fixed?

hold on - IMO with my car this is just a good idea.... since it CAN be done - I will do it at a convient time - I just changed out the front hub on my suburban and I can tell you that bearing went from good to really bad - really quick!! My motor has a lot of miles and if I go in to swap the clutch, this bearing is coming out and being replaced - end of it.... its not parinoid, its just a really good idea FOR MY KIND OF THINKING - I really dont care if no one else in the world changes thiers, I am changing mine I know you had like 3 RMS/IMS seals replaced, I dont know why....I dont know what you consider a leak.... for many... one drop is a leak, for others a few drops a month is OK...this is NOT that type of issue....if this thing goes its a BIG DEAL !! if a seal leaks a drop a week... add a drop of oil and wash the bottom of the motor <steps off box>

Well for me it's also a matter of peace of mind in addition to $$ sunk. An IMS seal is not supposed to leak and it can be a precursor to failure. I can fix the leaks as they occur since one that does not leak is less likely to fail or try to stop them from occurring in the future. As far as I can tell the IMSR offers the best hope for that. Not everyone is in my boat, I understand that. I just don't like being labeled paranoid about this. I can afford the $2K for this fix, but my wife would have my head if I presented her with a $15K engine replacement bill. So it's also about self preservation Either that or I sell and get a car that has the GT1 engine.

Lets just say that the majority of the IMSR procedures I have carried out have given us some of the best testimonials in the history of my company. Its fairly difficult (generally) to exceed the expectations of a discerning owner when applying a preventive procedure thats not cheap. These owners have driven or shipped their car from various parts of the country to have work done that doesn't give them any added performance... They never feel or see the difference the IMSR affords their engine. Amazingly, they are among the happiest group of people I have ever worked with after the fact.

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My point is, the fact that there is such a low statistical risk for a bearing failure, why would anyone waste their time and money, baring any evidence of impending failure, on such a mod? A few dozen or even a few hundred suspected bad bearings is hardly a risk people should be worried about. Fear is a big driver of many unnecessary mods. I suggest that people just enjoy their car and leave the fear in the garage. For those cars experiencing IMS problems, your mod sounds like a good choice.

The main problem lies in the fact that other than a slight bit of oil leakage and maybe a rattle 2 minutes before total failure, there are no symptoms of the IMS syndrome. One of my clients who is a Neurosurgeon described the failure of his engine as an "Aneurism" because he was driving fine one second, the next second the engine was dead. We have been able to save a number of engines that were caught early on with failures that had not yet scattered parts all over the interior of the engine. These are few and far between because when people hear noises they immediately try to limp the car home or to the shop to save a tow bill... That money they attempted to save costs a lot of them 15,000.00+ when the failure has it's grand finale. IF they would have stopped and shut the engine off we could have intervened and saved the engine before total catastrophe. I have a good candidate on the way now that was shut down just soon enough that we can hopefully save it.. The engine passed a leak down test with no bent valves and it seems that the oil sump, pre-filter and primary filter protected the engine from foreign object debris from the failure well. I appreciate being able to save engines that have failed more than doing preventives.. If only more people paid attention to their engines and weren't bullheaded about trying to "limp home" we'd be able to save many, many more. IF you hear a noise you must understand that IF that noise is emanating from the IMS that the life of your engine can be measured in seconds. I agree about enjoying the car- thats the only thing you can do if you choose not to elect for IMSR procedures as a preventive.. Enjoy it till the last second you can and don't let it worry you. Just pay attention. Attached is a pic of the engine thats heading our way for salvation. Its a rare case that didn't experience any secondary failures after the IMS bearing imploded. I'll have to cut this bearing race out with procedures that Porsche would cringe at, but I will save the engine.

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well, your point in theory sounds ok, in reality, when one's engine lets go just idling or tooling along, and THEN you discover you're faced with a $20K bill on a $35K car, I'd hope the 'expense' and 'fear' may be well worth it. To me, $1K sounds a WHOLE lot better than $20K.

