997.1 owners. How many are problem free ?

997.1 owners. How many are problem free ?

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Discussion

Eleven

26,271 posts

221 months

Friday 27th March 2015
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mickyveloce said:
That these (regular) posts are here at all signifies both frustration and disappointment for me as a Porsche enthusiast.

The company built a reputation on diligent and top quality engineering principles and, as a consequence, made some superb sports cars; the very best in the world.

However, at the turn of every key, if the owner is listening for unwanted noises, and at the finish of every journey the priority is to check exhaust pipe colours, then what's the point.

That Porsche re-engineered the 997.2 engine at all is an admission that the earlier unit had inherent issues, and the constant need for reassurance in threads like this one will continue to steer potential 996/997.1 owners towards less worrisome pleasures.
Blissfully unaware of the potential issues I had two years of pleasure from my 997.1.

fastgerman

1,911 posts

194 months

Friday 27th March 2015
quotequote all
Eleven said:
mickyveloce said:
That these (regular) posts are here at all signifies both frustration and disappointment for me as a Porsche enthusiast.

The company built a reputation on diligent and top quality engineering principles and, as a consequence, made some superb sports cars; the very best in the world.

However, at the turn of every key, if the owner is listening for unwanted noises, and at the finish of every journey the priority is to check exhaust pipe colours, then what's the point.

That Porsche re-engineered the 997.2 engine at all is an admission that the earlier unit had inherent issues, and the constant need for reassurance in threads like this one will continue to steer potential 996/997.1 owners towards less worrisome pleasures.
Blissfully unaware of the potential issues I had two years of pleasure from my 997.1.
Porsche re-engineer all of their engines in new models....

Otherwise we'd have 1.5 ton 991's with 100 bhp ;-)

spyderman8

1,748 posts

155 months

Friday 27th March 2015
quotequote all
mickyveloce said:
That Porsche re-engineered the 997.2 engine at all is an admission that the earlier unit had inherent issues...
I think Porsche would say they re-engineered to introduce Dfi driven by the obligation to reduce emissions.

fastgerman said:
Porsche re-engineer all of their engines in new models....
Except when the 987 came out and they continued to use the M96 engines.

Nihkasilma

4 posts

113 months

Friday 27th March 2015
quotequote all
mickyveloce said:
That these (regular) posts are here at all signifies both frustration and disappointment for me as a Porsche enthusiast.

The company built a reputation on diligent and top quality engineering principles and, as a consequence, made some superb sports cars; the very best in the world.

However, at the turn of every key, if the owner is listening for unwanted noises, and at the finish of every journey the priority is to check exhaust pipe colours, then what's the point.
The point is that, as enthusiasts, we still live in the aforementioned era you mention, whereas Porsche seem to be more worried about profits since the near collapse pre Boxster which is understandable, its just such a shame for the original "Reliable German Car"

drmark

4,794 posts

185 months

Friday 27th March 2015
quotequote all
mickyveloce said:
That these (regular) posts are here at all signifies both frustration and disappointment for me as a Porsche enthusiast.

The company built a reputation on diligent and top quality engineering principles and, as a consequence, made some superb sports cars; the very best in the world.

However, at the turn of every key, if the owner is listening for unwanted noises, and at the finish of every journey the priority is to check exhaust pipe colours, then what's the point.

That Porsche re-engineered the 997.2 engine at all is an admission that the earlier unit had inherent issues, and the constant need for reassurance in threads like this one will continue to steer potential 996/997.1 owners towards less worrisome pleasures.
Porsche still makes great cars. We have been lucky enough to own most Porsches - from 911s 2.2 to GT3 - over the years and we have kept the 997 the longest. Love it.

Plu Tony M

29 posts

118 months

Friday 27th March 2015
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The 997.1 is brilliant despite the inherent problems. We live in an age when everything is expected to be perfect all of the time. Engineering, by it's nature, is rarely perfect. I know as I test 'design engineering' on a daily basis. This car is great. Yes it can bite you in the arse, and wallet, but do you want a bmw 320d relationship with your 911?
The 997.1 will become a modern classic and it's faults, real and exaggerated, will be ignored and accepted and embraced.

mollytherocker

14,365 posts

208 months

Friday 27th March 2015
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zulash said:
i would just like a bit of feedback from owners who have a 997.1 that has NOT yet fallen foul of the ims/bore score problems. also if the car is an early model or fitted with the larger bearing. (if there are any)
I am not sure what you are expecting? You have asked for posts form people who havent had blow ups and people who havent had blow ups are posting?

