date inputted: 04/03/2015
member: 955matt
model: targa
engine size: 3.6
purchased: July 2014
registered: Sept 2003
mileage at purchase: 59876
mileage now: 65789
bearing: original
Comment: speaking to more than a couple of porsche garages they say ims and bore scoring are not that common , mostly blown up on the Internet on forums ( what a surprise ) working in a landrover garage as a manager I dread the words I've been on the forums because they are full of rubbish. I'm not saying is doesn't happen just its not a common as people would make out.
The more we make of this the more it will hurt our pockets
Sorry just my two pence worth , I'll get my coat now
Matt
New997buyer Yas Marina
Joined: 17 Oct 2010 Posts: 8692
Posted: Thu Mar 05, 2015 6:29 am Post subject:
Ahem.....
A few passing comments have been made about the USA figures under the umbrella of 'fact'. Here's some fact%.
1) The figures quoted are for engine failure 'claims' not 'IMSB failure' rates. Anyone wanting to appreciate the difference either read some previous threads or a book and reliable data. ('Reliable data' is a clue).
2) The figures illustrate a 'claim' variance from 4% to 8% without stating how this is spread. So quoting 4% or 8# is just plain wrong. It's between 4-8%.
3) I point this out not to suggest IMSB isn't a very rare but serious event (which is where I think the debate should end). Instead it is me highlighting the lack of reliability in that data. That's good scientific method where you acknowledge the limitations in your approach. There are significant limitations in the USA data that affects its reliability. Just as there are in this poll and the one on pistonheads site.
Here's an extract from the Harris Case. Feel free to read it all:
The challenge with this whole issue is not just the lack of data, but the human incapability to process risk. And we have lots of reliable data on this. 1% and 7% will 'feel' the same to most as they fixate on the 'loaded chamber'. For more information on human cognition and flaws in interpreting and accepting risk read some behavioural economists like Thaler. For basics on heuristics and biases like Kahneman. For other related cognition flaws read behavioural psychologists such as Ariely). But to reiterate the problem isn't just with the problem in confirming if it's 1% or 10%. It's flaws in coping with risk itself. It's the inability to rationally deal with it. That's why you get these huge threads.
And much of the confdence held by some in their views on IMSB arise less from data and more from worldview.
Nothing on here will change that as it hasn't arisen because the data is unreliable (or where it has been collated reliably) but because humans are just rubbish at this stuff.
But it's a nice fun exercise so good luck with it. And it's nice to see thread extolling the many wonderful virtues of the 996. For me the low price of purchase is actually one
Mr Scruff Trainee
Joined: 26 Feb 2015 Posts: 80
Posted: Thu Mar 05, 2015 6:45 am Post subject:
May be a bit early to enter my stats as only just bought the car but...
date inputted: 05/03/2015
member: Mr Scruff
model: C4 Man
engine size: 3.4
purchased: Feb 2015
registered: 1999
mileage at purchase: 69,000
mileage now: 70,000
bearing: original - as far as I know. Nothing to say been changed
Comment: Leaking RMS changed but otherwise good as gold!
alex yates Brands Hatch
Joined: 06 Mar 2014 Posts: 13956 Location: The Ribble Valley, Lancashire
Joined: 24 Oct 2013 Posts: 361 Location: Essexboy at home.
Posted: Thu Mar 05, 2015 8:58 am Post subject:
I dont worry about this.However, chatting with my Very well known and respected Indy, when I collected my car after service.
I TRIED to spend some more money to have my IMS replaced.He told me not to bother.He couldnt even remember, replacing one, or rebuilding an engine due to IMS failure.That was enough for me.Im off the meds now, and drive my car with arrogant impunity!
alex yates Brands Hatch
Joined: 06 Mar 2014 Posts: 13956 Location: The Ribble Valley, Lancashire
Just a quick update from myself from the data collected as yet:
15 members who are current owners have provided data.