The older cars are now "totalled" if they experience an engine failure because the engine cost more than the car is worth. The engine is too time consuming to assemble to ever complete corretcly for a lesser price than is currently offered. Trying to accomplish this cheaper simply creates more problems with corners being cut.

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I would never think that I could actually approach my auto insurance with such a claim. Although, frankly that's only because I've never heard of such a thing. In my case, at 90K miles, while I love the car, I would refuse to spend $20K salvaging it. It's just a car. I can easily move on with that kind of cost associated in keeping the thing alive. I will say that I guess I am "lucky" that mine was a valve sprint/valve instead of the bottom end, so that's enabling me to proactively chaning the IMS bearing and other stuff so I can get more enjoyment from the car.

So, is it safe to assume, to use Jake's analogy of an aneurysm, that the people who are unnecessarily getting their bearing replaced are also getting a full heart and artery scan on a regular basis and replace any, less than perfect portions with new graphs? I mean, there is a higher percentage of people in the US who have unruptured aneurysms than Porsche's that have a failing IMS? A lot of overkill and fear mongering is you ask me. But, millions have wasted money on ***** enlargement pills, too.

I am a bit concerned but do have some questions I hope someone can answer: Just to be clear, which engines are most susceptible to this failure? Is it just the 3.4L, or is the 3.6L also at risk? Are there versions of either that are more (or less) susceptible to this failure? Is this unique to the 996, or can other models have similar risks; 986, 996TT, GT3, etc. I understand that you really can't tell if an IMS is bad until its been removed from the engine-is that correct? If it is, I would like to ask Jake for some insight. Given that you have likley performed more of these procedures than anyone else, in your opinion what percentage of those that were replaced actually exhibited enough degredation to lead to failure? In your opinion, is this not an issue of "if" , but rather of "when" it will happen. Not trying to put you on the spot, just trying to get a better idea what the risks actually are. Based on what I've read thus far, I'm likely to have the IMSR completed, but I was never really able to find the answers to the questions above in anything I've read to-date. TIA

ALL M96 engines are at risk. I field calls from people with most every year and model of M96 equipped engines weekly.. **most** 3.6 engines have the weakest of all bearings installed, known as the "single row" bearing. The syndrome can occur with any year or any model. The engines manufactured post 2006 have an entirely different bearing that can't be serviced at all, because it can't be removed from the engine due to it's size. These are now starting to fail, but most are silenced by the warranty. The GT2, GT3 and Turbo use an entirely different engine. These engines still have an IMS, but it is the same as was found in the 964 aircooled engines. These have plain bearings, not roller bearings and they do not fail. Do not confuse ANY aspect of the standard M96 engine with any of the GT series engines- they share nothing in common. Boxsters and 996s both suffer the IMS syndrome. We field more calls from Boxster owners because there are more of them on the street. Yes, or until it fails completely. I know the sounds that they make when they are starting to go south. Last month I saved one that was going south and had started to spin inside the IMS tube. The only thing holding that one in place was the internal snap ring because the factory bearing was .0015 too small for the shaft! I stay away from percentages and absolute terms because none of those exist in a mechanical world where anything can happen for any reason at any given time. Lets just say this: Once the bearing begins to degrade it's internal clearances are effected. When this occurs its a fairly quick progression from "about to fail" to "failed". I have seen some engines die from materials that were ingested into other critical clearances that came from an IMS bearing that was heading south, but hadn't reached a level of total failure as of yet. Long story short, when the bearing begins to degrade it doesn't last long enough to be diagnosed most of the time... One instance was an Owner who heard a noise in his engine at start up that hadn't been there.. It was an Anniversary Edition with an X51 package. He stopped the car, drove another car and then came back later that day to see of the noise persisted; it did. He then called the Porsche Dealership and told them that he had "An IMS bearing starting to fail". They sent out a Technician (since they were slow) to pick the car up and instead of winching the car onto the roll back the tech cranked the car and drove it onto the truck. Bang, end of story- there goes 20 grand. The Owner did the right thing and he had read about sounds here on rennlist and other forums, the driver of the tow truck needed a good slap for starting the engine... No one knows what the risks are.. I am one of a very, very small group of people that have jumped into these issues outside the factory and I only see a small portion of the big picture. I will say that in two days I have received 5 emails from those with IMS bearing failures, thats more than I have received in the past week from people wanting to apply our technology as a preventive. You are less than 60 miles from me.. You should schedule a time to see these parts and how they work first hand. The majority of our clients are several states away, not able to take advantage of this. I am not trying to instill fear in anyone, merely stating the facts that I see on a near daily basis. If more people understand why these bearings fail and what the symptoms are the more engines we'll be able to save.

