How Common is IMS/RMS failure???

Seems like I'm finding a ton of info warning about IMS/RMS failure and I was wondering if anyone really knew how common of an issue it is? It seems like everywhere you look on the web people are talking about it but then I've found Totall911.com articles which speculate its only about 5% of the cars made. Thoughts?

In the last 19 months I have seen 9 of them. One of them had the cam deviation chatter.

5%. Of 145,000 M96 996's... 7,250 failures. Ref. The Truth June issue GT Porsche.

IMS and RMS are two entirely different issues and they should not be discussed in the same context. IMS = Intermediate Shaft RMS = Rear Main Seal The RMS issue is a leaking seal, nothing more. It's actually quite rare to find a car with a leaking RMS these days - most leaking seals have been replaced with the latest version which doesn't leak. Those motors which could not be fixed because they were out of spec were replaced by Porsche under warranty. RMS issues are easy to spot and the issue is harmless, except maybe a spot of oil on the garage floor. The IMS though is a different story. (OK - IMS seal leaks can occur, but like the RMS these are harmless and easy to fix.) IMS *bearing* failures are a real problem. The bearing that supports the intermediate shaft was poorly designed and prone to failure. It gives little to no warning before it fails and when it does fail it destroys your motor. Dead, done - you're not rebuilding the old motor because it's fu^%ed. You're buying a new motor. This has been discussed to death on line, and then discussed a zillion times more. In the end though, the answer is always the same, only Porsche knows, and they probably don't even know, and at any rate they are *not* saying anything. Problem is that Porsche replaced a lot of engines in the first five years or so, all under warranty. Not all of them were IMS issues, some were RMS issues that could not be solved, some were for cracked heads, some were for porous castings, some were just service manager's taking the easy route to making a customer happy. Porsche took all of the motors back for analysis. most were re-manufactured with upgrades and these went back into the system. These days we rely on the experience of knowledgeable independent repair people, but they only see cars with problems so they have a biased view. After all the chatter is done, a figure of between 1% and 5% seems to be consensus, with the later 3.6 litre cars suffering less than the early 3.4 litre cars, and with early Boxsters being the worst....depending on who you talk to because of course there were a lot more Boxsters sold, so in absolute terms there will also be more failures. Now don't ask again because M96 owners get annoyed by the question.

I've got an impression that the failure rate is much higher. But you are right, independent repair people are like doctors, they only see sick patients. As a PS one of my customers with an 02 boxster bought a crate motor 2.5 years ago (35k) because of an IMS failure; this time I did an oil change and found the filter full of metal. And to add insult to injury, I checked PET about two weeks ago and the prices of the early engines doubled from 9k to 18k. This will really total a lot of the early cars as the cost of repair will be two to three times value of the car.

Quotes source post: 6224151

Keep in mind that on these forums you will only hear about the failures as no one posts "I've got ****K miles and no IMS failure!" The 986 forum is one of the worst, in my opinion, as there is a business that posts about them that stands to make money off the fear of IMS failure.

Jasper covered it in a nutshell. I've seriously considered a 996 - it's a lot of car for the money. Three hundred HP, rear engined goodness for 17-20K! But, all you need is for the engine to conk on you and you're instantly upside down - on a car that still depreciating. I'm still tempted...

To what extent is IMS failure a concern on the 997.1? Just bought a 2006 with a M97.01 motor and wasn't aware of this issue until now.

Check out "total911.com" and scroll down to "997 engine failure: fact or myth" 1999 thru 2008 models are mentioned

Well that was a long and depressing read. I just have to hope that I'm not one of the "unlucky" ones.

I would drive the piss out of it and not stress over it. If it's gonna fail - it'll fail no matter what you do.

Honestly said : the 996 is a great car. IMS can be replaced it's not alien tech or un obtanium. The RMS if it does go, does suck but it all depends on why. Most 911's of any vintage that have problems tend to be heaps due to deferred maintenance. Sure like all things mechanical they have soft spots. But if you want a nice machine not über Spartan the 996 in my opinion is what I call the 911 for everyone. Where I'd say on earlier machines you need to be a special breed for such cars. The 996's are a lot of fun, comfortable too. Like anything take your time and go thru a number of cars vs the first thing that comes a long, records are nice but not always indicators of a well kept machine.