0 of them have had IMS issues within their ownership (0%). 2 owners have had bearings replaced as a safety measure and 1 owner has been led to believe it has (12 still believe they're on the original).
The average owner has owned the car for 441 days & covered an average of 6,165 miles.
The total miles all these cars had covered when purchased was 1,153,766 miles and have since covered 92,476 miles (1,246,242 miles to date).
The average mileage of these cars when purchased was 76,918 and to date is 83,083.
Engine size split is 3.4 - 33%, 3.6 - 67% (of which 47% standard & 20% X51 345hp).
I am totally aware that this data is not a true reflection of all ownership, but it is a snapshot in time of ownership of contributing members.
The more data we get off members, the more clearer the situation becomes for people (especially potential buyers who've had the heeby-jeebies scared out of them by typing porsche ims into google).
From this exercise, if nothing else, it will point potential buyers in the direction of who to buy a 996 off (contributing members)
Thank you to all contributing members, anybody who hasn't contributed relevant data, in the interest of process capability and 996 market value, please do so
(apologies if I've made any mistakes in my reporting). _________________ 2000 Manual 996 C4 Arctic Silver Convertible
alex yates Brands Hatch
Joined: 06 Mar 2014 Posts: 13956 Location: The Ribble Valley, Lancashire
A few passing comments have been made about the USA figures under the umbrella of 'fact'. Here's some fact%.
1) The figures quoted are for engine failure 'claims' not 'IMSB failure' rates. Anyone wanting to appreciate the difference either read some previous threads or a book and reliable data. ('Reliable data' is a clue).
2) The figures illustrate a 'claim' variance from 4% to 8% without stating how this is spread. So quoting 4% or 8# is just plain wrong. It's between 4-8%.
3) I point this out not to suggest IMSB isn't a very rare but serious event (which is where I think the debate should end). Instead it is me highlighting the lack of reliability in that data. That's good scientific method where you acknowledge the limitations in your approach. There are significant limitations in the USA data that affects its reliability. Just as there are in this poll and the one on pistonheads site.
.........
But it's a nice fun exercise so good luck with it. And it's nice to see thread extolling the many wonderful virtues of the 996. For me the low price of purchase is actually one
Thanks for your input Paul. Interesting to read about the American stuff. Which makes me think - did Porsche use the IMSB as a get out for bore-scoring?? What I mean is - did Porsche know bore-scoring was the big issue, but brushed it under the IMSB umbrella, knowing that they would then only have to pay out for engines that had gone pop with the IMSB and not for bore-score (which would have gost them $$$$$$ more?).
Which makes me think - did Porsche use the IMSB as a get out for bore-scoring?? What I mean is - did Porsche know bore-scoring was the big issue, but brushed it under the IMSB umbrella, knowing that they would then only have to pay out for engines that had gone pop with the IMSB and not for bore-score (which would have gost them $$$$$$ more?).
That's the problem with the Harris Case data. It's not just unreliable but it has significant issues of validity as well. Examples? Well you've mentioned some plus customer service pressure (it's the same time as the Cayenne was being heavily pushed with a 'can do attitude' being strongly enforced in the global dealer networks), the IMSB cases would have proven worrying / puzzling for service teams (for all the reasons mentioned on here and other places) so panic and poor categorisation may have occurred, other issues may have been getting lumped in for 'convenience' / ease, corporate arrogance / fear of failure etc etc etc etc. And all these are stated in the documents which state the source of the data on claims.
Now NONE these things could have happened and the Harris data is indeed an EXACT (though vague) measure of IMSB failure alone. But as presented that is a very big leap and those who make that claim are rightly challenged on reliability and validity. In other words as empirical data from which to generalise it is highly flawed.
Then we get into the whole secondary debate about can it be generalisable for the wider world from the USA. I'm NOT wanting that debate and it's NOT the point of this thread.
But in short I'd not want my GP working from such a poor evidence base as the Harris case data if he / she was prescribing treatment for me that's for sure. And let's not forget the way this whole thing works is if any one makes a claim (in this case it is a particular percentage of failure) then they have to back it up with appropriate evidence.