Yo Jakes, what does the impending IMS bearing failure noise sound like? Have any sound clips? Thanks, Robert

Let me restate a question that was posed earlier, and I'm not sure that was answered. Is the retrofit actually a solution? Or does it just reduce the chance that a failure will happen? Are you contracting with regional shops to do these installs?

The retrofit replaces the factory conventional roller bearing with a hybrid, silicon nitride ceramic bearing. This bearing technology was not available when the M96 engine was developed, it was still limited to aerospace applications and military weapons.. I have utilized silicon nitride components inside other Porsche engines with excellent results dating back to around 2000. The material is so hard and wear resistant that about the only thing that will cut or drill into it is a diamond tipped tool. Its a bearing thats basically as big and as strong as we can place inside the stock IMS without parent material removal. No stronger bearing could be made. I have started a program of training local shops from across the world to work with these engines and do our procedures. The primary goal by years end is to have that program in place with a step by step DVD to walk the DIY or professional mechanic through a successful bearing extraction, inspection and replacement. As far as the sound of the bearing, well that takes a trained ear... No sound clip could be made with enough clarity to represent the sound of an impending bearing failure and they always sound slightly different according to what mode of failure the bearing is experiencing.

Lurking on this thread. Hope this isn't rude, but I wanted to offer up one owner's experience to add to the discussion: Attached is a picture of my trouble free, leak free, 94,000km engine after we opened it up to install the LN retrofit kit. You can see the leak around the IMS seal starting to happen. Also, the shaft itself was filled with oil. I'm glad I did it. For me personally, I would have been glad even without the leakage. You may believe I'm an idiot for paying so much for insurance, and maybe I am. But when you hold the piece in your hand and look at what it's replacing, it really is reassuring.

Here's a youtube clip of an IMS dying--you can hear it come in a little after 1:00 while the engine still has power, but who knows if the engine was already toast at that point. Pretty low quality audio so the sound was probably noticeable sooner. http://www.youtube.com/watch?v=9BQ5XAIzNVA It's kind of painful to watch because you hear the sound come in and he keeps on going and you just know and oh god oh god why isn't he turning the engine off CLACK clunk clunk clunk clunk... ****.

SWEET!!! Thats ONE of the noises. Classic example. Thanks for the video.

Thanks for the video, I linked it on 986forum.

So, I take it from your answer that you hope it works. There's no guarantee. It may, in fact, not perform better than the factory original. Only time will tell.

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From your experience, what are the chances the engine could have been saved if he had shut down immediately upon hearing the noise? He still had power for a couple of turns so I'd imagine the engine would be save-able, right?

