IMS replacement dilemma
 

I sent my 05 997 c2 off on Tues to get the IMS bearing retrofit done. I just got off the phone with my indie that my car has the revised m97 motor with the larger dual role IMS bearing, which is non serviceable without a tear down of the engine. I am impression the failure rate is significantly lower in m97's than m96's. I appreciate your guy's inputs!

I don't pretend to be an expert in this area as I am a new owner but if it offers you any reassurance, before I bought my early 2005 997 I interviewed mechanics at two different indy shops (one which has been in business for 30 years) and the service manager at the local dealer, they all concurred that they had never seen a 997 IMS failure, only a couple of early 996’s with the 3.4 motor. I was able to purchase a 4 year full warranty from the dealer, but aside from that I am convinced that the chance of a true 997 IMS failure is very small, perhaps non existent in the revised (late) 2005 motor. Personally, I would not let worry over this issue rob you of your joy of ownership. I know there is talk of the IMS failure on forums etc, but there is no way to authenticate the reports or to evaluate the veracity or motivation of those reporting failures. I would put it out of your mind and enjoy your car.

From what I researched and heard from my dealership and mechanic is that IMS failure are seen in the m96 motors, which include some early build 997's. I have not seen any documentation of the new and revised m97 motor fail due to a IMS failure. Because my 997 is an early 05 build, I assumed that it had the m96 motor. So I guess it should be good news that I have the new m97 motor, if not for the fact I already spend the labor getting the tranny off, only to find out I can not perform the IMS retrofit and my clutch is still more than 50%:grr:

Why would you have not determined if it was an M96 or an M97 engine before you pulled it?? I'm pretty speechless!!

Lower, yes, is it due to a stronger bearing &/or newer vehicles probably, but as the vehicles age we will see more failures. Best to change oil & filter every 5,000 miles & inspect oil filter for metal particles. Consider installing the IMS Guardian. For more info see lnengineering.com

Porsche typically updated the IMS bearing during the last 2005 production cycle. According to my engine number, I should have been in the m96 engine number range. Since the original owner took delivery on Feb of 2005, I we determined the engine is indeed m96 due to the early production. Although rare, a few early production 997's received the m97 motor instead of m96. I guess I am one of the luck few...

Typically, it is impossible to determine if you have the updated bearing unless you visually inspect it after the tranny in removed. Much like the updated Mp3 compatible PCM, Porsche was not very consistant with their new parts during the early 997 production cycle.

I did the IMS upgrade on my '02, even though I didn't have any metal particles in my oil - just wanted peace of mind since I did a few DEs each year.

I wouldn't worry about it on your M97 and wouldn't do it - just 'over maintain' it with earlier oil changes and buy the IMS Guardian product if you have any outsized concerns.

I believe you can determine which motor you have by the first three letters in the serial number on the bottom of the motor. M96 / M97

By the time you pay for the motor tear down you might as well trade it in and buy a new 911. 2009+

I don't agree you should be able to tell by the VIN, build date and engine serial number.

Production date then.

Im sorry you disagree. But those are the facts I am told from Flintworks in Campbell, whom specializes in IMS replacement in the bay area; Sharkwerks, 9Elf Motorsports, and Sonnen Porsche in San Rafel. Sonnen ran my vin and engine code and was unable to be certain is my IMS bear was updated.

this 997 was a 01/05 build, in other words, early production 997.

Is it possible the car had an m96 engine originally that failed and was replaced with the newer m97 before you purchased it?

-Chris

there is a slim chance, although unlikely because any work done would've been cover under warranty and documented. I went though another discussion dedicated to the IMS topic (https://rennlist.com/forums/997-foru...lure-mode.html) and it seems like a few 05 997 c2 owners have the same updated m97 engines as well.

If you have or can get the build sheet (I guess that's what it's called - printout from Porsche's systems that shows the original options installed, order history/timeline, etc.) on the car, it should have the original engine number on it. The build sheet on my car does. Then you could compare to the current engine number.

Either way, at least you have the revised engine! :)

-Chris