The results are in: S6 reliability
Discussion
J_S_G said:
You KNOW it's had engine work done on it, which means I should probably have put it in the thumbs down category. However, I had to remove it from the stats as the history's unknown to an extent - it'd be wrong to put it in either column... Maybe it was preemptive cos he/she didn't want to take any risk at all. Maybe preemptive means it was burning oil at the same rate as petrol and he/she didn't want to wait the 20 extra miles it'd take for it to fail completely & start chewing up spark plugs, etc.
Along with the 2 that I put from "thumbs up" into "thumbs down" for head gasket failures, I think those are the only judgement calls I made. I'll check this again tonight to flag up any other calls I had to make. But feel free to question any of those.
Hmmmmmm...my first chim had a head gasket failure. Does that count as a Rover V8 engine failure. I dont think so. I thought the issue here was to get stats on the 'engine failure' issue and not the 'engine problem of any sorts' issue.
As far as I am aware my engine has had no rebuild, any pre-emptive work done was done by the previous owner on the basis of other Speed 6 engines going bang.
andyvdg said:
P.S. Very difficult to conclude much from this graph. Maybe try visually comparing the 6 month period started Jan '00 with the period starting Jul '02. Similar spread and number of samples, much fewer red ?
A large proportion of people haven't given the reason for rebuild. Would be great if we could show that, but I'm not sure if there's the quantity of data needed. I'll take a look tonight, though, and see if there's anything around this I can pull into a graph.
swilly said:
I thought the issue here was to get stats on the 'engine failure' issue and not the 'engine problem of any sorts' issue.
As far as I am aware my engine has had no rebuild, any pre-emptive work done was done by the previous owner on the basis of other Speed 6 engines going bang.
OK, you win... your d
ck's the biggest. 
Who's to say what other work was done when the headgasket was replaced? Who's to say that your engine wouldn't have gone bang if it hadn't been rebuilt.
If the head gasket goes, the engine has failed. It's not a 200mph car at that point, it's a lump of plastic and metal. It's off the road. In the garage. Needing repair. It's failed.
Maybe I'll just p
ss off and do my day job rather than trying to help out and stop the endless "it's only a small percentage"/"it's nearly all of them" debates. 
andyvdg said:
Another useful graph would show engines with multiple rebuilds, or the mileage since last rebuild. In other words something to show the probability of a rebuilt engine going again based on rebuild month or something.
Didn't capture the data in quite that way, but was going to add it in. Will definitely do that.
J_S_G said:
swilly said:
I thought the issue here was to get stats on the 'engine failure' issue and not the 'engine problem of any sorts' issue.
As far as I am aware my engine has had no rebuild, any pre-emptive work done was done by the previous owner on the basis of other Speed 6 engines going bang.
OK, you win... your d
Who's to say what other work was done when the headgasket was replaced? Who's to say that your engine wouldn't have gone bang if it hadn't been rebuilt.
If the head gasket goes, the engine has failed. It's not a 200mph car at that point, it's a lump of plastic and metal. It's off the road. In the garage. Needing repair. It's failed.
Maybe I'll just p
Now calm down.
You've gotten together a good set of data, which after years of 'The Speed6 is crap-no its great' type threads on PH, could actually give people a better view of the issue.
It has already been said on this thread that this info could polarise the two sides of the arguement. On the contrary I would suggest this info SHOULD be able to present a pretty reliable picture of the whole debate.
But you are beginning to cloud things. I am only suggesting you dont turn this data into a "30% of road deaths are due to speeding" type of spin.
I get my spark plugs changed at each service. That is pre-emptive. Does that count as an engine failure too.
edited to say I agree my dick is the biggests
>> Edited by swilly on Wednesday 8th September 10:06
As Ted said earlier, don't shoot the messenger. James has clearly put a lot of work in here, crunching this info into some meaningful helpful info, and I'm sure he could have been doing something else. Bottom line is, if you don't like what he's done, want it done in a different way, whatever.....you could always do it yourself !.
swilly said:
Now calm down.