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We are keeping track of every IMSR bearing sold and serializing the units along with tracking VIN numbers.. Due to this we'll be able to prove the effectiveness of the bearing over time through the data base. It'll take years to prove that the bearing is THE absolute resolution to the problem. I am confident that it'll maintain a flawless record as I have prior experiences with silicon nitride bearings and other engine parts that have proven to be absolutely indestructible. We are keeping total track of the bearings that are being employed for a couple of reasons: 1- People are already selling cars that are advertised with the IMSR bearing that HAVE NOT been subjected to the retrofit. 2- So in a few years we'll be able to use the trend data of the component to answer questions from discerning owners just like you. I prove what we do and do a better job of that than anyone. Dave!, If that engine had been shut down immediately after the noise had been notable the chances of it's salvation would have been very good. At track speeds it doesn't take very long at all for the cam timing to retard just enough to kiss the exhaust valves into the pistons resulting in a secondary failure thats just as damaging as the primary failure. If you hear a noise that you haven't been hearing and if that noise sounds metallic shut the car down and have it diagnosed. Not many things in these engines can make a sound if they are "healthy"... About the only thing that can make a sound similar to this and be a "simple repair" would be a noisy water pump due to trashed bearings. If in doubt STOP!

Great, now I'm going to be shutting the car down every time some change rattles in the ash tray. Just kidding. Another question: I'm planning on dropping the transmission soon to replace a noisy bearing, so I was thinking about doing this retrofit at the same time. I wanted to do this as a DIY, but looking at LN Engineering it says Locking the cams and pulling the tensioners is beginning to sound like something I might not want to mess with, or might require fancier tools than I have. I just wanted to know if this is something you could recommend as a DIY (easier than it sounds) or if I should let a shop handle it at that point (Dave, please don't break your engine).

Raby, is the bearing made by *** in Germany. That is the brand our jet engines use. Just curious.

Jake: Have you trained anyone in California to do the IMSR retrofit?

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Bruce, Welcome back! Missed you. Did you send your car down from Toronto or did you have it done locally?

Hey, Chao, I had it done locally. It was the first in Canada to get the part for the double-row version (maybe the first, period, but I don't know that for sure). Charles Navarro from LN provided great support for my indie by phone. These guys have done more since mine, and I wouldn't hesitate to recommend them to anybody in my area for the work. Guys will probably think me a fool, but I'll probably get them to drop the engine again in the spring so we can eyeball the new seal. I personally believe that the 'value' of my car lies in its future enjoyment, not in what Autotrader says, so I don't mind spending the money.

Welcome back Bruce.

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Do you mind sharing how much you paid and how long it took them? labor charge per hour and how many hours it took them..

Thanks, Tippy. I couldn't resist this topic. Having done the upgrade, I wanted to contribute.

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My pricing won't make much sense to most guys here, because we seem to pay so much more for everything than you do. Let's just say that the labour was about the same as the labour for a clutch replacement. Whatever that costs where you are is going to be the ballpark price for the IMS bearing retrofit. FWIW, my rationale on some of the earlier questions was this: Every M96 engine is vulnerable because of the IMS design, and always will be regardless of what you do to 'fix' it. But the retrofit part is overbuilt to a degree that Porsche could never have afforded on a mass scale. I don't see it as eliminating the risk 100%, but I do see it as reducing it by many orders of magnitude, at roughly 10% of the cost of a new motor. Just speaking for me, that math made sense.

Bruce, So basically, if you are going in to replace a clutch, like a RMS replacement, it makes sense to do this? Obviously, the part is more expensive than a RMS seal...

Bruce -- also good to see you again on the site. Were you having other work done, so did this as part of a larger maintenance visit (e.g., doing a clutch, rms & bearing at once)? Or was this a specific, preemptive strike?

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IMHO, that would be an easy call. A large part of the labour is redundant. The incremental cost would be in the hundreds of dollars in that case.

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Thanks. This was a 'preemptive strike'. I love the car, and I've done a lot to it to make it 'mine'. There's nothing I want more that would even come close to justifying the loss if I sold it, and that includes a 997. So the game becomes one of how to make it last. As I said earlier, its value to me is measured in the miles ahead of it. So I'm a maintenance *****.

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Hi Bruce Who or where in TO did yours? How much? (I'm in Mississauga)

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These guys. I think it was in the mid-two grand range. I don't have the invoice in front of me, and I had some suspension work done at the same time. http://www.engineeredautomotive.com Dave Tomassetti is the former Pfaff tech I mentioned. I can't say enough good about these guys. Total perfectionists. They have a black C2 in there right now getting the kit installed, actually.

