alexb76

This + 1000!

BogdanR

I don’t know… I’m more of a “luck favours the prepared” kind of “worry less and enjoy more” kind. Some are the “ignorance is bliss” kind…
Perhaps my engineering background is to blame here :-)

Lvt19672

If the ims will keep you up at night then don't get a 997.1 and move up to a 997.2

Bruce In Philly

This stuff can weigh on you. After my first engine blew in my purchased-new-Boxster at 47K miles, I refused to track it anymore. Too bad. I still enjoyed the car and always drove it aggressively (where appropriate) but would not longer track it. The worry was always on my mind and absolutely effected my use of the car.

I would say to myself, "just get to 200K chassis miles and I won't care". Well, wouldn't you know the second engine blew at 197K. All the years I watched closely to see when and if Porsche would design a new engine and sure enough, they did. So..... I purchased a 2009 used.

Do you remember what Porsche did, marketing wise, before the DFI engine was released? They leaked those engine testing videos showing the new engine roaring on a test horse being flipped 90degrees in all three dimensions. This, IMO, was a very calculated video release.

Peace
Bruce in Philly

BogdanR

That stuff won't weigh on me at all Bruce. When you expect the worst, all the surprises can only be good, right ? :-)

Or something like that...

BogdanR

Waiting to pick up my car is keeping me up at night so far. IMS won't.
I'll be OK, don't worry about me. Besides if you read my opening post and my replies more closely, you'll find worry was not the reason I started this thread in the first place...

gripshifter

I still don't think we have even one confirmed case of an '06 or later 997 with the revised larger bearing having an IMS failure. No hearsay or rumors, but a confirmed case....

myw

it's on the forums, ive seen/read cases here and on 6-psd. its more rare then with the smaller accessible bearings but it happens.

Fred R. C4S

Bruce in Philly,

Let me see if I've got this straight. You had a catastrophic engine failure at 47,000 miles. Not good by anyone's measure.

You next had a catastrophic engine failure at an engine life of 150,000 miles.

As a retired ME, I've got to ask what engine life in a sports car are you expecting? What should the design goal be? What is an "acceptable" failure rate of engines not meeting your target.

Nothing lasts forever. Things wear out. Maintenance gets postponed or missed. Owners sometimes do dumb things. With this in mind, how long should an engine last, and what should it cost?

You've got every right to be upset by an engine only lasting 47,000 miles assuming nothing was done to or with the engine that was abnormal. But I take it that you were not satisfied with a 150,000 service life.

BogdanR

The issue here is not parts failing but rather how they fail and how serviceable they are given the fact their failure totals the engine.

Good design practice would have such critical parts in a conservative maintenance schedule and keep them reasonably accessible. People would still groan but ultimately work those parts into their cost of ownership. No big deal really.

Current state of affair for those affected models however makes the whole engine a replaceable part on a completely unpredictable schedule. That or a messy and costly engine tear-down/ rebuild. Whatever the definition of reasonable, this is the complete opposite.

That's the issue.

Fred R. C4S

I suspect that under truth serum, the engine designers in Stuttgart would admit that the IMS was a a huge mistake. A blunder of epic proportions. But I think they found themselves designed into a corner. Without throwing out the design and starting over, they could only redesign within the envelope they had to work with.

I also suspect that this whole blunder started life as a cost reduction proposal. They probably sat around the conference table and talked themselves into believing it would be fine. Then the unintended consequences manifest themselves well after production had commenced and they had a mess on their hands. The statisticians then sat around and extrapolated the little available data, and made everyone feel better. It then took a new engine design to properly address the problem by designing it out of the engine.

It's all a very sad story. Trust me, in my 36 years working in design, development and support of complex mechanical machines, this happens more often than you think. I have sat at the conference table and watched otherwise educated and sensible men talk themselves into something equivalent of believing the world to be flat.

I forgot to mention that other phenomena that occurs in the corporate world. The folks guilty of proposing this terrible design were most likely promoted for the brilliant thinking and cost savings. Meanwhile, the innocents were punished by forcing them to try to make this dreadful idea work.

BogdanR

I think I've explained all that somewhere above, admittedly with less panache you have :-).
I'm part of the same engineering world and I know how it feels. I've been told by someone in such a meeting that sliding is more efficient than rolling... however believe me it is absolutely heart wrenching when you actually think you have a good design and all of the sudden you're facing an unexpected and unpredictable failure mode. No engineer worth its salt will willingly design a fault in a system, and even if the bean-counting upper management make him take a stupid cost cutting measure into consideration, he'll do his darnedest to actually make it work or at the very least make it easily serviceable.