There are thousands that havent blown up.

zulash

Original Poster:

202 posts

109 months

Friday 27th March 2015
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mollytherocker said:
I am not sure what you are expecting? You have asked for posts form people who havent had blow ups and people who havent had blow ups are posting?

There are thousands that havent blown up.
there is no end of moaning regarding the 997.1 basically i'm looking for owners that have no complaints about the 997.1 Posts on PH is all but 'writing off' the 997.1 it's no wonder certain cars depreciate. there are countless Porsche enthusiasts out there that absolutely adore the marque and in particular the 911. a vast percentage of those people can't afford the 997.2 which we all know is an improved engine.(add 16k on the price of 997.1). i've just bought a 997.1 Carrera c2 and she is stunning! I would just like to see other enthusiasts enjoy the same experience. i sometimes wonder if the owners of 'problem free' cars even know about PH!

zulash

Original Poster:

202 posts

109 months

Friday 27th March 2015
quotequote all
Plu Tony M said:
The 997.1 is brilliant despite the inherent problems. We live in an age when everything is expected to be perfect all of the time. Engineering, by it's nature, is rarely perfect. I know as I test 'design engineering' on a daily basis. This car is great. Yes it can bite you in the arse, and wallet, but do you want a bmw 320d relationship with your 911?
The 997.1 will become a modern classic and it's faults, real and exaggerated, will be ignored and accepted and embraced.
THIS IS THE KIND OF POST I WAS HOPING FOR. beer

mollytherocker

14,365 posts

208 months

Saturday 28th March 2015
quotequote all
zulash said:
there is no end of moaning regarding the 997.1 basically i'm looking for owners that have no complaints about the 997.1 Posts on PH is all but 'writing off' the 997.1 it's no wonder certain cars depreciate. there are countless Porsche enthusiasts out there that absolutely adore the marque and in particular the 911. a vast percentage of those people can't afford the 997.2 which we all know is an improved engine.(add 16k on the price of 997.1). i've just bought a 997.1 Carrera c2 and she is stunning! I would just like to see other enthusiasts enjoy the same experience. i sometimes wonder if the owners of 'problem free' cars even know about PH!
Most 997.1 owners love and enjoy their cars. Of course they do, why shouldnt they?

You should enjoy yours too. Dont worry about what is said on here.

csmith319

372 posts

162 months

Saturday 28th March 2015
quotequote all
Plu Tony M said:
The 997.1 is brilliant despite the inherent problems. We live in an age when everything is expected to be perfect all of the time. Engineering, by it's nature, is rarely perfect. I know as I test 'design engineering' on a daily basis. This car is great. Yes it can bite you in the arse, and wallet, but do you want a bmw 320d relationship with your 911?
The 997.1 will become a modern classic and it's faults, real and exaggerated, will be ignored and accepted and embraced.
Definitely don't want a 320d relationship - my 320d engine (owned from pretty much new and serviced properly its whole life) had to have £5500 worth of work at 80k miles and then blew up (hole punched in the engine block) 5k later and so needing a new engine! Main difference is probably that BMW paid for 90% of the costs despite it being 4 years out of warranty....

jakesmith

9,461 posts

170 months

Saturday 28th March 2015
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Mine's not been great but no engine issues. Its a 55 plate 4s cab v high spec, bought with 30,000 and has had new ignition switch, 4 new coils, alternator cable, pse valve, gearbox, door membrane. Bought for 35 and woukd sell private for 30 now so happy days.

Tim Netherton

452 posts

239 months

Saturday 28th March 2015
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I've had my 2006 C4S for just under a year.

71K - 5K of those by me.

In that time had 2 new rads fitted, new tyres all round, major service including brake fluid change.

No engine problems so far.

Each drive feels like a special event and I'm thoroughly enjoying being an owner of one of the world's greatest sports cars.

driving

ilduce

485 posts

126 months

Saturday 28th March 2015
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It's incredible that reaching 40 or 50k in a Porsche without major problems is seen as something worth mentioning. Considering the bhp/cc it's hardly overstressed and should last 100k, otherwise what are you paying all that money for?

drmark

4,794 posts

185 months

Saturday 28th March 2015
quotequote all
ilduce said:
It's incredible that reaching 40 or 50k in a Porsche without major problems is seen as something worth mentioning. Considering the bhp/cc it's hardly overstressed and should last 100k, otherwise what are you paying all that money for?
Not sure getting to 40-50k is worth shouting about - it is just people saying that is where they are, and so far so good.

