and another IMS question ....

[Hatzenbach]

two years ago my IMS failed on my MY 2002 Box S
Fortunately I had an extended warranty who paid for the new engine.
The replacement engine came from Porsche as factory rebuild engine "with all the upgrades". This happened in May/June 2009.
I understand that at one point Porsche went to a new IMS bearing which can no longer be replaced. Is there any way (w/o taking the tranny off) to figure out what IMS bearing my engine has?

[Wayne 962]

If your engine came from 2009, then almost definitely it has the new bearing that cannot be replaced. My Porsche factory crate engine was from about 2006-2007 or so, and it had the new bearing installed...

-Wayne

[Hatzenbach]

Thanks, that's what I thought.
Any idea how the failure rate is with the new bearings?

Thanks again
Chris

[Wayne 962]

No evidence, only some comments from Charles Navarro and Jake Raby stating that they have seen failures with this bearing as well.

-Wayne

[mikefocke]

that Porsche concluded that an IMS design was not a good idea after multiple designs had problems to some degree and so designed the IMS-less engine.

Enough failures that Charles decided there was a business case to be made for designing a IMS return and refurbish business even if the cost to the car owner would be significantly more than the earlier design simpler bearing and seal replace..

Those two decisions by people in the know would convince me there was some risk in the last IMS design.

[harryrcb]

Originally Posted by mikefocke

that Porsche concluded that an IMS design was not a good idea after multiple designs had problems to some degree and so designed the IMS-less engine.

Enough failures that Charles decided there was a business case to be made for designing a IMS return and refurbish business even if the cost to the car owner would be significantly more than the earlier design simpler bearing and seal replace..

Those two decisions by people in the know would convince me there was some risk in the last IMS design.

and that's one of the main reasons why I'm putting a gen2 motor in my Boxster besides the fact that it has lot's more horses and torque

[cnavarro]

Here you go. I have several others from shafts we've received in the shop to rebuild, but this is the first one I found. Luckily we can fix those easily, as the snap ring doesn't get buggered up as bad as on the earlier single rows after a failure.

[mikefocke]

think any engine generation problem free.

Take a look at Hartech | Porsche boxster engine repairs, Porsche engine repair, Porsche 996 engine repairs, Porsche engine problems section 5.

[Wayne 962]

Disappointing to see the same problem, that was supposedly fixed by Porsche.

-Wayne

[turboflyer]

Guess I lost it some where. I thought as of 2009 the IMS was gone. More conventional case and crank configuration. So the the poor bearing design permeates to the present?

[JFP in PA]

What Mike and Wayne are referring to is the last revision of the M96/97, which began in late 2005; so any later model car, or and earlier one with an engine replacement after 1/2006 has the large diameter IMS, which can only be changed by total disassembly of the engine; and are still failure prone. In 2009, Porsche dropped the M96/97 design and switched to the 9A1, which does not have an intermediate shaft, but appears to have some new problems associated with the timing chains. Only time will tell if it is as bad as the IMS.

[clickman]

Originally Posted by JFP in PA

Porsche dropped the M96/97 design and switched to the 9A1, which appears to have some new problems associated with the timing chains. Only time will tell if it is as bad as the IMS.

The devil you know ...

This just re-inforces my opinion that the best way to get into a Boxster is to buy a roller and pop a Raby M96 into it.

[intakexhaust]

Sooner or later most will continue to fail and by now its obvious Porsche will never admit why. Warranty and goodwill by Porsche is their prayer against time and its soon to be case closed for them. If they would admit the failure rate and the reason why, it would be catastrophic financially and their reputation would be on the line.

Pure and simple, this is a poorly engineered guarantee failure of a design. The fricken oil cannot escape the extreme pressure induced upon its load surface. Pressurized oil just ending at that bearing end? Think about it? Even installing some larger bearing wouldn't solve it and probably make it even worse!

Is a factory drawing or print available depicting the oil passages? If so, I would appreciate it. Thank you.

[mikefocke]

I'd be interested in any statistics you have to support your "most" assertion. My reading of the issue is quite contrary to yours. Can happen? Yes. Probable? No.

[turboflyer]

What would be outstanding is a twin turbo or supercharger V6 conversion. Any one doing that?

[mikefocke]

Originally Posted by turboflyer

What would be outstanding is a twin turbo or supercharger V6 conversion. Any one doing that?

Heat dispersion problems galore or more weight higher up in the chassis. Maybe why they aren't.

[Wayne 962]

Porsche is no stranger to engine problems and issues. These are no different than the ones in the past. I will refresh everyone's memory, as I wrote a book on all of these issues (with the air cooled engines)

1965-68 - Pretty good bullet-proof aluminum block

1969 - Weak magnesium cases, and an intermediate shaft bearing that wore through the mag block

1970-1977 Mag blocks that often pulled studs, had cylinder spigots that got out of alignment, and also had pulled head studs (1975-77 in particular, with the five-blade fan + thermal reactor fiasco). Some of these mag case engines leaked oil while still on the showroom floor!

1978-89 - Dilavar head studs breaking

1965-83 - All engines suffered from sporadic chain tensioner failure, which is similar in nature and destruction to this most recent IMS issue

1990-1998 - All 964s and 993s have valve guides that don't appear to last as long as the older models. This can cause soot to build up in the emissions system and cause a check engine lamp error.

1997-2008 - IMS, rear main seal, etc. Nothing unusual when compared to the past history of engine issues.

-Wayne

[Rockster]

I've been reading up a lot on the IMS issue and was wondering,
Is it true that the 1997 model Boxster was made in Germany and is more reliable then the ones made after in Finland?

[Wayne 962]

The later cars were indeed assembled in Finland, but I don't think there were any quality issues with these Finish cars. I believe that the engines were all built and assembled in Germany.

-Wayne

[jdiba]

Can you tell me if it was a Porsche extended warranty that footed the bill, or
was it a 3rd party warranty company, and if so who ? Am guessing you had
49k miles when the failure occurred ? thanks ahead of time.