When you buy, budget $1000 to have the LN IMSB installed. Intermediate Shaft IMS Upgrade and Retrofit Kit for Porsche 911, Boxster, and Cayman models

I recently lost my clutch in my 2000 986 with 60,000 miles. Upon inspection, Porsche reported that I also had an IMS & a RMS leak, that needed to be addressed immediately. Total cost for all three issues.....$2400.00 It's not purchasing these amazing vehicles, it's the price of maintenance. While they may be some of the most reliable vehicles on the road, when they need service, they are not cheap to repair.

Quotes source post: 6767677

This is why preventative maintenance is critical. If your cost includes a new IMS bearing you are doing fine.

Quotes source post: 6767873

+1 $2,400 for parts & labor on IMS, RMS and Clutch sounds like a deal.. 944 clutches alone (P&L) can cost nearly that when not DIY. Also, $2,400 is like what 4 car payments.. ? Worth it for such a fine ride.

$2400 is not a lot of money for a clutch replacement no matter what you drive. FWIW I just installed a clutch, flywheel, RS motor mounts, air oil seperator and clutch slave in my car. Parts cost me $2600, but I used a sport clutch which costs more. If I would have done the bare minimum OEM clutch and new RMW plus a IMS flange (no new bearing no flywheel no AOS no clutch slave) it would have cost $800 in parts. $650 for the clutch kit, 150 for the seals.

I've been looking at 996s And noticed if I used the search refine ( milage highest >) I found a bunch of Cars with 100 k plus and no Replaced engines

Quotes source post: 6772721

Well, not every owner knows whether his car has had a new engine installed though, and even some of the guys who know might not advertise it as a positive. There was even a guy here (or maybe it was rennlist) who aked if heshould avoid a car *because* it had a new motor. The absence of an advertised new motor doesn't mean much. The presence of an advertised ne motor does.

Higher mileage care have less of a chance of a failure. Change oil every 5K miles on daily drivers or every 6 months on a garage queen. Keep the oil level to the top of the stick. The numbers I read said "10% of the 996 engine failures were IMS related" not 5 to 10% of all 996's. I read somewhere that alot of the actual IMS failures had one thing in common, poor maintenance, low oil levels and filthy oil. My opinion, take care of your car, don't drive it like you stole it, after all you didn't steal it and if it granades its on your dime and keep an eye on the dip stick. If the IMS bearing lost its inner seal and the ball bearings are exposed inside the engine it is crucial that the oil level is not low so the bearing get lubricated by the motor oil. My 996 could pass for showroom brand new, I'd rate it a 9.9 out of 10 and it has 70+K miles. I drive it daily and only use Mobile 1 0w40. The car runs it's coolest with that grade, I've tried 5W40, 10W40 and 15W50, the temp gauge is cooking hot unless its 0W40.

After a IMS failure (I also had the RMS replaced), I was fraught with panic over having to replace the engine. A new crated engine from Porsche is now $20k ('03 986), and a rebuild was running about $7k or more, and hard to find to say the least. I asked my local mechanic where the car was to pull the engine to ship it to a rebuilder, as I was convinced I'd just bite the bullet. After a little more thought, we decided to simply pull the head off and see what damage there was. Lo and behold -- six bent valves on one bank of the engine (subsequently, there are a few more bent stems, so we're replacing twelve valves), and obviously the bearing of the IMS being done. I had thought, from the reading I had done on various boards that the engine was seriously gone -- I imagined bent connecting rods, cracked pistons, busted heads, scarred cylinders from metal fragments. That was anything but the case. It's not going to be cheap to repair the engine, but owning a Porsche isn't really cheap in any case. But on the other hand, we're a long way away from a blown engine where the block and pistons aren't usable. The chains were not in good shape, so they're being replaced. That much being said, the engine did shut down, and it happened at relatively low revs (if I recall correctly, it was essentially at idle). I guess it could be a lot worse if the engine was at redline and everything came to a grinding halt at high speed. But, at the end of the day, before writing the engine off, a good mechanic can see what the true extent of damage is -- and it may not be as bad as you may think.

