Bore Scoring - Cayman S Gen 1 - Page 2 - Boxster/Cayman - PistonHeads UK

Hey folks, I know this an issue that has been discussed many times on here... But bear with me. I had a 2011 Cayman S Black Edition until recently and sold it to free up some funds, I now have a 130i and though it's a good car it's quite a way off a Cayman so I'm seriously considering a Gen 1 car. I saw one that looked very appealing (2006, 60k-ish miles), I got it inspected and the boroscope inspection revealed 'striations' in cylinders 1 and 5. The person who inspected it discussed with an independent Porsche engine specialist who said this is probably similar to most cars of this age and mileage. The problem is no one can say if these striations will progress to scoring or if they've been there for 10,000 miles and will stay there till 120,000. I was told by the person who inspected mine (Peter from No5 Garage, seems a very nice guy) that most people don't get the boroscope done so he can't say himself it's fairly routine to have some striations. I really like the car, it has a fairly unique spec so I considered taking the risk and offering a significantly lower amount than the asking price. However the owner feels there is nothing wrong with the car because it drives fine and has no tell tale signs of bore scoring (no smoke on start up/using oil/rattle/spark plugs blackening) so he's still wanting the full asking price, or thereabouts. I'm quite sure it'll go for near the asking price to an unsuspecting buyer which is a bit sad but the owner is confident in the car. My question is how many of you have had your Caymans inspected via boroscope and seen striations/scoring? If you have seen either has it progressed to a problem or just continued to drive as normal? I realise there will be a small sample but I'm just trying to get an idea because there's another Gen 1 Cayman I like the look of (2005, 60k-ish) and I'm considering getting an inspection including boroscope. If on the inspection there is some striations/scoring then I guess it is average but I'm trying to save myself another £400-ish. I wish I could stretch to a Gen 2 but there's a minimum £10k difference for the spec I want (PASM and SC). Thanks in advance for any input.

It is very difficult to identify bore scoring even when you have looked at hundreds of bores and even more difficult if you are not using your own camera in your own workshops as different cameras and angles etc vary the view and photos sent over the Internet vary as well. It has always been bank 2 (cylinder 4 to 6) that score so almost never bank 1 (cyls 1 to 3). If you are inspecting a car that has been fitted with Nikasil cylinders you often will see lines of shading that would indicate bore scoring in Lokasil but are not in Nikasil because the surface finish of Nikasil is more reflective than Lokasil and shows up different polish marks with more definition. We have had several engines sent to us diagnosed with 1 to 3 scored bores that were perfectly OK - so it is a difficult area. They will run OK for several thousand miles after initial bore scoring before evidence is obvious. Baz

anonymous said: [redacted] Thanks for the reply. I take your point re: PASM and SC, I had both on my Gen 2 and felt on 19s PASM made a big difference but I don't mind smaller wheels. I felt there was a significant lag in throttle response without SC switched on but I guess there are other ways to improve that like you mentioned. Even without them there's a massive difference in price of a 2006 Cayman (14-17k) and 2009 gen 2 (24-28k). Didn't realise it only affected 3-6, so may well be 'normal'.

hartech said: It is very difficult to identify bore scoring even when you have looked at hundreds of bores and even more difficult if you are not using your own camera in your own workshops as different cameras and angles etc vary the view and photos sent over the Internet vary as well. It has always been bank 2 (cylinder 4 to 6) that score so almost never bank 1 (cyls 1 to 3). If you are inspecting a car that has been fitted with Nikasil cylinders you often will see lines of shading that would indicate bore scoring in Lokasil but are not in Nikasil because the surface finish of Nikasil is more reflective than Lokasil and shows up different polish marks with more definition. We have had several engines sent to us diagnosed with 1 to 3 scored bores that were perfectly OK - so it is a difficult area. They will run OK for several thousand miles after initial bore scoring before evidence is obvious. Baz Appreciate the reply. I actually called your place and spoke to Rob (I think that was his name) and he said that it may well be 'normal'. I'm assuming you have scoped many cars, would you say that the striations (not scoring) are common on cars with 60-70k miles. From what I've read on here the reason bore scoring happens seems to be a design fault so would that mean it will eventually happen to almost all the Gen 1 3.4/3.8 engines? Let's say above 150,000 miles. Or have you done scopes on many high mileage cars and they've been fine. Thanks

^^ Baz - many thanks. Your concise contributions to this thread are the most useful information I've ever seen on this issue.