Thanks Bruce. Do you know if these are the only guys in the GTA doing the Jake Raby IMS bearing replacement?

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Sorry, I don't know. There certainly could be others by now.

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Quick question Jake: Have you worked with any Workshops in Australia that you rate to perform the upgrade? About to jump into my first Porker, want a 3.6 C2 6 speed, and plan on maximising enjoyment and minimising pain. As no amount of inspection short of a full takedown will guarantee I don't get something about to fail, and as half the cars I'm seeing haven't had their Porsche warranty maintained, I'd like a little extra peace of mind. Several of the independants here are imploring me to bypass the M96-engined cars and stick with a Turbo/GT3 because of these issues. Unfortunately I either lose practicality (GT3) and/or increase cost and age (both Turbo and GT3) Wayne.

Bump. Jake?

BWA Auto can do the retrofit kits and has experience rebuilding the M96 engine as well.

How about any shops in northern California? TIA.

Since many asked, the shop that did mine here in Southern California is Otto's in Venice. Daniel, the tech is great guy. I have had my car serviced between them and Callas Rennsport in Torrance, so i'm sure Tony can also do this; Otto's was simply closer and I've been going to them recently. Both are perfectly great shops.

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Jake has not been active on the forums since his dad passed away a few weeks ago http://forums.aircooledtechnology.co...cement.php?f=2 John

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That's so sad. Thanks for posting the news and letting us know, John.

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Yeah, I saw that when I went to his website. Bad news every which way you look at it. Charles' earlier answer helps me out for now anyway. My condolences Jake. W.

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Thanks Charles! That helps a lot, I'll give them a call. They are only a short 3 hour drive from where I live (a run I tend to make every week anyway), so that's excellent! :-D W.

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Charles: Who do you recommend in the NW Burbs? I missed the opportunity to talk to you at the recent Porsche club gathering a few weeks ago. Question: IMS - Are the issues for all M96 or just early years 99~?? that are subject to failure? Thx, 99C2

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The short answer is that all of them are vulnerable but the full story has been extensively documented here already a number of times. Search for Jake Raby's post on M96 failure modes. Good reading, if not a little anxiety inducing.

Currently, the only shop in the Chicagoland area that has done it is Joe Rizza Porsche, and they are very experienced with doing it. Another individual whom I met at the winter Tech session had Rizza do the work and they were very pleased with the price and level of service he received. Chris Schuh in Wisconsin also did one recently during an engine swap for our local region autocross chair who lost an engine to oil starvation at R.A.

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Van, what did you end up doing ? and are you going to Lime Rock this weekend ?

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I consider myself part of this group - my 3 year CPO had just ran out, and I decided it would be a good solution to something that potentially would keep me from sleeping well at night. I shipped my car from Rhode Island to GA, and it arrived back fine and I am not sure if the IMS would ever be an issue for my car, but at at least I took some action that should have positive results - both from a car standpoint and my paranoia level (and also the other stuff like clutch kit, water pump, and other stuff that needed some attention like a sticky lifter and the other common while you are in there stuff RMS etc.).

Ceramic bearings are that expensive. Porsches are very high profit margin cars. Porsche engineers neglected to provide adequate lubrication to the bearing and assumed that sealing the bearing would fix it. they were wrong. Porsche has designed out the IMS. IMO, that was the wrong direction.

Jake, I have a '99 that has dual row bearings. Why not neadle bearings for this application?

You need to read up on the subject. There is a history and reason for Porsches use of the sealed bearing there. There is no cooling via fresh supplied lubricant, so needle bearings would not last 100 miles. Plus there is rather large amount of needed axial play and loading, not suitable at all for needled bearings. The load, temperature, and lack of lubricant flow make the ceramic bearing the best choice.