What happened with these engines is probably a combination of what we talked about in this thread... and when they started getting alarming failures from the field in a spot they did not expect much if any trouble, they had way too many parts already in inventory and enough costly tooling supporting all their manufacturing to make abandoning this platform a financially untenable avenue. It was at this time meetings like the ones you're suggesting have started taking place...

The rest is history...

Bruce In Philly

Excellent question!..... I have wrestled with this one and don't have a solid answer as my emotions and intellect are in conflict - classic cognitive dissonance. So, here are my expectations.... reasonable or not, it is where my head and emotions are: 200K miles for minor stuff. Maybe an engine "rebuild" at that point, but able to keep it going.

So..... my requirement of 200K was met with my Boxster. Therefore, I should feel totally ok with it, and now just move on. But somehow I am not satisfied and am a bit angry at Porsche. Why? It is because the components that failed were catastrophic KABOOM parts that could not be detected nor addressed through simple, expected preventative maintenance as would be described in the manual.

1 - I paid $63K for that Boxster and I have expectations of quality. Quality is more durable parts (not just prestige). Is 200K a reasonable expectation provided by a higher price?... I think so.... Other cars like my old Honda, a much cheaper car and built 10 years earlier was doing really well at 150K miles and way cheaper than my Porsche at that level..... hmmm... apples to apples? I dunno. My 2009 C2S had an original sticker of $110K !!!! Yikes!!! I may by out of line here, but for double the money, I expect an even higher service life.
2 - I have an expectation... not sure it is totally reasonable.... that if I took the approach of fixing every problem and maintaining to the letter, that I would get a lifetime of service out of the car. Sure, you can say I could just replace that engine and my objectives will be intact.... but here is the rub.. I feel the failure was an unreasonable failure... a KABOOM failure. er... two KABOOM failures.
3 - Expectations did not meet outcomes. When I purchased this car, Porsche had a reputation as having "bullet proof" engines. Fantasy? My indy, who worked at a Porsche dealer and now has 25+ years with this brand said "I never saw a Porsche engine fail unless it was from neglect.. it was very rare... nothing like these new engines". Jim Ellis Porsche in Atlanta, where my 1st failure occurred, had a poster in their service department that read something like "All Porsche parts are race tested"... clearly a reference to long lasting, stronger than anything else stuff.

These KABOOM failure modes are what really upset me. I saw a teardown of an early 60s Ferrari sedan's engine and the "important" surfaces showed 0 wear (I believe the car had just north of 100K miles on it). The body was shot. The important surfaces I am referring to were the crank surfaces that rested against the races in the engine block that were fed with pressurized oil via little holes in the races themselves. I believe this is called a plain bearing. The other was the cam shaft lobes...... perfect!!!! Why is it unreasonable for me to expect that the KABOOM components be built a little tougher than say a pump or a piston ring?

For 200K lifetime, I then expect engine components to fail but be repairable. Even if expensive. I desire that certain components of a car be made extra durable.. as already is done in the case of safety-related items such as suspension, braking and steering parts. The KABOOM parts in the engine should fall into this extra-durable category. And for this, Porsche failed, hid it, and waited 11 years to really fix the issue(s) (BMW admitted an issue and distributed an extended 100K warranty to back their product).

For the flip side, I replaced maybe three (four?) coolant tanks in my Boxster, with the last failure requiring a flat bed. Sure I was annoyed, but the car wasn't killed by this either. Why couldn't they just make the plastic thicker after a few years of failing? I find this a quirk and nothing to be angry about as it was not a KABOOM part. So my point is that not all parts are equal and that "something has to be the first to go" is not valid when applied to all parts.

So, go ahead and flame away.... I fully understand that I may be unreasonable here. So go ahead, and set me straight.

Peace
Bruce in Philly

Kero

Hi Bruce!

I don't know your full history with Porsche. You mention that you have a 09 C2S now. My understanding is that this car has the 9A1 engine which does not suffer from the IMS issue/design. Did your 09 C2S engine fail as well? Is there something about the 9A1 which you feel will make is unrepairable ?

Fahrer

The only potential negatives I am aware of with the new engine are the following;

1. Problems with the HPFPs but this should issues should fade.

2. Some have reported high oil consumption ( even compared with previous models)

2. DFI and soot/sludge buildup concerns. This remains to be seen but has shown up in VW/Audis, BMWs and other brands with DFI.

3. My understanding is that the main bearings cannot be serviced which is only a factor for 'keepers' that get high mileage.

None of these, however, are catastrophic issues.