Keep us posted as to how it all turns out...

I just could not sleep well knowing that my 2000 Carrera with 39,000 miles on her could just become worthless at any moment, so I pulled the trigger and hired a local European Auto place to do the work. In addition they would replace the RMS and check the clutch. Of course the clutch was 99% spent, so the clutch was also replaced. I asked for the original bearing back, see attached photos of bill and bearing. For all that was done, I don't think the drive out price is too bad. But I have to sell my wife on it......

By looking at the seal you did the right thing Dave

When I showed my wife the bearing, she asked, "You mean the bearing was good and you spent all that money to replace it!?" She just did not get it. BTW, the bearing had "JAPAN" stamped on the rubber seal.

10% failure rate....5% failure rate...etc etc.....like herpes, it's just a statistic until it happens to YOU. If I end up buying anything with an M96 motor, the first order of business will be to replace the *&%$@#! IMS bearing.

Quotes source post: 6231393

Your 2006 997.1 has larger bearing that is NOT replaceable without splitting the engine case. The LN bearing kit is not for you. The path forward is to maintain your car properly and actually follow what LN suggest in their write-ups. I have not come across a single bad advice from LN yet. So, use good QUALITY oil (see LN), change it often (8,000km or 5,000 mi), inspect your oil filter element and the canister as well for metal or plastic debris. Properly warm up your car and cool it down and don’t drive short distances. And more importantly, worry about D-chunks and scored cylinder walls instead of IMS. Read: Hartech.org buyers guide #5 if in doubt, which will shift your focus on maintaining your cooling system too. Best I can offer at the moment. Edit: AND ENJOY YOUR CAR, DRIVE IT, LOVE IT. I DO!!! Cheers, =L=

The IMS Guardian also for peace of mind and immediate intervention to prevent catastrophic engine damage. I got it. So, now I can worry about other stuff.

The M96 issues were thoroughly discussed in a famous Excellence article penned by Jim Pasha several years a ago. The various items that had been noted in the previous decade were discussed in detail, with much input and quotes from known experts such as Jake Raby. In addition to the known issues, it was also pointed out that the engines also have some great design features too. Of all the issues, IMS is one of the only one that remains a mystery (the question of cylinder ovality in 3.4s as documented by Hartech being the other). Porous blocks and slipped sleeves are both issues pertaining to a very specific number of early cars and RMS has been dealt with quite effectively. Six or seven years ago, the forums were ablaze with the "dreaded" RMS, but now, not nearly so much. The trouble with IMS is that there remains much mystery as to why some cars never have an issue and others do. Driving style, mainentenance etc. have all been hypothesized, but there is no clear cause and effect. Other than noting that good maintenance will never be a bad thing, where does that leave us? In my view, where possible (i.e. early 2005 and earlier), I would treat the IMS bearing as a wear item and periodically replace it (like water pumps etc). As well, I wouild replace it with the LN Engineering bearing, as that is an upgrade. I just bought a 2004 Boxster S, and that is my plan. Going forward, I plan to regularly continue to replace the IMSB with the LN unit, perhaps on a three year/12,000 mile basis. Most would argue that this is an excessively short frequency, but that is my conservative choice. As pointed out, clutch, RMS and other things can be attended to at the same time and, done at a shop, it should be less than $3K easily, parts and labor. That is not cheap, but ammortized on an annual basis, not so bad IMO. I truly beleive that if the IMS is dealt with in this way, that the rest of the M96 may be a great motor (cylinder ovalilty being the one other area I'd think about -especially for 3.4s). Obviously Porsche revised the IMSB design several times, and ultimately eliminated it with the 2009 9A1 motor. The question is a little trickier if you have a late 2005 through to 2008 M97 motor, as for those, the IMSB can only be replaced after the case is split, which moves it from something that can be addressed as PM within reasonable cost to something much more expensive. However, those cars have the latest IMSB design, and although the numbers aren't there to know for sure, I expect those cars are least likely to suffer. If I had an M97, I would maintain it very well (of course) and perhaps consider an IMS Guardian as an warning device. This is all written from a cautious, conservative point of view. Many people drive their M96s with no problems and never know what IMS is. I personally know of two Boxsters with over 200K miles (one with over 250K), none of which have had any major work. Howver, there are some (1%, 5%, whatever) who have the bad luck, and then it can be very expensive.

