mkaresh

What would be the value of knowing how many IMS failures occurred in the past? What most people most want to know is how many have been failing recently.

No one has to "scurry to the computer" to ensure that a failure is reported. Participants receive a regular email with a link to the survey. When they receive the email, they take a minute or two and fill out the survey. It's just not that complicated.

Similarly, if the car has been sold when the ex-owner receives the email they report this and any final repairs or unrepaired problems.

Because of the regular prompts provided by the emails, we get a much higher response rate than the typical survey.

It's true that I cannot speak to the past failure rate. But it's now clear that, with the Boxster, the failure rate over the past year has been just a few cars per hundred.

Bruce is partly right about the precision of this survey. We cannot report that the faiure rate is 5% vs 3% or 7%. But I think it's safe to say that, over the course of the past year, it's under 10%, and probably under 5%.

OZ951

Personally I am not interested in how many failed this year I'm interested in how many have failed period because the failures appear to happen at a variety of ages and mileages. I have no problem with the survey your running by the way - even if some 'experts' do. As far as I'm concerned it's a bit more information and like everything else I take it with a grain of salt.

Sneaky Pete

Well that's a new tactic....agree with your detractors. Taking my seat back on the couch.

redridge

awwwwww Geez!

mkaresh

Different mileages, certainly, but these are all present within the past year. We would need a far larger number of reported failure to also look at the mileages at which they occurred, though.

Different ages is another matter--it's no longer possible to buy a 996 that's just a few years old.

I can see how it would be interesting, if not necessarily useful, to know the failure rate over time back to when the cars were new. But to do this would require doing without the methods the survey uses to prevent distorted results.

As it is, I hope it is just helpful for people to know that the failure rate over the past year is fairly low, if certainly not zero.

Also note that these were results for the 986, not the 996. Hoping to start having some for the 996 in February.

Palmbeacher

I believe what most of us want to know is how likely is our car, or one we contemplate buying, to fail. Therefore the most meaningful statistics would relate the failure rate to model year, age and mileage @ failure, and driving and service/maintenance histories (avg speed/rpms, oil-change interval and oil type used, etc.). Knowing how many have been failing recently is absolutely meaningless because of all the other variables, particularly the wide range of mileages oweing to the large number of these cars that are not daily drivers. It's incomprehensible that you don't understand that. You may be a fine and knowledgeable statistician in the sense of compiling data, and if that is your only goal, fine. Most of us would like to be able to relate, interpret, and draw conclusions from such a compilation, and unfortunately your methodology (as has been pointed out a number of times by a number of people) inhibits doing so in any meaningful way.

ivangene

mkaresh

Would it be more useful to know the effects of these variables? Absolutely.

But I don't see that some overall stats without these variables are "absolutely meaningless" when the overall failure rate over the past year is just a few percent. It's not conceivable that any common factor would result in a high failure rate, at least not in the near term, when the overall failure rate is so low.

Also, you claim to want to know more, but posts like yours have the opposite effect.

ivangene

know where lightning struck and how hot it was and wide it was and how long it was and how long it lasted and how bright it was and the temprature and relative humidity, barometric pressure, moon phase, sun spots, and what you ate for dinner 3 weeks ago and what "that guy over there" thinks about it will not give you any more ability to know when and where it will strike again

just accept there is no way to know and you either dont have a failure, or you do - some cars will last 1,000,000,000 miles and some wont make it 10,000 - your choice is to live with it, prevent via some sort of replacement, cover yourself with protection, dont drive it, sell it, or lay in bed and cry... in the end you just have to pick one and do it

My vote goes towards just getting a warranty and driving it till it blows the hell up - or preventing if that is not an option

Palmbeacher

I and others can give you the explanation, but clearly we can't give you the understanding. The fact you don't (or refuse to) comprehend to such a basic and essential concept, is precisely what undermines your credibility. As it is, you are merely amassing a pile of data, with no correlational value whatsoever.

Posts like mine have no effect whatsoever on you, who appears to remain blindly and stubbornly adamant to your own false notions. Thus I must agree with Ivangene that there is, to-date, no reliable means of predicting the likelihood of failure(s), nor is your data going to change that. His conclusions are the only viable ones which can currently be drawn.

Divot

If it is around 5% per annum, then half of the 01s, and 60% of the '99s would have failed. I don't think that is correct, but it's your study.

LVDell

ah crap, I had no idea I was still subscribed to this. Unsubscribing so I can check out more meaningful thread like what oil to use

BruceP

This datum says the failure rate may be an estimated 5-10%... among a voluntary sample... excluding those whose engines failed before signing up... taken exclusively from people who frequent internet forums... in numbers that even with a designed sample would produce a double digit margin of error. On the basis of the latter point alone, 5% in this study could therefore mean 20%. Or nearly 0%.

Sorry, guys, but there is no way this study or any like it will give you a prediction for failure rate. Add to these statistical problems the fact that the failure rate over time for this engine very probably plots as a bell curve, and nobody but God in his heaven can tell you what your odds are of a future failure.

You know two things: Your engine will eventually fail for one reason or another. And you will eventually do the same. So go for a drive and enjoy yourself.

ivangene

well put its about like trying to figure either of those out.... and in the end if you could figure out exactly when your expiration date was (scientificly) that doesnt mean you wont get run over by a bus and never see the science tested

Marlon

...no more ticking-time-bomb in my car - engine replaced !!!