DrBrain

Recently I bought an 2004 C2 cab. It had a IMB caused engine failure which was fixed by the local Porsche dealer in 2012. My questions as a non-insider:
Is there a chance that Porsche put in an "upgraded" IMB to replace the failed one?
What is the chance that the new IMB breaks and would the LN upgrade be advisable at this point?

Dennis C

Did it require a new engine? That's the typical fix for an IMSB failure. It's most likely a single-row IMSB in the new engine, and not really upgraded. The LN Engineering IMSB would probably give you a little more peace of mind.

DrBrain

No new engine but 8 pages long list of parts replaced. Failure happened when starting the engine at low rpms.

Ahsai

Checked the part list for a new IMSB?

PelicanParts.com

How many miles were on your C2 in 2012 when the failure occurred?
Mark/Pelican Parts

DrBrain

Yes, a new imsb is on the list. The car had approx. 44k miles on it.

alpine003

What does this exactly mean? I thought all engines started out from 0 rpms?

fpb111

How many miles now? IOW how far since the repair?
All M96 engines have an IMS bearing. Therefore all can have an IMSB failure, new , old, dual-single row, larger dia, LN, Casper labs, Pelican, etc...
Drive it enjoy it Change the oil every 5k miles.

KrazyK

That is odd. Maybe we're all starting ours wrong? This would explain everything!

soverystout

DrBrain,

You are getting all of these questions due to the understanding that if an IMS bearing went bad, regardless of any catostrophic damage to the rest of the engine, the dealer would just pull the motor and put a new one in (provided that Porsche chose to cover the issue). I've nver heard of a dealer rebuldling an engine in house after a IMS bearing failure.

DrBrain

I don't know if they put in a new engine, "rebuild" is the term that the Porsche service manager used. It is entirely possible that they put in a new one. BTW, the repair was covered by an extended warranty.

soverystout

I would bet the 3rd party insurer had them source a used engine and the parts list you have is all the things they needed to replace on the used engine.

All of the replacement engines put in by dealers were factory rebuilds, If I remember correctly.

Macster

I doubt the SM would write rebuild if the engine was replaced.

It is not unknown for a dealer to rebuild an engine that has suffered an IMSB failure as long as the engine is rebuildable. The factory issues guidelines the tech is to follow to determine if the engine is rebuildable.

I came across one such engine at a Porsche dealer. Besides the obviously bad IMSB the IMS was replaced along with one cam chain tensioner rail for the loose IMSB caused some excessive chain movement which damaged (but not severely) the rail (broke off some fragments of the composite plastic material these are lined with).

fpb111

I don't think we answered your questions:

By 2012 Porsche only replaced a 2004 engine's IMS with the larger, single row, upgraded (post 2005) IMS shaft and bearing assembly. It is/was very rare for the dealer to rebuild an engine. Most failed engines were replaced with "new", actually factory rebuilt, crate engines.
In those cases there won't be many parts on a replaced parts list.

If the car had a Porsche rebuilt engine installed it will Have an "AT" in the serial number.

Like this: M96/03AT66565123

M96/03 = 3.6

AT = Factory Rebuild

665 = 6 cyl, normally aspirated, 2005


"AT", which is not the normal format, might stand for "Austausch", which means "rebuild" engine.

http://www.renntech.org/forums/topic...e-sn-decoding/

If you have the new, improved, larger diameter bearing it cannot be changed without complete engine disassembly.

roadsession

I had a factory rebuilt engine put in my car by the Porsche dealer. The total number of pages was 2 because the part being replaced was the engine. It didn't come nearly close to 8 pages.

8 pages seems like engine was torn down and individual parts were replaced.