Welcome to 911UK
The only place for Porsche, 911uk is the definitive enthusiast and resource site for the Porsche 911.
Registration is fast, simple and absolutely free, so join up today for full access to the site and benefit from latest member offers.

Porsche Classifieds
Porsche Buyers Guides
Sell Your Porsche on 911uk
Create a Free Classified Advert
Search Ads
Classified Adverts FAQ
Trade Classified Information
Buyer & Seller Fraud Protection
Consumer Rights Act
Pre Purchase Inspection (PPI)
Porsche Car Sourcing
Porsche Cars Wanted
Official Porsche Centre Reviews
Model
Stock
Porsche 911
991 : 2011- 19
997 : 2004- 91
996 : 1997-2005 44
993 : 1993-1998 5
964 : 1989-1993 2
Carrera 3.2 : 1983-1989 0
Carrera SC : 1977-1983 2
930 Turbo : 1975-1989 0
Early 911 : 1964-1977 3
Porsche Other Models
Classic : 1950-1965 0
Boxster : 1997- 14
Cayman : 2005- 16
Cayenne : 2003- 8
Macan : 2014- 0
Panamera : 2009- 1
912-914-924-928-944-968 1
959 - CarreraGT - RaceCar 1
Car Parts For Sale & Wanted
Other Items For Sale & Wanted
Wheels Tyres For Sale & Wanted
Number Plates For Sale Wanted

Porsche Services
Porsche Body Shop Repair
Paint Protection & Wrapping
Porsche Classic Insurance
Porsche Classic Parts
Porsche Classic Restoration
Porsche Design Collection
Porsche Engine Gearbox Rebuild
Porsche Heritage & History
Porsche News
Porsche Picture Gallery
Win a New Porsche 911

Porsche Parts
Body Parts, Body Styling
Brakes, Clearance
Electrical, Exhausts
Engine Cooling, Engine Electrical
Engine Rebuild, Heating Cooling
Interior Incar, Lighting
Rubber Seals, Service Parts
Steering, Suspension
Transmission, Workshop Tools
Early 911, 911 - 930, 928 - 968
964 - 993, 996 - 997, Boxster
Cayman, Cayenne, Panamera

Porsche Model Range
911 [991] 2011-Current
Porsche 911 [991]
911 [997] 2004-Current
Porsche 911 [997]
911 [GT] GT1-GT2-GT3
Porsche 911 [GT]
911 [996] 1997-2005
Porsche 911 [996]
911 [993] 1993-1998
Porsche 911 [993]
911 [RS] RS-RSR
Porsche 911 [RS]
911 [964] 1989-1993
Porsche 911 [964]
911 3.2 1983-1989
Porsche 911 3.2 Carrera
911 SC 1977-1983
Porsche 911 SC
911 [Early] 1964-1977
Porsche 911 [Early]
Boxster & Cayman
Porsche Boxster & Cayman
Cayenne & Panamera
Porsche Cayenne & Panamera

911uk Site Partners

Post new topic   Reply to topic
Author Message
alex yates
Brands Hatch
Brands Hatch


Joined: 06 Mar 2014
Posts: 14468
Location: The Ribble Valley, Lancashire

2000 Porsche 996 Carrera 4

PostPosted: Tue Apr 28, 2015 7:27 pm    Post subject: Reply with quote

Data collected so far for 72 cars (28th April 2015).

Here's a couple of bar charts showing which engines and models have sustained a failure:

Total number of failures - 8.3% (Not including the LN as a original failure)
of which 3.4 - 0% and 3.6 - 11.3%
of which all X51 - 0%, C2 - 11.8% and C4S - 13.3%



Last reported failure was July 2014 (not including the LN failure).
I'm starting to wonder if the reported failures are anything to do with Porsche moving to a 2 year/20,000 mile service plan around the same time they were registered Dont know


_________________
2000 Manual 996 C4 Arctic Silver Convertible




Last edited by alex yates on Tue Jan 02, 2018 4:14 pm; edited 1 time in total
 
  
View user's profile Send private message
   
GT4
Nordschleife
Nordschleife


Joined: 08 Nov 2008
Posts: 30194
Location: Hertfordshire and Hampshire


PostPosted: Tue Apr 28, 2015 9:59 pm    Post subject: Reply with quote

Clean oil and proper levels contribute to mitigate IMS failures, so that is not a bad hypothesis.
 
