If you think IMS bearing failures are all myth, then check this out...
 

This is a car that I bought last year from a fellow who took it to a local Porsche shop here with some odd sounds when running. The car ran and drove, but every few seconds, it would create a loud screeching noise and other associated weird noises. I bought the car for $10K from this fellow, as it was headed to LA Porsche dismantlers if I didn't buy it. The car drove and appeared to run okay, but kept making these noises, particularly on startup. Sometimes it ran perfectly quiet, sometimes not.

The car is a 1999 Porsche 996 Carrera 3.4 engine with only 31,000 miles on it. Today, we took the IMS cover off of the engine to see what was underneath. Check out what we found:

http://forums.pelicanparts.com/uploa...1274427477.jpg

The entire bearing has been destroyed. The seal is nowhere in sight, and the race came out stuck to the bearing cover (which was scratched and damaged). Apparently the balls were just floating around inside and it was only a matter of minutes before before the motor lost timing and grenaded. You can often detect a problem like this by plugging in the PST-2 (or Durametric) computer into the car and then checking camshaft deviation.

This car will be saved, as I think we got to it in time. As mentioned previously, we have a new prototype intermediate shaft bearing replacement kit that we are working on, and we'll be installing it on this engine for testing. This will all be detailed in a very lengthy tech article that I'm working on right now.

Enjoy!

-Wayne

Nice save. 996 motor in a Boxster or is this a 911? (Not that it matters much, just curious.)

This particular car is a 1999 996 Cabriolet.

-Wayne

I certainly am convinced it's not a myth. The encouraging thing about your post here is that the bearing made some noise before it completely let go.
I've had my Boxster for less than two weeks and it seems to be perfect, but I keep cars a long time so I will most likely do the bearing retrofit before too long, just for peace of mind.

Kevin
2002 Boxster S

We have the new kit that will be coming out soon. In the meantime, there's the kit from LN Engineering that we sell as well..

-Wayne

$10k for a Carrera cab...nice deal, especially because the fix is simple when you know what to look for and how to go about it. That sucker was living on its last moments!

I'll be at Road America this weekend for a three day PCA DE (I'm a PCA coach/instructor); I'll report back if we have any cars with an IMS failure (we had one last year). We're more likely to lose a couple GT3's due to driver error...happens EVERY time.

Interesting - I am betting that most of the GT3 drivers are well healed enough to get them fixed and nothing is ever reported. Sounds like I better be careful if I look to buy one in a few years.

True, most are heavy on money and light on ability, from my perspective. Road America is a very challenging track and stresses both the vehicle and it's driver to the limits. It appears we have a fair number of Boxsters and Caymans from looking at the roster. Of course, there are quite a number of 996/997s participating that could suffer from IMS failures, as well; miraculously, the numbers are low. C Navarro will be there thrashing his Boxster...nothing like "real life" testing of your products!

Wayne:

For a DYI owner, do you think the 5k oil change interval with cutting open the oil filter as described in the latest Excellance article looking for evidence of bearing break up combined with a regular Durametric check for camshaft deviation (what's the code for that by the way) like monthly would minimize chances of the IMS bearing until it can be checked and replaced at a clutch change?

Sounds like from all I've read, IMS failure is an immediate event when it happens, but there are actually some warning signs as mentioned above.

I disagree slightly with what some people have said recently. Tony (Callas) and I have had many lunch discussions on the IMS. I can only go by personal experience. The car featured in the photo above clearly made some very troubling noises at startup and when running. Very loud, bad bearing sounding noises. Stuff that's bad enough that your wife would say "what's wrong with your car". So, at least with this particular engine, it was very clear that there was an issue with the engine. I think the engine rattling at startup is a big clue. My wife's Tiptronic car does that slightly too, but it also may be the chain tensioners filling up with pressure.

I'm also not sure if you'd see crap in the oil filter. I'll take apart the oil filter that I have on this 996 and take a closer look at it.

-Wayne

I believe it is an immediate event when it destructs, but the bearings go bad over a short period of time. Not sure there are enough warning signs for my comfort.

I just removed mine, from a 32,000 mile car. Bearing is very loose and wobbly, was definitely failing. No visible metal in last oil drain, and the area around the bearing was clean. Car made no strange noises.

I'll be pulling the pan and dissecting the filter, will post pics.

This kind of stuff makes me nervous! So i guess the idea is to be aware of this, watch for the clues and then if one get the chance replace it before it fails. What a drag.

Steve

I would definitely change it on low miles cars, and whenever doing a clutch.

I wonder why no one talks about inspecting them. When I pulled the cover, you could feel that the shaft was 'wobbly' and spinning the threaded shaft, it was not smooth.

I have good news folks. Last week we replaced the IMS bearing with our new Pelican kit and I have been successfully driving the car around for the past week with no problems. There was a lot of residue and debris in the bottom of the sump, and it looks like we managed to get almost all of it out. The engine is purring fine. We'll change the oil again tomorrow (third time in a week) to flush the entire system out, and then I will toss the car to my friend who commutes about 600 miles a week for "extended testing".

After we confirm no leaks, we will have the kit available for purchase!

-Wayne

very nice. Really interesting Wayne. Any first approach on the price for your kit ? What would it include ? What tools would be needed to change the bearing ?

Keep up the good work

have you started to sell the product yet?SmileWavy

Extensive testing
 

Heck with the kit.....wayne i would love it if you would just flip me a car for extensive testing. Great support you offer.