(Sorry )
alex yates Brands Hatch
Joined: 06 Mar 2014 Posts: 13956 Location: The Ribble Valley, Lancashire
Now come on fellow members - over a 1100 views in 24 hours and only 15 people can supply me with data _________________ 2000 Manual 996 C4 Arctic Silver Convertible
New997buyer Yas Marina
Joined: 17 Oct 2010 Posts: 8692
Posted: Thu Mar 05, 2015 2:10 pm Post subject:
Cheers!
I'd love to add mine but it wouldn't be current
(But it was 53k flawless and wonderful miles in a 2001 996.1.5 manual over 3 and a half years )
jonttt Shanghai
Joined: 20 Aug 2012 Posts: 4957 Location: Liverpool
On a serious note it is an interesting thought re the Bore Score being the real issue and assumed IMS failure data being skewed by that
I have always likened the Porsche IMS bearing issue to the BMW spinning shells failure in the S54 series ///M engines around 2001. Even more so given the recent thread which logically argued that manufacturing tolerance where a factor in early failures.
In the case of the S54 real world examples existed but the situation that the 996 now finds itself in was avoided by BMW "doing the right thing", admitting a manufacturing tolerance defect and retrofitting a fix under warranty FOC to early owners ie the issue, worry, impact on values, etc..... was nipped in the bud before it started.
How Porsche could effectively find a way to actually re-engineer the problem still beggers belief.
It is genuinely good to hear that so many current forum owners have not been affected by this _________________ "Imagination is more important than knowledge" Einstein
#lastoftheaircooled
1997 Porsche 911 993 C4S My Journal
2014 Porsche Boxster GTS My Journal
2017 BMW 740 Msport
2017 RR Evoque Autobiography
medicus Albert Park
Joined: 21 Oct 2014 Posts: 1518
Posted: Thu Mar 05, 2015 2:34 pm Post subject:
this is more like it Alex, WELL DONE.
its not superstition or scaremongering, its real world input from real world drivers, whilst full understanding its far from exhaustive or complete, as you pointed out its relevant to us and this forum, figures might well change, but I can now (for the time being) take the "galaxy" badge of the back, and replace with a frys Turkish delight one.
Lee H Trainee
Joined: 26 Oct 2014 Posts: 78 Location: Manchester
date inputted: 05/03/15
member: Lee H
model: 996 2 C2
engine size: 3.6
purchase date: 01/11/14
date registered: 27/04/02
mileage (at purchase): 73850
mileage (now): 74295
bearing (orig./replacement): Original
failure data (if applicable):
Comment: previous owner on here had car for 2 years and 14k miles with no issue. I've hardly used the car due to poor weather.
alex yates Brands Hatch
Joined: 06 Mar 2014 Posts: 13956 Location: The Ribble Valley, Lancashire
Thanks Lee _________________ 2000 Manual 996 C4 Arctic Silver Convertible
Chris_in_the_UK Paul Ricard
Joined: 19 Mar 2014 Posts: 3481 Location: Harrogate
Posted: Thu Mar 05, 2015 4:00 pm Post subject:
Can a humble Gen. 1 Cayman S play?..... _________________ 2006 Cayman S PCCB's
New997buyer Yas Marina
Joined: 17 Oct 2010 Posts: 8692
Posted: Thu Mar 05, 2015 4:42 pm Post subject:
jonttt wrote:
'real world examples existed but the situation that the 996 now finds itself in was avoided by BMW "doing the right thing", admitting a manufacturing tolerance defect and retrofitting a fix under warranty FOC to early owners ie the issue, worry, impact on values, etc..... was nipped in the bud before it started.
One thing we do know for certain from the Harris Case is the number of claims. The figures are of claims paid out. Isn't this evidence of Porsche 'doing the right thing'..........?
(Sorry, Alex, I know that this isn't the point of this thread...... )
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