  
View user's profile Send private message
   
jm24
Monza


Joined: 29 Mar 2015
Posts: 154
Location: London


PostPosted: Tue Apr 28, 2015 11:35 pm    Post subject: Reply with quote

Agree two year intervals are likely to be a contributing factor, but find it unlikely that all those cars which had IMS failure wouldn't have if they'd had more regular oil changes.. I reckon a fair few 04 owners still go for annual servicing anyway.
_________________
Midnight blue '04 C4S
 
  
View user's profile Send private message
   
alex yates
Brands Hatch
Brands Hatch


Joined: 06 Mar 2014
Posts: 14468
Location: The Ribble Valley, Lancashire

2000 Porsche 996 Carrera 4

PostPosted: Wed Apr 29, 2015 6:08 am    Post subject: Reply with quote

For what an oil change costs it's a no brainer (price of filling a tank of fuel). Why risk the cost of an engine failure Dont know
_________________
2000 Manual 996 C4 Arctic Silver Convertible


 
  
View user's profile Send private message
   
Chris_in_the_UK
Estoril


Joined: 19 Mar 2014
Posts: 3509
Location: Harrogate


PostPosted: Wed Apr 29, 2015 7:25 am    Post subject: Reply with quote

jm24 wrote:
Agree two year intervals are likely to be a contributing factor, but find it unlikely that all those cars which had IMS failure wouldn't have if they'd had more regular oil changes.. I reckon a fair few 04 owners still go for annual servicing anyway.


You are contradicting yourself?
_________________
2006 Cayman S PCCB's
 
  
View user's profile Send private message
   
jm24
Monza


Joined: 29 Mar 2015
Posts: 154
Location: London


PostPosted: Wed Apr 29, 2015 5:11 pm    Post subject: Reply with quote

Chris_in_the_UK wrote:
jm24 wrote:
Agree two year intervals are likely to be a contributing factor, but find it unlikely that all those cars which had IMS failure wouldn't have if they'd had more regular oil changes.. I reckon a fair few 04 owners still go for annual servicing anyway.


You are contradicting yourself?


I simply meant that of those 2004 cars that did switch to bi-annual servicing and had IMS failure, the less frequent oil changes were still only a contributory factor. I.e its an inherent design fault (albeit over hyped) for which oil change frequency can influence the risk of failure.

It would be interesting to know the service intervals of those 2004 models that have failed to see what proportion had annual/bi-annual servicing Question If they all had the bi-annual servicing it would certainly give more credence to the hypothesis
_________________
Midnight blue '04 C4S
 
  
View user's profile Send private message
   
Shurv
Albert Park


Joined: 09 Jan 2013
Posts: 1727
Location: Northampton


PostPosted: Thu Apr 30, 2015 3:23 pm    Post subject: Reply with quote

It is interesting to see how many bearings were replaced and noted to be perfectly sound. I've been reading an interesting thread on Rennlist where the Merkins seem to fanatically replace the IMS as the stateside 996 engine guru states it is essential to do so. They are investigating a failure of the ceramic bearing solution which has lunched an engine. Our own 996 engine guru (Baz Hart) doesn't advocate changing is essential, even though he has a solution himself. It'd be interesting if the ceramic solution turns out to be as risky as the original Porsche design.
It is also interesting to note that the majority of failures are with cars serviced every 2 years.
Great work Alex, the bore score one will be even more interesting, but, can we pick up whether manual or tip? Thumb
_________________
996 C4S Arctic Silver Black leather
 
