% of 997s for sale with rebuilt engines

Harryblue · 12 Mar 2025

Punchdrunked said:
FWIW, I believe that the rebuilt cars, especially the Hartech rebuilds, will command a premium in the future. Personally, I wouldn’t buy any 997 - .1 or .2, without an engine rebuild. Too much risk and constant worry otherwise.

It's irrational though, there is a risk but in reality it's tiny, everyone with a 996/997 spends half their life talking about bore score, but I rarely meet anyone that's actually had it, and even on the Facebook groups where people go on them specifically because they've had bore score only ever gets a dozen or so people saying they've had to have a rebuild and it's usually the same ones saying the same thing.

I go on drives with a couple of clubs in the Middle East and there must be over a hundred people with the M96/97 and I've never met a single one that's had bore score.

I'm sure there is a thread on here somewhere with someone that has been watching sales for a couple of years or so and it's something like 2.5% of advertised cars have had rebuilds.

Alex · 12 Mar 2025

You're looking in the wrong places. At least once a week I see someone with borescore on FB alone, especially in the engine guru group. There's a reason it's 4 to 6 months wait to get your engine rebuilt at Hartech.

R60BBA · 12 Mar 2025

Punchdrunked said:
I always chuckle at these types of comments. Replacing 3 liners and all the “while you’re in there” items is still going to cost at least £10k most likely more, as opposed to £15k. Either way, you’re not going to get the spend back come resale so it’s a waste of money anyway.

You’ll be hard pressed to find one of these cars with scoring on bank 2, so the programmatic approach will be to fix what needs fixing and try and limit your downside.

FWIW, I believe that the rebuilt cars, especially the Hartech rebuilds, will command a premium in the future. Personally, I wouldn’t buy any 997 - .1 or .2, without an engine rebuild. Too much risk and constant worry otherwise.

I don’t agree with your view but there is nothing wrong with two folk having a different opinion.

Harryblue · 12 Mar 2025

Alex said:
You're looking in the wrong places. At least once a week I see someone with borescore on FB alone, especially in the engine guru group. There's a reason it's 4 to 6 months wait to get your engine rebuilt at Hartech.

I've just gone back into that group to see when the last one was and there is so much noise I got bored reading stuff before I found a bore score issue, I remember one in Feb.
But it's run by Hartech and that's what they do, so you'd expect it to be almost exclusively about bore score, but from what I can see most M96/97 engines end up in the shop for something other than bore score.

Because it's such a hot topic I usually ask anyone I meet with a 996/997 if they've had bore score and the vast majority haven't.

I've got no reason to skew the info one way or another, but the FB 996/997 groups are trolled by about the same dozen or so blokes who do nothing but go on and on about bore score. I recognise their names now, I don't know them but as soon as I see the comments I notice the names and then it's a bore score fest.

There are tens of thousands of 996's and 997's out there, if only 10% were failing then there would be dozens in the shop every week, there aren't enough shops to cope with that sort of volume.

Roro · 12 Mar 2025

Well, if I ever end up with a rebuilt 997 Carrera, first mod will be a big "NO B-S" sticker on the back. Those that know, will know...

Punchdrunked · 12 Mar 2025

If you go on AT and eBay, you’ll find cars for circa £15k with full disclosure on Borescore. But when you enquire about the car invariably the engine is at the ticking stage which is way down the line in terms symptoms of scoring. Very rarely do you find a car where the ad says “scoring, sooty tail pipe but no ticking.” What that tells me is that there are a lot cars out there where the owners are driving them - a couple of thousand miles a year say, and park them up in winter. Oblivious, until it either starts tapping or a prospective buyer insists on a scope.

I used to be the world’s biggest skeptic on bore score. I thought it was a scam. So I bought one, and then realised that it is a problem. It doesn’t affect how the car drives, the oil pressure, the vital signs, so you think you can drive it and turn up the radio. But it doesn’t get better and the whole thing gets into your psyche - it’s always there.

Somehow Hartech and others found a solution to this problem. I mean, there’s a chap that’s just bought one where it had a Hartech rebuild 100k mikes ago and the bores are clean as a whistle today at 160k miles. That right there is what I’m talking about.

I’ve still got my 3.6 - it doesn’t smoke, use oil or tick. It’s great, but if I was in the market for another, it’ll be rebuilt car or go home.

Harryblue · 12 Mar 2025

I'm not saying that its any sort of scam, it's just that the claims of mass failures of sub-100k mile cars don't stack up, if they fail at the rates some people reckon then there would be tens of thousands of them parked up waiting for engine rebuilds and surely there would be a class action lawsuit like the IMS bearing?
If you talk to the garages or frequent the social media groups then there are plenty of 996 and 997 cars needing work, they're old cars now, but it's most often not because of bore score.