As for what you are paying for? Less trouble than you would get from a Ferrari I suspect - 360 only puts out 50bhp more and doing 50,000 miles in one of those costs far more, scoring or no scoring.

schaeffs

321 posts

141 months

Saturday 28th March 2015
quotequote all
I think people are just stating their mileage...

C2S - 40k - on Hartech Gold maintenance plan - 18 months of awesome driving with only a gear link issue ruining the perfect mechanical record.

Absolutely love the car - potters around town most of the time but gets a good thrashing whenever it can. As I do on every car I've owned - warm up to oil temp before exploring the upper reaches of the Rev range - other than that it's treated normally and all the better for it.

Truly special car and whilst you won't see prices going through the roof as Porsche made too many of them its a future classic indeed. Special to own and drive.

hartech

1,929 posts

216 months

Monday 30th March 2015
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In answer to C moose (and some overseas e-mails I have received on the subject) - there is a correlation in the USA/Canada that suggests there is an increased incidence of bore scoring in very low temperature conditions down to -30 degrees C and it has been suggested that this is due to cold clearances.

I have some doubts about the cause and have an alternative explanation.

Firstly we have to be clear that there are two types of cylinder damage - (1) a seizure in which the piston gets too large for the bore and when this happens both sides of the piston seize/score or scuff into the cylinder and the engine stops turning over – often locking the rear wheels.

(2) We have the extremely rare and unusual bore scoring condition (compared to most engine types) that occurs in these engines and that only affects one side of the piston and bore. It is unusual because it is clear that the other side of the piston has sufficient lubrication not to score a bore and the other side does and that the piston has not grown too big for the bore yet scuffs up the thrust side only (remember this). There is no difference in the piston or bore material on one side or the other - nor is there any difference in fuel, ignition, compression or power - so you have to ask yourself - what phenomenon is it that roughs up one side of the bore so badly yet leaves the other side completely unmarked and doesn't result in the piston growing too large for the cylinder bore and seizing?

We know it only occurs on the thrust side (so this is a clue) and we also know it almost always happens on bank 2 where our internal temperature tests show that the thrust side of bank 2 runs hotter (in some circumstances) than the thrust side of bank 1.

We must also factor in the fact that these cylinder bores are known to gradually grow oval (up to 0.25mm or so before cracking) and therefore that the clearances in the thrust direction get bigger as the cars age (and while the piston coating gets thinner and the silicon particles in the cylinder bore area become less securely entrapped in the matrix)

We also know that these particles of silicon can occasionally escape from the matrix on the surface of the bore and because we have frequently stripped and rebuilt test engines to inspect the piston coatings on engines that we have built with different piston coatings (in the same engine) and we have seen the scratches in the surface of the pistons that have not yet torn off the coating (or worn it down) but must be caused by something!

So one major question that I cannot answer is do these "cold climate" scores only occur on bank 2 and as a typical one sided piston score - or either bank and on both piston sides. If it is former (as I suspect it might be) then it is difficult to blame piston to bore clearances - and there must be some other explanation!

When engineers are faced with problems like this - they try and find a link between what they observe and statistics, what they understand of dynamics and science - a link to common sense and logical deduction and their experience. Often different theories result and eventually they get knocked down until one or two remain - often unresolved as people stick doggedly to one explanation to prove they were right.

I am not claiming that my explanation that follows - is right - only that it fits in with my experience and some scientific logical deduction - but like the third radiator making engines run hotter at the thrust face in some circumstances - it initially seems not to make sense - but bear with me!

I think we have explained well enough why a third radiator actually raises the temperature at the thrust face of bank 2 (proven also during our tests) which seems like nonsense but is perfectly justified and proven by any analysis of thermodynamics and a degree of thought - and that this is all a combination of the consequence of having the thermostat at the entry to the engine and therefore reducing the coolant flow (to try and raise the temperature) when the available radiator cooling capacity is too high.

It is also a consequence of unusually arranging for the coolant flow to the cylinders being a small fraction (10% under full flow conditions) of the total coolant flowing through the engine (the vast majority of which only passes in and out of the cylinder heads)

Our tests have already demonstrated that at normal driving in the UK ambient conditions (between around 5 and 18 degrees C) in town or country driving spiritedly up to around the legal limit of 70mph - only one of the two (or three) radiators is needed to cool the engine - the "spare cooling capacity" only being required on hotter days or following behind other cars or after slowing down following a fast run.

Just imagine what the cooling through the radiators can be like with air at -30 degrees passing across all the radiators! This would make the thermostat be almost fully closed and the coolant flow through the engine be minute in the extreme. With the thermostat almost closed the coolant is passing through the radiators so slowly it cannot help but become over cooled and preserve the situation. With the coolant flow already severely reduced we look at the shape of the split of coolant flow between the heads and the block.