We've seen bore scoring at under 15K and not seen it on over 100K (although piston coatings are getting well worn by then). It seems dependent on several factors one of which is the piston temperature reached affecting the piston coating bonding strength, the load between the piston and cylinder bore, the ambient temperature and the rate of heat soak caused when stopping for a while after a spirited drive. Added to that we think there is a variability of the distribution and bonding strength of the silicon in the cylinder walls. It is clear that if all the drivers from new never thrashed the car - always warmed it up before thrashing it, never exceeded UK National speed limits, didn't give the car full throttle while accelerating (especially in a tiptronic where slipping into first helps before setting off fast), whatever the quality and distribution of the silicon in their Lokasil - their engine would last longer. But these cars should be able to be driven fast and so how it was driven and a random quality element may all make predictions very hard. Some new owners drive very modestly and so their cars have a higher proportion that will last longer but some also can afford to treat a new expensive sports car with contempt and cause a lot of premature deterioration. You can help by lowering the running temperature with a low temperature thermostat, third radiator (as long as it also has a control valve or thermostat), thicker oil viscosity as the mileage increases etc but there is still unfortunately a random element that can bite any owner at any time - but numbers failing are still very low and there are warranties and maintenance systems that could reduce the cost if it occurred to you. Good luck, Baz Edited by hartech on Wednesday 23 September 10:17

interesting…. wife has mentioned we should get a porsche(shes always liked them).But i am in the 996/caymen gen 1 price range wise, and being able to buy one and run one seem to be poles apart.The engine is the biggest worry for me ,if it went bang I coudn't afford to repair it.

As a 2.7 Cayamn owner I would agree that the engine seems solid enough at 60 k miles, BUT make sure you,have a warranty or big war chest to cover the cost of the other bits which fail. Buy a car based on 60% of your budget and keep the rest for fixing it! So far I've had new battery, water pump, steering pump, idler pulleys, window regulators, a/c condensers, clutch switch, distribution box, exhaust studs and coolant hose replaced in the first 14 months of ownership. Most of that under warranty.

Yes the 2.7 is more reliable because there is less heat generated at the piston crown, more space for coolant in the jacket, lower cylinder coolant and piston all oil temperatures and higher oil viscosities, less pressure pushing the piston against the cylinder wall and more owners choosing a 2.7 because top speed is not their main issue and therefore they are less likely to be thrashing the engine anyway. The cylinders are also more stable as they are of a smaller diameter but similar wall thickness. Baz

^^ Again, concise and useful information.

anonymous said: [redacted] Then again you can't shift them for love nor money. Mines been the cheapest one up on Autotrader and PH of it's kind for a while and all I've had are test pilots to date. Amusingly I had someone offer me £12k for it... So it seems the stigma of it being an expensive time bomb (which it isn't) has stuck to the 2.7 also. For example: peter2704 said: interesting…. wife has mentioned we should get a porsche(shes always liked them).But i am in the 996/caymen gen 1 price range wise, and being able to buy one and run one seem to be poles apart.The engine is the biggest worry for me ,if it went bang I coudn't afford to repair it. One of the cheapest performance cars I've ever run. Then again that's not everyone's experience I suppose. AndrewsCayman said: As a 2.7 Cayamn owner I would agree that the engine seems solid enough at 60 k miles, BUT make sure you,have a warranty or big war chest to cover the cost of the other bits which fail. Buy a car based on 60% of your budget and keep the rest for fixing it! So far I've had new battery, water pump, steering pump, idler pulleys, window regulators, a/c condensers, clutch switch, distribution box, exhaust studs and coolant hose replaced in the first 14 months of ownership. Most of that under warranty. Man that seems excessive! Admittedly mine's done half the milage (and is stored in a garage over winter), but outside regular consumables I've had the SPP amplifier repaired and a AC hose replaced. That's it. Soon as the warranty expired I never renewed it due to excessive cost vs actual risk of catastrophic failure (most other parts can be replaced as you would any other car). That's not to say it won't be without costs. If you're using a car things will wear out. But I don't think you need to pay through the nose for an OPC warranty as really that only makes sense if you're expecting an engine failure, which they'll not pay out for anyhow. As Baz says above, the 2.7 is far less prone to problems than other Caymans.

I suspect you're right. I'm brokering it via a friend at the moment as I really can't be doing with muppets. But to drop the price I'd have to sell it myself (obv he's factoring in a commission, warranty and the fact that he's doing all the legwork in the price it's listed at). Might have to bite the bullet and DIY

anonymous said: [redacted] Did you run through your 100% engine failure theory to these 15 buyers, who weren't previously aware of it? How did the sale go?