You've gotten together a good set of data, which after years of 'The Speed6 is crap-no its great' type threads on PH, could actually give people a better view of the issue.
It has already been said on this thread that this info could polarise the two sides of the arguement. On the contrary I would suggest this info SHOULD be able to present a pretty reliable picture of the whole debate.
But you are beginning to cloud things. I am only suggesting you dont turn this data into a "30% of road deaths are due to speeding" type of spin.
I get my spark plugs changed at each service. That is pre-emptive. Does that count as an engine failure too.
edited to say I agree my dick is the biggests
Think there's a difference between a few pound bill for pre-emptive work on a wearable item, and what I'm assuming is a bill for several £k on a supposedly lifetime part. Can we agree to disagree on that and give the stats an accuracy of +/- 1?
Agree that we should be careful not to read too much into something as simplistic as a graph like that - it doesn't include how many owners thrap their engines from cold, etc. (Then again, I wonder how many Honda owners warm their engines up...)
To me, there's a simple statistic: about 40% of all S6 engines have needed serious engine-related attention.
Here's a new stat for everyone:
Only taking into account engines upto Dec-2001, 56 rebuilds, 23 no rebuilds. 67%.
hear hear, you can argue the toss over minor details but don't give JSG a hard time over technicalities. However you look at it, it's a depressing picture with no obvious pattern to it. It will be interesting to see things in 12 months time to see if the drop off at the end of the graph is due to a real fix or just lack of mileage.
M@H said:The raw data is available to anyone who can be bothered to make the effort to read the threads. If anyone wants to take issue with the analysis, why don't they do their own, and post the results here?
Another useful graph would show ...XYZ
It might be best to dish out your raw Excel data or you're going to get run ragged here I reckon
J_S_G said:Steady on JS - I think you made a typo there - should read
To me, there's a simple statistic: about 40% of all S6 engines have needed serious engine-related attention.
"about 40% of S6 engines in this survey have needed serious engine related attention."
Should keep the legal people off your's and Ted's backs.
Seriously, excellent work from you as ever.
We've debated this often, and while the limited mileage issues means this
can't be proven beyond doubt yet, I still believe, based on 'well founded
information' that 2003 - 2004 cars will make the grade.
Well, we should get our Tamora back soon after well over 2 months off the road. Most of the wait due to TVR Power who "lost" 2 sensors off the head when it went up to them to get the valve guides redone.
Luckily we are getting it done under warranty. Ben Samuelson finally authorised it - he's now in charge of warranties (don't ask!)
Hats off to Steve Howard for sorting all this out and dealing with a fair amount of stubborness from various parties on the way.
So, hopefully we get a sorted Tamora with 12k on it. Time to next rebuild? How long is a piece of speed 6?
Luckily we are getting it done under warranty. Ben Samuelson finally authorised it - he's now in charge of warranties (don't ask!)
Hats off to Steve Howard for sorting all this out and dealing with a fair amount of stubborness from various parties on the way.
So, hopefully we get a sorted Tamora with 12k on it. Time to next rebuild? How long is a piece of speed 6?
Well done JSG - major piece of work for no obvious reward.
The two big issues are: (a) is this sample representative in the first place (b) interpretation of the raw data - are all these rebuilds what I would regard as a rebuild. But it's difficult to believe that either of these are such fundamental flaws that the results can be ignored.
The two big issues are: (a) is this sample representative in the first place (b) interpretation of the raw data - are all these rebuilds what I would regard as a rebuild. But it's difficult to believe that either of these are such fundamental flaws that the results can be ignored.
J_S_G said:
Here's a new stat for everyone:
Only taking into account engines upto Dec-2001, 56 rebuilds, 23 no rebuilds. 67%.
That's more like the kind of Stat I was thinking this would throw up. Less an 'All Sp6 Engines are cr@p' and more an 'If you got an early one and you haven't had it rebuilt then you most probably will need to'.
Sorry if my earlier post wrankled JSG. This was a good piece of work. Shame we couldn't get a bigger population to work on
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