JMLavoie

JD: I believe if you look under your driver's door jamb, you will see a date of assembly.

996_North

I would also check your engine serial. Mine is an early 99 (built in 98, amber tail lights an indicator) but it had a replacement engine at some point in its history , and I had no record of that. I am guessing 2001 or later. Swapped out my IMSB and found it was a single row! If there is an AT in the serial it is a reman engine. I went from a high mileage 99 dual row attitude to a low mileage single row.

Flat6 Innovations

With any 2000 model vehicle its a total toss up as to if the engine will have a single, or dual row IMSB. The numbers have proven to be worthless, as they are constantly inaccurate. Porsche kept poor records on this aspect of the engines.

A visual inspection is the ONLY way to know which bearing is fitted.

Ahsai

Came across this article. Seems to have captured the main IMS options pretty well. They missed the relatively recent FVD ceramic sealed bearing option though.

http://www.thepopularmechanic.com/Po...MSOptions.html

Thumbie

^That is a very short and sweet article with good info.

Seems like oil-fed would be the way to go, especially the cylindrical bearing option.

That's the one thing no one seems to have an answer to is which solution is best, or if they all have worked as intended with no problems.

Coy Gillenwater

Has anybody used this before...

IMS Guardian

http://www.pelicanparts.com/catalog/...UPG996_pg1.htm

Flat6 Innovations

I developed the Guardian. It gives a symptom to an otherwise symptomless failure.

It doesn't keep wear from occurring or doesn't address the issue, it only tells that you have an issue pending. That's a big help, and saves the rest of the engine from collateral damage. If you have the funds to retrofit, then do that. If not, employ the IMSG.

clearwaterms

If somebody were buying a 996 that appeared problem free except no indication of an IMS retroit, would you recommend the guardian until the next clutch service?

Does a magnetic drain plug interfere with the guardian?

clearwaterms

Has the failure percentage been changed at any way in the 3.6L when compared to the 3.4L?

emtee49

After all the reading I've done regarding this IMS issue - there is one question I haven't seen an answer to: Why do 90% of the bearings hold up and 10% go bad? I've read the "garage queen" theory and the "track car" theory. I've also seen the "lubrication" theory. Is there a definitive answer out there or just a bunch of theories? . . . Now if I could just figure out if mine is one of the 90% ones or one of the 10% ones . . . before.

Jake Raby

But thats not all.... I haven't even started discussing the impacts of issues that exist between the distances of IMS housing bores in relationship to crankshaft centerlines.

This is a huge deal, and has been overlooked by everyone else. I have develooed a tool to measure this when doing retrofit procedures. if these distances are too great, or not great enough, the load that the IMSB sees from the chain, tensioner is greater.

emtee49

WOW! Now, THERE'S an insight, IMHO. I figure that there's got to be something different about the vehicles beyond usage, etc. How does this variance happen? (It kind of reminds me of way back in my Corvette days, when some of the 327 engines' cylinders suffered from "core shift" from the sand moving during the casting process of the block.) How much variance has been found? Is there any kind of pattern to it in terms of model year or manufacture date? Very interesting stuff.

5CHN3LL

Until every M96 has croaked, we won't know the ACTUAL percentage of failure due to IMS bearing. The true number will be higher than the figures stated as part of the IMSB settlement.

If the 10% number was accurate at the time when it was published, and it is true that (a) people are still experiencing this failure and (b) the number of 996's is constant (i.e. they're not making more of them), the 10% number is no longer reflective of reality.

My point is NOT that we're all gonna have IMS bearing failure. If I thought that was true, I would get rid of my 996. My only point is that the actual percentage of IMSB failures is unknown, and probably unknowable. Trying to identify an exact percentage is a fool's errand, and tossing numbers around and claiming they're exact percentages is deceptive.

Southern Man

Well I am at a point of decision. I have an '02 Carrera I bought two years ago with 100,000 miles (had just turned 100). When I bought it I was very concerned about RMS/IMS, etc., and either required documentation that they had either been replaced, or I was going to have it reflected in the price. I searched for 6 months to find the right car, and THOUGHT at the time that the IMS had been replaced at the local dealer, along with the clutch and RMS, just before I bought the car. I'm convinced the PO thought so too, because although not an expert he was aware of the matter. Now, two years and 44,000 miles later, I have accidentally discovered that the IMS was NOT replaced. I do not think the PO lied to me - I think he honestly didn't understand. (Service report stated the dealer replaced the Pilot bearing.)

Not being sure, I went to the dealership's service dept to find out. Not only were they able to confirm that they hadn't replaced it, they told me they had NEVER replaced an IMSB! I was shocked, but in hindsight I guess they wouldn't want to use aftermarket parts, or admit there is a problem, so that may be why.

Nonetheless, what do I do now? I'm tempted to do the LNE retrofit, but then I see stories of THOSE failing. Now I'm wondering, if I've made it to 144,000, do I mess with it at all? I check my filter every oil change, and change it every 5,000 miles or so. I don't have a magnetic plug, or the Guardian. At the very least I guess I should get one or the other. My local indy charges $1,800 to do the IMS, so it's not as onerous as some people have cited here. Still, that's money I'd rather spend elsewhere!

I LOVE this car and don't plan on selling it. It's been my DD for two years now, and getting into something else just isn't going to cut it. High miles don't bother me. I just fix stuff and keep on driving. Overall this has been a stellar car to own, and my costs have been relatively minimal. I'm tempted to just keep driving it.

Suggestions???

Flat6 Innovations

PM me the name of that dealership, I bet they have done a retrofit before. Only three dealers in all of North America haven't done at least one IMSR job the last I had checked. The last place I'd take a car for an IMSR is a dealer, they seldom pre- qualify and they charge more.

That said, an engine with 144K must be pre- qualified for an IMSR very closely to ensure that the owner will get a good return on the investment if the retrofit.