For those unfamiliar with the design - the feed to the cylinder head area is like 6 round tubes 20mm diameter (area 314.2 mm sq), whereas the feed to the cylinders is like a small slit or slot in the side of the tube measuring 4.8mm* 6mm (example cyl 4) which is 28.8 mm sq or 9% of the coolant passing through the cylinder heads. That is 9% IF fluid dynamics allowed the area only to govern the flow. But we all know that a small slot in the side of a straight tube (and at 90 degrees to it) will not flow pro-rata and especially when the pressure and flow rate are down - when a small fraction of that will flow (indeed there are some circumstances in which it is not impossible for the flow to almost cease).

Now most liquid cooled engines have all 100% of the coolant flowing through the block first and then on to the cylinder head (as does the GT3 and Turbo variants, 944's, 968's etc and I hope the Gen 2 engines as well?). So this is a significant and major design change from most previous engines and although we have been the only people to identify it and worko ut the significance of such a dramatic design change - we believe it not only has a significant influence on bore scoring (hence the LTT and our third radiator thermostat housing) but could explain this apparent increase in extreme cold weather bore scoring.

I can think of no other reason for bank 2 to exclusively be the location of bore scoring than this. We did test the oil spray jet directions and changed them and the volume and doubled the flow but this made no difference (so was not the cause) but there is a permanent and test proven difference in the temperatures of the thrust face of bank 2 being higher than bank 1 and when the coolant flow is really low - the cool coolant still hits the thrust face of bank 1 first and of bank 2 last.

It seems to me that if you design a sports car with huge performance potential (that needs large radiator capacity for those extreme conditions) that must also work in town and sub zero conditions (when you only need a really small radiator) - then you should add into the system - some control of the radiator capacity through stage rated thermostats to each or automatic roller blinds (similar to the manual ones Saab fitted to their two stroke cars for the same reason many decades ago - they really understood the issues!).

I think the sub zero conditions could result in such low coolant flow into bank two thrust face area that the temperatures just there rise too high and create the same conditions that lead to bore scoring in other conditions (possibly worse). You would not notice this because after leaving the cylinder block that coolant mixes back with the flow from the cylinder heads (anywhere between say 90 and 95% of it) and creates an insignificant temperature increase by the time it the mixture reaches the standard engine temperature sensor.

Unfortunately good engineers get a kind of mental block when they believe in one solution (making it difficult for them to consider someone else's alternative) and we are no different - however at least there is some consistency in our explanation and is does identify a huge difference in the thermal design of the engine cooling that we do not see elsewhere and links it specifically to why the problem could occur in hot, warm or cold weather.

I/we could be wrong of course as we have no experience of such low temperature driving conditions (although I would not imagine high revs and power are used and engine revs and coolant pump speeds would be low anyway) - and I guess the experiences of other similar engines that do have all the coolant passing through the cylinder block first would be a good comparison if just low temperatures are the explanation (as they too should show similar bore scoring problems)?

The key to working this out and deciding for yourself is to try and explain why it is bank 2 that suffers and why only the "hot face" of the piston gets scored (or scuffed).

Food for thought guys for which I anticipate some interesting responses!


Baz

.

hartech

1,929 posts

216 months

Monday 30th March 2015
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You see the problem when people are locked into one solution/explanation - if the problem was because of very cold weather and loads and clearances why does it not affect bank 1 as much as bank 2?

From Cold the cylinder block and piston start out at the same temperature and clearances are OK. One benefit of an open deck cylinder is that the exterior block temperature would have less affect on the cylinder bore expansion (as it is standing free).

Intake air will be sub zero also and hits the piston on entry to the engine and you would not expect loads to be high because you would reasonably expect drive to be limited - so with bore clearances already larger due to creeping ovality - it seems unlikely that the piston is growing so large in the cylinder than it would create enough friction to seize up and if it did I would expect it to be all round the piston and bore and both banks!

Indeed with bank 2 generally accepted to run hotter - it should be bank 1 failing if it were general overall piston to bore clearances that cause the problem.

I repeat I simply don't know who is right but I have linked a lot of facts all of which agree with my scenario - including general points about radiator capacities, the link to bank 2, the measuring of individual cylinder temperatures, the massively reduced coolant flow in both cylinders (compared to most other cars) etc.

If the problem was general due to pure cold clearances - it would also influence GT3's, Turbos etc (especially as in those the piston expansion you would expect to be at least as high?