hartech said: We've seen bore scoring at under 15K and not seen it on over 100K (although piston coatings are getting well worn by then). It seems dependent on several factors one of which is the piston temperature reached affecting the piston coating bonding strength, the load between the piston and cylinder bore, the ambient temperature and the rate of heat soak caused when stopping for a while after a spirited drive. Added to that we think there is a variability of the distribution and bonding strength of the silicon in the cylinder walls. It is clear that if all the drivers from new never thrashed the car - always warmed it up before thrashing it, never exceeded UK National speed limits, didn't give the car full throttle while accelerating (especially in a tiptronic where slipping into first helps before setting off fast), whatever the quality and distribution of the silicon in their Lokasil - their engine would last longer. But these cars should be able to be driven fast and so how it was driven and a random quality element may all make predictions very hard. Some new owners drive very modestly and so their cars have a higher proportion that will last longer but some also can afford to treat a new expensive sports car with contempt and cause a lot of premature deterioration. You can help by lowering the running temperature with a low temperature thermostat, third radiator (as long as it also has a control valve or thermostat), thicker oil viscosity as the mileage increases etc but there is still unfortunately a random element that can bite any owner at any time - but numbers failing are still very low and there are warranties and maintenance systems that could reduce the cost if it occurred to you. Good luck, Baz Edited by hartech on Wednesday 23 September 10:17 Hi could you please advise what oil would you recommend be good on a 25k c4s with the third radiator,Thanks..

anonymous said: [redacted] It was a genuine question! Chill Winston!

anonymous said: [redacted] ?????????????????

anonymous said: [redacted] I hit one of these a few years ago in a 350Z. Damage came to £1400!! Tough little buggers.

Kin el!!

I'd love to know what percentage of cars have experienced problems. One of the great things about forums is that people like me who are not handy with the spanners get free advice from fellow forum users and experts like Hartech etc. The bad thing is that the devil makes work for idle hands and the same problems seem to be discussed so often that you'd think every car had these issues. I bought mine with no research or knowledge of this issue, it's been good as gold and although I would consider myself to be 100% honest and genuine, I don't think I'd feel compelled to point this issue out to a potential buyer unless my car was exhibiting any of the tell-tale signs. I suspect as another reply suggested, most people are oblivious to the problems - probably a good thing because if every car was considered a ticking time-bomb with a £10k bill somewhere down the track, they'd all be worthless......

I had a 996 C4S which had a replacement engine, OPC supplied at 40k odd miles. I had the car for around 15k if i remember rightly and sold the car on Ebay. I was at the time abroad so missus dealt with the detail. At the time i was open about the fact the car had a replacement engine and since then was all kept up to date with OPC servicing. Sold it last Mar never to be heard of again. Had a email last week from a new owner who bought it off the guy who bought it off me. Said it was still going strong, i think now on 80k. I told him the history of the car etc. Those who want a Porsche at that age should know the foiables and i would rather be up front with it and whats happened. If the buyer doesnt think its for him then his loss.

Pagoda1966 said: the same problems seem to be discussed so often that you'd think every car had these issues. I think that's the tricky thing about the whole "Porsche sportscar = chocolate engine" issue. We know it exists but have absolutely no idea What proportion of cars has been affected to date, or How likely any particular car is to suffer the bore scoring issue. It's on the second of these points that the inputs from Hartech to this thread are interesting. My interpretation is that the most vulnerable car is likely to be a 3.4 which has been thrashed from cold or run very hot, then switched off. As regards the proportion of cars affected I guess only Mr Porsche knows - and isn't saying. Meanwhile he's perfectly happy to collect £500 p.a. as an aftermarket warranty fee and encourage owners to keep their cars in the official dealer network.

hartech said: We've seen bore scoring at under 15K and not seen it on over 100K (although piston coatings are getting well worn by then). It seems dependent on several factors one of which is the piston temperature reached affecting the piston coating bonding strength, the load between the piston and cylinder bore, the ambient temperature and the rate of heat soak caused when stopping for a while after a spirited drive. Added to that we think there is a variability of the distribution and bonding strength of the silicon in the cylinder walls. It is clear that if all the drivers from new never thrashed the car - always warmed it up before thrashing it, never exceeded UK National speed limits, didn't give the car full throttle while accelerating (especially in a tiptronic where slipping into first helps before setting off fast), whatever the quality and distribution of the silicon in their Lokasil - their engine would last longer. But these cars should be able to be driven fast and so how it was driven and a random quality element may all make predictions very hard. Some new owners drive very modestly and so their cars have a higher proportion that will last longer but some also can afford to treat a new expensive sports car with contempt and cause a lot of premature deterioration. You can help by lowering the running temperature with a low temperature thermostat, third radiator (as long as it also has a control valve or thermostat), thicker oil viscosity as the mileage increases etc but there is still unfortunately a random element that can bite any owner at any time - but numbers failing are still very low and there are warranties and maintenance systems that could reduce the cost if it occurred to you. Good luck, Baz Edited by hartech on Wednesday 23 September 10:17 Apologies for the late response. Thanks for this info. I guess I'll have to keep looking and try to find without bore scoring and do what you suggested.