500_19B, well said!

Quotes source post: 6931798

After cleaning up the oil left on the bearing seal, it looked good as new.

You need to pop the seals off then clean and inspect the bearing, otherwise you are just looking at the outside of a box. All the action is on the inside. PS IMHO most of the IMS issue is the quality of the bearing itself. I have read some were made in Brazil, mine was made in Poland and now yours was made in Japan (lucky, probably the best). Global low cost outsourcing has not been good at all for bearing quality.

Did the 996 Twin Turbo have problems with the IMS Bearing? I am pondering an early 2000's with 50-75k miles on it for my next car to go with my 1986 930 slant nose. I thinking a tiptronic so that the wife has a toy car as well.

Quotes source post: 6949589

No IMS on a 996 TT since it uses an air cooled 964 type crank case.

Paranoid about my 1999 Carrera 4 IMS. I am going to do the LN. for a 5 to 7% fail is too high for me. My 63k engine runs great without problems. So while they are in there, what would be the smart upgrades and replacements that would save me money? My rear shocks are not leaking but the car hits hard over even minor bumps. Bilsteing, Koni or originals? What do you think of putting in a colder thermostat? I am told they prolong engine life. Also, I have a motorcycle and truly believe in the power or Neodynium magnets to arrest steel before it can get to the filter even. I have three for my 911. I want to put one near my IMS, but cannot figure where would be the best location. The other locations are open for your recommendations. These magnets have 130 pounds of magnetic attraction each. When stacked, over 200 pounds of attraction force. Together they cost me 65 dollars delivered. I recommend highly. Thanks Franks

Quotes source post: 6978851

I came millimeters from purchasing a 99 Carrera until I Googled "reliability".

Someone had mentioned earlier about the higher mile cars (60k or more) & the 02' & up are Less Likely to have either of these issues than say if you have a 99'-01' with say 40k miles. Would you say there's any truth to this.

Quotes source post: 6986208

What little truth there is to this is strictly anecdotal....but it's probably more true than not. I do know that there are claims that not a single M97 motor (ie motors built after mid-2005 some of which found there way into 996 like mine under warranty) has ever failed because of a IMS bearing, and that so far no-one has been able to refute this claim. I like those odds.

jwetering, maybe I was just Hoping it was True! I have an 02' with 60k miles! Lol! I've had it about 6 yrs. & never had ANY problems, no drips, no leaks. It seems like sometimes guys make so much more out of it than it really is & some worry their self sick over it, BUT then they're some that actually have a Reason to! jmo

Quotes source post: 6986278

Sorry, but that is pure fantasy; we have seen more than one fail, and are directly aware of others that have also died. If the M96/97 engine has an intermedate shaft, the rear bearings can and do fail, regardless of the model year...........

Over on Rennlist there are a few 997 owners who have experienced IMS bearing failures, unfortunately. The numbers do seem to be less than the M96 engines however.

Great discussion about this subject and very informative. As a result of the IMS and RMS issues, that's why I bought a 996 Twin Turbo. Two Turbos and 100+ more horsepower had nothing to do with my decision. Grin. Besides, I have a ton of other "issues" that keep me awake at night with the Turbo.