This is a bit like the IMS problem when we explained very early on that the bearing was basically too small and most alternatives will not be a permanent solution (and none seem to have been so far as our repairs have been analysed to other versions that have failed and which Porsche eventually confirmed by fitting a larger bearing that sorted the weakness).

We have no vested interest in any solution being right or wrong but we do analyse things through test results and scientific analysis and our explanation fits far more parameters, experiences and ticks more boxes than that is simply a problem of cold weather clearances.

The problem with Lokasil seems to be that the silicon particles are not as securely embedded in the alloy matrix as they are with Alusil (and of course there are no lose particles to fall out in Nikasil).

After many thousands of miles and years in Alusil you can see the difference where particles have eventually changed the surface but the ferrous coated pistons with more than twice the surface hardness of piston coating (compared to plastic) and bonded better to the piston surface and each other (through electroplating) resist damage by resisting the pieces cutting into the piston face.

The silicon particles do not (IMHO) fall out because of the thrust loads applied (and this may explain some confusion that I perhaps should have cleared up earlier). When the bore is machined and honed - some fall out then, others are cut on the faces and others are just under the surface of the matrix.

The particles that remain at the surface are either fully embedded (with a dove tail like retention of the larger part) or are already extremely small and not held in by physical matrix components but just by the bonding and are of a shape ready to fall out if the bonding fails.

The process of pushing against the particles may indeed loosen them somewhat but it is more likely the piston ring edges that catch them and loosen them until they become detached (and piston rings have no way of exerting more pressure on the thrust face than anywhere else).

IMHO it is only after the particles become detached that the problems start.

If the oil film is thicker than the particle size there is a good chance that they will find their way out before causing too much wear on the plastic piston coating face but this is where the "thrust face" comes into play because it obviously squeezes the oil film thinner than the other side of the piston and this reduces the thickness and allows the particles to interfere more with the piston coating.

The higher the thrust face load and the hotter the oil just there - the thinner that film will be and therefore the incidence of wear and tear to the plastic coating will be higher.

It is this that makes the temperature of the top of the cylinder in bank 2 so important as it directly influences the film oil thickness where the highest loads are.


I cannot imagine any reason why the particles should fall out because the piston has grown too big unless it affected both sides of the cylinder bore equally and even if it did I would expect the result to be on both sides not one.

Furthermore the oil film would be even thicker if the ambient temperature was sufficient to cause clearance problems.

Fitting a LTT will help (because although the coolant is cooler it at least opens the thermostat sooner and maintains better flow).

You need to look at a lot of issues to zone in on causes and things like the weird slot reducing the coolant flow into the cylinder blocks is something my explanation also considers whereas if the general clearances were the problem - the fact that the cylinders run hotter as a result should actually help keep clearances up.

IMHO blanking off the radiators surface area for such extreme conditions (or doing the equivalent automatically with phased set thermostats) would be a better way to avoid problems but overall - I expect Lokasil to release too many silicon particles for the plastic piston coating to survive for long enough to provide a reliable long term solution - and the change back to Alusil seems to support this argument.

I do accept however that the problems these engines create are extremely difficult to analyse and understand and involve a lot of different possible explanations and solutions and this is bound to result in differences in opinion that I suppose at least makes interesting reading!

I have not had a chance to think out why Boxster 3.4's appear to be less prone except one thought. It is extremely uncomfortable driving a cabrio with the roof down at high speed and in the UK - in general - I have found that people that buy canriolets - do so more for the pleasure of driving with the top down than flat out whereas I would expect buyers of hard top versions to be more aggressive (on average).

Perhaps something like this explains the apparent anomaly?

Baz

hartech

1,929 posts

216 months

Monday 30th March 2015
quotequote all
I am not so sure that there were any changes in the engines - cannot find any evidence of changes between models - so perhaps the older they are the more mileage they cover and the more worn the piston coatings and the more likely they are to score as a result. Perhaps also Boxsters tend to do less mileage (Sunday cars?).

The important point to work from is that the bore scoring is caused by lose particles of silicon breaking lose from the matrix and after that getting trapped between the piston and the bore.

Metal matrix composites (which is what Lokasil is most like) have a tendency to creep and this instability may make them more likely to loosen silicon particles earlier?

Baz

Edited by hartech on Monday 30th March 20:05

andyjohn4949

17 posts

118 months

Sunday 12th April 2015
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Hi - I was paranoid when I read all about 997.1 engine problems. Mine (2007 4s cab) has gone 45000 miles. Uses some oil (1000km per liter) but had engine checked and no scoring and compression good. Goes great.