  
View user's profile Send private message
   
jm24
Monza


Joined: 29 Mar 2015
Posts: 154
Location: London


PostPosted: Thu Apr 30, 2015 7:13 pm    Post subject: Reply with quote

But we don't know that the majority of cars were serviced every two years do we? We know the majority had 2 year service schedules, but theoretically could have all had annual services in this sample..
_________________
Midnight blue '04 C4S
 
  
View user's profile Send private message
   
Chris_in_the_UK
Estoril


Joined: 19 Mar 2014
Posts: 3509
Location: Harrogate


PostPosted: Thu Apr 30, 2015 7:57 pm    Post subject: Reply with quote

jm24 wrote:
But we don't know that the majority of cars were serviced every two years do we? We know the majority had 2 year service schedules, but theoretically could have all had annual services in this sample..


Which, again given your earlier contradiction may be largely irrelevant.
_________________
2006 Cayman S PCCB's
 
  
View user's profile Send private message
   
jm24
Monza


Joined: 29 Mar 2015
Posts: 154
Location: London


PostPosted: Thu Apr 30, 2015 11:54 pm    Post subject: Reply with quote

Chris_in_the_UK wrote:
jm24 wrote:
But we don't know that the majority of cars were serviced every two years do we? We know the majority had 2 year service schedules, but theoretically could have all had annual services in this sample..


Which, again given your earlier contradiction may be largely irrelevant.


I don't see any contradiction and went on to explain what I was getting at. Feel free to explain what you specifically see as contradictory, but I'd just like to have as much understanding of the contribution of oil change frequency to IMS failure as possible.

Unless we know how many of the failed 04 cars were serviced bi-annually, we are making assumptions about the extent to which oil change can/does influence IMS failure. Perhaps they were all bi-annually serviced in which case it would look like a very significant factor. If though say half still had annual servicing, then its a somewhat different story. I'd just like to have as informed idea as possible.
_________________
Midnight blue '04 C4S
 
  
View user's profile Send private message
   
911munKy
Nürburgring


Joined: 26 Nov 2014
Posts: 473



PostPosted: Fri May 01, 2015 7:11 am    Post subject: Reply with quote

JM24,
I think there may be some confusion over 'bi-annual'.

Bi-annual = Occuring twice in a year, I believe you are referring to servicing every 2 years/20,000m having an impact on IMSB longevity.
 
  
View user's profile Send private message
   
jm24
Monza


Joined: 29 Mar 2015
Posts: 154
Location: London


PostPosted: Fri May 01, 2015 10:21 am    Post subject: Reply with quote

911munKy wrote:
JM24,
I think there may be some confusion over 'bi-annual'.

Bi-annual = Occuring twice in a year, I believe you are referring to servicing every 2 years/20,000m having an impact on IMSB longevity.


Thanks 911Munky, technically that's right, although it is often used both ways.. not helpful though so will avoid it for service interval related discussions!
_________________
Midnight blue '04 C4S
 
  
View user's profile Send private message
   
alex yates
Brands Hatch
Brands Hatch


Joined: 06 Mar 2014
Posts: 14468
Location: The Ribble Valley, Lancashire

2000 Porsche 996 Carrera 4

PostPosted: Thu Jun 25, 2015 2:13 pm    Post subject: Reply with quote

Data collected so far for 77 cars (25th June 2015).

Here's a couple of bar charts showing which engines and models have sustained a failure:

Total number of failures - 7.8% (Not including the LN as a original failure)
of which 3.4 - 0% and 3.6 - 10.9%
of which all X51 - 0%, C2 - 10.5% and C4S - 12.9%



Last reported failure was July 2014 (not including the LN failure).

[/quote]
_________________
2000 Manual 996 C4 Arctic Silver Convertible


 
  
View user's profile Send private message
   
alex yates
Brands Hatch
Brands Hatch


Joined: 06 Mar 2014
Posts: 14468
Location: The Ribble Valley, Lancashire

2000 Porsche 996 Carrera 4

PostPosted: Fri Oct 09, 2015 8:40 am    Post subject: Reply with quote

Data collected so far for 87 cars (9th October 2015).

