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!

 

Isn´t the other way around? lower on M96´s?

 

I'm confused. If you have the larger one, what's the concern?

 

Miles on odometer?
Having trouble with it currently?

 

40,000 mile on the odometer. I wanted to perform the retrofit due to very minor metal shavings on my oil filter, as well as a peace of mind. IMS is much more common in the M96, I am curious as to see if anyone has seen/heard of an IMS failure in a M97.

 

C2 and not C2S? What is the build date on the car?

I am a little suprised as I have called LN before when looking at 2005s and the feedback I received is that they rarely have seen any 2005 C2 models that had the larger bearing from the factory.

The C2S model switchover was likely sometime around Feb/March 2005 on the build date (the black sticker in your driver's door jamb).


If they can't do the IMS and they are already in there you could replace the RMS to the newest seal to prevent future leaks, do the clutch and have the shop remove the seal on the IMS bearing for future splash lubrication.

 

The build date on the car is Jan/05. It is a 3.6, not a 3.8. I was also told by Flitworks although it is very rare, some early production 05's received the updated bearing. I will have them replace the RMS, and thanks for the tip on the seal. My clutch is still over 50%, so I am planning on leaving it alone.

 

Boy that is clear as mud now.

Some early 05 models have the larger bearings? (Mine is an 05 with 50k miles that I'm on the fence to replacing the bearing.) I was under the impression that the engine number prior to 05 69507475 all had smaller bearings? Is there another piece of information/data that could indicate who got the larger bearings?

 

My engine number is well before 05 69507475, therefore I went in fairly certain it had the small replaceable bearings. I was warned by Flintworks and LN Engineering, although rare, they have seen early 05's with the upgraded bearing. I ran the vin and engine number through my dealer, they were not able to determine if I has the updated bearing. The general consensus is most early production 997's have the small replaceable bearing, the only way to know for sure is to remove the tranny and determine it visually. This topic is also on rennlist, and through other's suggestion, i vrified with my build sheet that the motor is original to the car, and had never be replaced.

 

I went though another discussion dedicated to the IMS topic (http://forums.rennlist.com/rennforum...lure-mode.html) and it seems like a few 05 997 c2 owners have the same updated m97 engines as well.

 

Here is another that further expands on the topic
http://forums.rennlist.com/rennforum...s-bearing.html

 

Just trying reduce some confusion -- The 997.1 3.6L engines with the larger IMS bearing were still the "M96". The 997.1 3.8L engine was designated the M97 .

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Now im confused. I am under the impression that 3.6 engines with the larger IMS bearing are M97 engines. My indy told me I had the m97 motor with the larger bearing.

http://forums.rennlist.com/rennforum...ng-please.html If you read JM993's post, it sounds like M97's came in different displacements.

 

As they say, you can't believe everything that you read on the internet.

All 3.6L engines in the 997.1 from 2005 thru 2008 were the M96.05. Attached is the official list of all Porsche engines from 1952-2012 (see page 9).

https://dl.dropbox.com/u/93289189/Po..._1952-2012.pdf

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So is a 2006 997.1 safe? Now im holding my nards dam freakin rms b/s