Just got our 2002BoxS back from shop, went in with seized alternator (nasty noises there) but while in the air decided to have them pull trans and just DO IT... you want piece of mind driving a car that
will lunch it's engine at 6-8k a pop. New rms , L&N ims bearing and clutch check....
Had 115k on the clock but I hate that ticking sound of disaster.

Actually, we *just* put back together the 996 with the prototype kit and we will be doing more testing next week. I anticipate that the kit will be "certified" and ready for sale probably in February.

Thanks!

-Wayne

Wayne: as soon as this kit hits the market it looks like I will be in the market for a 986 or 996 that needs a clutch :)

I wouldn't drive one unless I personally knew that it had a new IMS bearing.

I'm so excited!

Jackson

Keep watching here, I will announce when we have them in stock. So far, the kit has performed flawlessly, rescuing a doomed 996 - the owner was told by the dealer it would be a $15,000 engine replacement. $150 later, and the engine is purring like new! Even has a brand new FabSpeed exhaust that we just put on it yesterday!

-Wayne

I am interested in the kit too. I'd like to keep my '99 986 from self destructing but I have to be honest and say that the price to do the fix will be the determining factor. I'm not willing to put 25% of the value of the car into a fix on a motor that already has 80K miles - I'll just drive it until it explodes and then sell what's left and buy another very nice $10K 986. With used 986 prices so low, the cars have almost become disposable.

Wayne: Now that the holiday season is over I was going to pull the transaxle and clutch on our recently purchased 98 boxster with a 2.5 and confirm the IMS bearing before ordering a ceramic bearing and other parts. You mention that a new kit will be out in February. Should I wait? Can you tell us in advance what the changes are? I can wait as the car does not go back on the road til winter is over. Car has 42,000 kilometers. My 101 Boxster book should arrive before I return home. Thanks Ron

Hi 986ron,

The differences between the LN kit and our inexpensive kit are detailed here: Pelican Technical Article: Boxster Intermediate Shaft Bearing Replacement and Upgrade (IMS) - 986 Boxster (1997-04) - 987 Boxster (2005-06)

I expect the kit to be available in February, maybe in March if manufacturing takes longer than expected.

-Wayne

then I think I can get the bearing ready for next spring :D

So are the remanufactured engines Porsche replaced during the RMS issues safe from the IMS failure? I am guessing that all of the 986 (3.2L) remanufactured engines have this bearing type...

From Wayne's IMS Tech Article:
"This is a photo of the very late-style intermediate shaft cover. The most obvious characteristic of this design is the very large nut that fits on the center bolt. The bearing behind the intermediate shaft cover shown here is not removable (it's too big to get out of the bore in the case). These are installed on Porsche rebuilt motors, and later style M96/M97 motors. If you see this large nut, then simply leave it alone: you cannot remove the bearing without splitting the engine case."
http://www.pelicanparts.com/techarti...all/Pic017.jpg

No, decidedly not. We have seen a couple fail; others have also been reported on several websites. Jake Raby has also commented on this as well. The apparent reason for not hearing much about them is that they are just now coming off warranty, so it is becoming more evident.

Basically, if it has an IMS, it can fail, regardless of the version............

Nothing can be done to upgrade / guard against failures with the big bearing, as you cannot remove it from the case (it's too big for the hole).

-Wayne

Is "the big bearing" the one that is reportedly put in 2006+ cars? So even though it is supposed to be stronger, it still can't be upgraded? Is it truly stronger?

Not really, they still fail.

Actually, LN and Jake have been busy and developing a total shaft replacement that includes a redesigned bearing similar in construction to the ones they developed for the earlier engines. Replacing the shaft, however, does require "splitting the cases", so it is no trivial matter........

It sounds like what you're saying is the only way to get a reliable motor is to get a pre-'05 and have an updated bearing put in? Should the later models be avoided since you can't update the later motor bearings? (I mean '06 - direct injection models)

Given the choice, I'd go with an early 05 or older car in good shape and do the IMS upgrade. Reason I say "early 05" is that some of the late 05 cars had the last revision, unserviceable IMS; and you should be equally leery of any year car with a factory re-manufactured engine installed after late 05 for the same reason.

So what about the factory re-manufactured engines prior to 2005? Large bearing or serviceable smaller bearing?

Re-manufactured engines prior to '05 probably have Rev 2 and not the Rev 3 "split the case" IMS. But everyone has been surprised by the occasional variation and those who know say the only way to really really know is the pull the trans and have a look.

My "1999" 996 engine that was a factory rebuilt engine has the big non-removable bearing. I'm not sure when it was put together though. Probably around 2006 or 2007...

-Wayne

Engines rebuilt & installed prior to 05, they would have the serviceable unit, 05 is a transition year so it could go either way. Engines installed in 06 and on will be the problem child, regardless of the car's model year............

I think the jury is still out on the bigger bearing. Frequent oil changes seem to be the number one factor in protecting the engine from this type of problem.

-Wayne

Wayne,


Is the kit up for sale? I am adding a tpc supercharger to my car and want to do this to my car why its all apart. Let me know please ty

Before any type of new bearing is fitted, measure the housing and ensure there is a "interference fit" on the outer ring as specified for the bearing type. Zero interference will definitely cause premature failure. Is the sprocket a shrink fit on the shaft and then machined after/ or is all premachined and then pressed on??

2001 boxster owner