Here's a couple of bar charts showing which engines and models have sustained a failure:

Total number of failures - 6.9% (Not including the LN as an original failure)
of which 3.4 - 0% and 3.6 - 9.4%
of which all X51 - 0%, C2 - 9.5% and C4S - 11.1%



Last reported failure was July 2014 (not including the LN failure).


_________________
2000 Manual 996 C4 Arctic Silver Convertible


 
  
View user's profile Send private message
   
Robertb
Long Beach


Joined: 01 Sep 2003
Posts: 6718
Location: South Oxfordshire

2002 Porsche 996 Carrera 4S

PostPosted: Fri Oct 09, 2015 9:26 am    Post subject: Reply with quote

It would be interesting to invite Boxster/Cayman owners to contribute too- presumably they share the same IMS bearing.

Are we brave enough to start a Bore Scoring survey for Alex to run his spreadsheet magic?

We could update our original posts with bore scoring yes/no.
_________________
"911- the guilt-free supercar"

Current: 2003 C4S Coupe, seal/black

Ex: '02 C4S Coupe, '96 993 Targa, '88 Carrera Sport Coupe
 
  
View user's profile Send private message Send e-mail
   
alex yates
Brands Hatch
Brands Hatch


Joined: 06 Mar 2014
Posts: 14468
Location: The Ribble Valley, Lancashire

2000 Porsche 996 Carrera 4

PostPosted: Fri Oct 09, 2015 9:42 am    Post subject: Reply with quote

I was planning on doing a bore score thread but think that should be kept separate. Only thing not motivating me to do it is the fact I don't have a 3.6 Wink
_________________
2000 Manual 996 C4 Arctic Silver Convertible


 
  
View user's profile Send private message
   
alex yates
Brands Hatch
Brands Hatch


Joined: 06 Mar 2014
Posts: 14468
Location: The Ribble Valley, Lancashire

2000 Porsche 996 Carrera 4

PostPosted: Tue Mar 08, 2016 10:27 am    Post subject: Reply with quote

12 Month Review


Data collected so far for 92 cars (8th March 2016).

Here's a couple of bar charts showing which engines and models have sustained a failure:

Total number of failures - 6.52% (Not including the LN as an original failure)
of which 3.4 - 0% and 3.6 - 9.1%
of which all X51 & C4 - 0%, C2 - 9.1% and C4S - 11.1%





Last reported failure on a 996 was July 2014 (not including the LN failure).


_________________
2000 Manual 996 C4 Arctic Silver Convertible


 
  
View user's profile Send private message
   
Niall996
Imola


Joined: 07 Nov 2010
Posts: 839
Location: Paris


PostPosted: Tue Mar 08, 2016 11:30 am    Post subject: Reply with quote

I'd love to see the correlation between 'failures' and 'first time posters' on 911uk as well. Could be my imagination but it often seems to be someone who never posted before or who posted minimally who suddenly pops up on a Porsche forum with IMS issues. And then quietly vanishes a short while thereafter. Along with their car, their story, the outcome etc.
 
  
View user's profile Send private message
   
Costelles
Newbie


Joined: 08 Jun 2014
Posts: 27



PostPosted: Thu Mar 10, 2016 7:08 am    Post subject: Engine failure Reply with quote

My 2002 Targa had a new engine from Porsche in late 2011, reason was cracked cylinder #6

54k miles at the time
 
  
View user's profile Send private message
   
Shurv
Albert Park


Joined: 09 Jan 2013
Posts: 1727
Location: Northampton


PostPosted: Thu Mar 10, 2016 4:29 pm    Post subject: Reply with quote

It also looks like the later the car, the more it fails. Could this be something to do with the 2 year service intervals being brought in?.
_________________
996 C4S Arctic Silver Black leather
 
  
View user's profile Send private message
   
Display posts from previous:   
Post new topic   Reply to topic   All times are GMT - 12 Hours
Goto page Previous  1, 2, 3, 4, 5  Next
Page 2 of 5

 
Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You can attach files in this forum
You can download files in this forum
You cannot post calendar events in this forum