The discussion about scoring usually quite quickly has Hartech mentioned, and they've clearly put the work in to produce what appears to be the gold standard of remedy, their solution to fix the ones that have got scoring is top class and their capacity upgrade is brilliant as well, if I bring my 997 to the UK and keep it as our Euro touring car then I'll definitely take it to them for the upgrade.

My only challenge in this whole story is the numbers that are failing due to scoring, I can't find any kind of evidence or even anecdotal stories from owners that make me think it's more than even 10% that are failing.

Alex · 12 Mar 2025

I've just had a root round the forum. Back in 2009 there's posts about 997.1 engines being replaced by Porsche due to cylinder 6 failures with only 20k miles or so on them. This issues been around for at least 15 years. Hundreds of owners on here over that time subjected to it. It's an ever increasing number and a static production figure, so over time the overall percentage is just gonna rise. And as time/mileage goes on, it's gonna rise exponentially purely down to wear. They only made just over 100k 997.1 Carreras worldwide, so you're never gonna see tens of thousands stacked up, probably more been written off than scored bores.
If you were to say on average 1k cars suffered from it per year worldwide (which I think is a pretty fair assumption seeing as how 1 small outfit in Lancashire is in to 3 figures per year), then we'd easily be over 15% now.

Harryblue · 12 Mar 2025

Hard to get exact figures but they made at least 300,000 M96/97 engines that are all apparently going to fail with bore score.

15% would be 45,000 and there is no way that’s happened, I get about a lot and I would be seeing way more in shops being fixed and I guarantee there would be a US class action.

I think now we’re twenty plus years in we’re seeing these cars start to need more frequent repairs and maybe bore score is the Porsche prostrate cancer, (if you live for long enough then you’ll die of prostrate cancer but most men die of something else before that), so maybe if they run for long enough they’ll all eventually wear the bores out, but it’s not happening in the tens of thousands when they’re all under 100,000 miles.

drmark · 12 Mar 2025

Alex said:
I've just had a root round the forum. Back in 2009 there's posts about 997.1 engines being replaced by Porsche due to cylinder 6 failures with only 20k miles or so on them. This issues been around for at least 15 years. Hundreds of owners on here over that time subjected to it. It's an ever increasing number and a static production figure, so over time the overall percentage is just gonna rise. And as time/mileage goes on, it's gonna rise exponentially purely down to wear. They only made just over 100k 997.1 Carreras worldwide, so you're never gonna see tens of thousands stacked up, probably more been written off than scored bores.
If you were to say on average 1k cars suffered from it per year worldwide (which I think is a pretty fair assumption seeing as how 1 small outfit in Lancashire is in to 3 figures per year), then we'd easily be over 15% now.

Miy first "failure" due to scoring (sadly not the only one) happened in 2005 at just 7,500 miles. I had only had the car for 6 weeks before I noticed a problem with oil consumption and black exhaust. Only later learned that the first owner had it looked at a number of times by the supplying OPC for the same problem, and decided to get rid of it when changing the oil separator didn't fix it.
I was told it was a "bad piston ring" in cylinder 6 and that "oily bits can go wrong" and that it was "just bad luck". And I knew no different back then.

Harryblue · 12 Mar 2025

It happens for sure, I’m just trying to figure out what sort of percentages.

R60BBA · 12 Mar 2025

Harryblue said:
It happens for sure, I’m just trying to figure out what sort of percentages.

I don’t think you/anyone can without concrete evidence.

It’s a problem, but one that can mitigated.

There are cars out there with over 200,000 miles still running with no issues on the original engine and there were cars that suffered the problem when they were new. It is what it is.

I wouldn’t fuss about it (not saying you are).

Harryblue · 12 Mar 2025

R60BBA said:
I don’t think you/anyone can without concrete evidence.

It’s a problem, but one that can mitigated.

There are cars out there with over 200,000 miles still running with no issues on the original engine and there were cars that suffered the problem when they were new. It is what it is.

I wouldn’t fuss about it (not saying you are).

Yeah you’re right and I’m not really fussed, just curious and happy enough to chew the fat on it. With the data we have at hand it’s as much a discussion on psychology and marketing as it is about engineering.

Alex · 12 Mar 2025

Ive just looked on AT at 997 with over 125k on them. New engine or rebuild seems the common theme.

Harryblue · 13 Mar 2025

Alex said:
Ive just looked on AT at 997 with over 125k on them. New engine or rebuild seems the common theme.

Yeah I can totally believe that, the general consensus has always been that these engines are only good for 100k miles.

But that’s actually worn out, not early catastrophic failure. I remember some years back seeing a 996 engine on a bench and being told the big ends had gone, I was surprised but apparently that’s all you get from a modern Porsche engine. An old fella from the unit next door was laughing and saying that the Japanese had given people unrealistic expectations and 100k miles always used to be the cut-off for a rebore/rebuild.

Maybe that’s why there is this psychological glass ceiling of 100k miles for a car to drop in value, I still see plenty advertised just shy of 100k and you can see the owner is trying to punt it off before it clicks over into six figures.