"In my view, where possible (i.e. early 2005 and earlier), I would treat the IMS bearing as a wear item and periodically replace it (like water pumps etc). As well, I wouild replace it with the LN Engineering bearing, as that is an upgrade. I just bought a 2004 Boxster S, and that is my plan. Going forward, I plan to regularly continue to replace the IMSB with the LN unit, perhaps on a three year/12,000 mile basis. Most would argue that this is an excessively short frequency, but that is my conservative choice. As pointed out, clutch, RMS and other things can be attended to at the same time and, done at a shop, it should be less than $3K easily, parts and labor. That is not cheap, but ammortized on an annual basis, not so bad IMO. I truly beleive that if the IMS is dealt with in this way, that the rest of the M96 may be a great motor (cylinder ovalilty being the one other area I'd think about -especially for 3.4s). Obviously Porsche revised the IMSB design several times, and ultimately eliminated it with the 2009 9A1 motor." From RennList: Originally Posted by Flat6 Innovations View Post I didn't avoid the question concerning bearing life.. The dual row units are good forever, single rows not so much because the bearing is 1/2 the size of the dual row. My response Originally Posted by DB's996 View Post I just had the LN dual row bearing installed on my 2000 996. From your statement, I assume that I am good for life on my old beauty? Jake Raby Flat6 Innovations: We can safely say thats one less thing you have to worry about. Now, go change that damn water pump. So I take this to mean that the dual row LN IMS Retrofit is good for life!

Jake Raby is going to be coming out with the IMS bearing "Solution" sometime next year. It is supposed to be a complete redesign of the bearing and will take care if the problem once and for all (unlike the retrofit which is recommended to be replaced on a periodic basis). He says it will be olutlined in an upcoming Excellence article.

I've been looking at 996s fav link: business english

My local Porsche mechanic is a friend of mine and a noted expert in my part of the state. His opinion is that the 996/997 has been the most reliable of any modern high performance car. He works on them all. (Audi , BMW and MB has been troublesome for awhile). He states the IMS is a very over discussed problem. He has done a few IMS fixes as per the customers request but out of 100s of cars, he has never seen one fail yet. Every oil change the filters are cut and examined.

Quotes source post: 9176214

Porsche's own data, released during the class action lawsuit over the IMS failures, place the failure rates on single row bearings at 8-10%, and the dual rows at 1-2%. So they do fail, and fail catastrophically.

Quotes source post: 9176957

I know, but I wanted to give a real world example of a very popular and busy indy Porsche shops experience with what they have actually seen through their doors.

Quotes source post: 9179509

Well, we are a shop that specializes in Porsches, and we have seen more than our share of beautiful condition cars literally reduced to rollers, and their owners often reduced to tears over something that is not supposed to happen very often. We have even had one owner suffer IMS failure twice on two different cars. The problem is real , and totally devastating when it happens. And, unfortunately, that is the real world..........

It indeed happens often on 996. That's why we can find so many discussions and posts talking about ims failure on the web. I found this ims bearing solution online. That might be useful.

Quotes source post: 9176214

Agree with you on that, I do believe there was an excessive amount of fear mongering with the IMS, perhaps partly to bring the price down for some who collect them,? I also heard once that the rare ones that do fail was due to (gentle driving) or storing for long periods then driving, ie' not driving as they were intended, dont know if this is true or not and the first ones built were the best, 1998c2 apparently they have double row bearings or something , im sure the questions will be answered in this thread.

In the latest Excellence magazine, the most recent update on the Porsche class action suit places the known failure rate at over 12% for single row cars (some 2000, some 2001, all 2002-2006). There is all kinds of unsupported speculation on the "why's and wherefores'" of why they fail, but the point is that they do fail, and in large numbers. And for every "why" example, there are glaring exceptions; we have a customer who religiously beats the loving Hell out of his cars, lots of track time, lots of aggressive street driving. He has suffered two failures in two different cars. Point is, this is not a miniscule issue that can never happen. And no version of the IMS bearing was immune, dual rows fail, single rows fail, and even the last design oversized units failed; which is why Porsche designed the IMS out of the later 9A1 engines. So the problem is real; and corrective solutions are available. You can choose to ignore, or take action and prevent it. It all hinges on your level of risk tolerance.