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Lack of lubricant flow - LN Engineering uses open bearings that rely upon splash lubrication Temperature- use ceramic not high carbon steel Axial load- ball bearings can not support axial load, only thrust or tapered-roller bearings can be used. Axial misalignment- dual row ball bearings? eh? Tapered-roller bearings can handle some misalignment. Porsche's solution was to eliminate the IMS altogether instead of providing sufficient lubrication.

Only problem here is that you have no data on the quality,performance, or longevity for this kit, the LN unit has over 4,000 units installed in the field. I'm sure Casper knows their bearings, but I would be remiss if I did not note that LN and Jake Raby tested the Hell out of the LN unit before they made it available; I have seen no data on what level of testing this other supplier has done.... <link deleted>

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I just had my bearing replaced with the LN unit by Brent Hunter at a very reasonable price.

"I stay away from percentages and absolute terms because none of those exist in a mechanical world ..." just wow...

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Thats right.. To fully understand this you'd need to live a life where you manipulate mechanical things no less than 12 hours a day, everyday and even for fun. Anything thats mechanical can fail at any time, for absolutely no reason and it doesn't have to make sense... Nor does it have to ask permission. That comes from a person who has been known to hold engines WFO until they fail just to see what breaks first. The data to support any percentage/ statistical projections on the topic of the IMS failure simply does not exist. Three failure calls in two days are our statistics for this week and its only Tuesday.

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Just out of curiosity, what's the current failure count on the large/nonremovable M97 bearing on late 996/early 997 motors?

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One of the three failures I referenced earlier was from a late "big bearing" engine. 2008 with 23,000 miles for that one.. We are seeing more and more of the later big bearing failures. Like the older engines, it took us about 5 years to really see an influx of issues from the 06 and later engines. It seems the later engines have more issues with broken timing chains and cylinder failures than anything else. On the track the newer engines have significant rod bolt failure issues, thanks to the longer strokes and shorter rods the factory used that increase piston speeds and the rod bolts were not upgraded to meet the increases.. Makes no sense to me, longer stroke, shorter rod, more rod angle and faster pistons speeds, then you hang a bigger and heavier piston from it all.. Makes absolutely zero sense to anyone other than a bean counter.

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Jake, with the earlier engine failures it seems that it's largely (not all) due to low usage/low rev cars having the failures. Do you feel the later engines suffer from the same "abuse"?

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The earlier bearings were smaller and saw reduced surface speeds when being driven slowly.. The loads the bearing more and increases wear by reducing full film lubrication. The earlier bearings LOVE high speeds as the load is reduced and the bearing sees better lubrication. The later bearings are larger, which increases surface speeds at lower engine RPM levels. These bearings are doing better on the street, but worse on the track. What impacts both of these are extended oil service intervals and elevated total acid numbers in the oil which hardens and breaks down the seals that are fitted to the roller bearings, starting the Stage 1 bearing failure. The issue is the fact that a roller bearing should have never been used and it certainly had no place being sealed, or having an outer race rotation. I have a chapter in my book on this topic.

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Thanks Jake......couple of things.....1) when I said "later engines" I was refering to the '08 engines you mention......is that what you were referring to when you said "the later bearings are larger"? 2) You mention "roller bearings".....the IMS bearing that came out of my '03 is/was a ball bearing, not roller........where's my disconnect with what you said? 3) So, it seems that if you keep the revs up and change the oil at the proper interval, or earlier.......the world is a wonderful place? Best Regards Les.

All engines post 2006 have the larger M97 style bearings. These cannot be retrofitted as the bearings are larger than the access port in the case. A ball bearing is a type of roller bearing. Some have needles, some have *****, but both are roller bearings. Thats not magical.. It all boils down to how good your luck is.

Quotes source post: 9800495

Ok, never heard that but as lon as we know to what we're referringm that's fine. So the design is inherently flawed and it's just down to dumb luck whether or not your engine blows up? If so, why spend any $$ on these not inexpensive upgrades? Best Regards Les.