Hi Folks I was able to take a peek at my IMS bearing thru the small opening at the bottom of the case. Pic attached. Q? from the pic, can it be determined if it was replaced ? I have docs on this motor being rebuilt by a respectable indy - Guy Ober - San Luis Obisbo , and the repair was extensive @ 70k miles / w Triptronic . But I do not clearly see where the IMS was denoted. Head gaskets, timing chains, valve, etc, etc $8.5k Does the marking determine, original or upgrade , single row, dual row. Looks dirty, but no signs of leakage Thanks for the feedback. Mark

The only thing discernible from that photo is that whomever last worked on it did not know what they were doing as the IMS flange has sealant squeezing out around it. You should never use sealant on an IMS flange.............

Just my 2 cents. I have a 03 C4S and evaluated various solutions like LM IMS, Pedro's DOS and OEM IMS replacement but went with EPS IMS Eternal Fix with DOS for various reasons. 1. It made sense to me to flow clean oil through it to help it cool and keep this lubricated as well as distributed load on larger surface area. 2. I do change my oil quite frequently (4-5000 mi) and have a magnetic plug to inspect things often. 3. Cost - by quite a bit, the EPS solution is among the most affordable, specially if you DIY 4. Easily removable and "inspectable" during clutch replacement as it comes apart and not sealed like OEM or LN solution. https://www.amazon.com/Porsche-Intermediate-Permanent-Retrofit-Pressurized/dp/B00H8XH9ZQ/ref=sr_1_fkmr0_1?ie=UTF8&qid=1481379385&sr=8-1-fkmr0&keywords=EPS+IMS+fix Definitely sleep lot better now. 80K miles and enjoying every minute of it. Nothing against the other solutions, specially LN which have use their Nickies and IMS upgrade on a 99 Boxster. Sold the car a few years back to a friend but now has 80K on the rebuild and no problems. Good luck!

Quotes source post: 9352100

We do many of these and have had a few come backs for leaks at the flange. Perhaps the bore is starting to oval or it's our extreme temperature swings. I've noticed that some techs are starting to use some Loctite 5900 on outer flange seal which has not caused any issue yet.

So it sounds like one should have the bore checked before attempting to replace the IMSB? I'm hunting for a 996 and need to know all I can before pulling the trigger...

Yes, there is a go- no go gauge for checking if shaft is centered. I do remember one that had some shallow marks that you could just feel. Not sure how that could happen with a careful install. The gauge wouldn't have caught it.

Quotes source post: 9392074

We also do a lot of these, and have never had to use any type of sealant on the flanges. We have seen several where sealant was used and they subsequently leaked, which completely stopped leaking after the sealant was removed. Much like the PTFE RMS seal, these flanges to not like sealant. I have also not seen a tool measure the IMS opening concentricity; we do however have one of the factory "go/no go" concentricity tools for the RMS opening in the cases.

I would not use sealant myself but others here have. We also have the RMS cocentricity tool. Someone here made a tool for checking IMS shaft bore but I'm not sure it is accurate and don't use it myself.

Quotes source post: 9241329

JFP, is the Excellence magazine your source on the IMS class action suit? I just got a 2008 Boxster RS 60 Spyder with the last M97 iteration and although people say it can affect my car, I couldn't find a single person on the internet who actually had the issue with this model year. Tks Daniel

Quotes source post: 9434252

Not completely, the legal action fall out has been written up in multiple places, both online and in print. And we have seen IMS failures in late M97 equipped cars, but not at the levels of the 01-05 cars. Unlike the earlier cars, the M97's seem to fail more often in cars that are run hard, such as heavy track usage. Your basic rule of thumb should be if it has an IMS bearing, it is at some risk of failure.

Quotes source post: 9434264

Hi JFP, That is NEW news to me. I thought they all benefitted from frequent oil changes AND higher revs. My '06 high mile Cayman S has not seen track duty before I bought it. I give it 8 - 10 track days a year. I have the baffle kit in and am diligent on oil levels and changing it. This has me a tad worried now, but not enough to stop going to the track. Might short shift now instead of getting full torque in the rev range. Any other tips? Thanks, Tony

Quotes source post: 9435778

Jake had a post over on RennList indicating that he had also seen 5 failures, all track rats if memory serves.