FFS I have an engine problem *Confirmed Cylinder Crack*

2K said:

OP - Without wanting to detract from the excellent options listed above, thought to add some other info into the mix. On purchasing my late 996.1 I was advised on previous cracked head repair at 76K 2014. The invoice in the folder from Northway Porsche is for £3300, to repair crack in cylinder head bank 1-3. The sub con £460 Machine shop included. This price also included clutch kit £321, pas pipe £128 ac regas and head gasket £98 to list just a few. Anyway 30K on a pulling like a beast, we're blessed with hundreds of the best engineering shops on earth, these (usually) old boys masters offering a years warranty, but realistically sure they'll never see you again in their lifetime. Whichever way you go, good luck with it all.

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Cracked heads are common the early 996 engine, that is a totally different issue to cracks in the cylinder liner though, which is the problem here.

MC

Baz thanks for contributing to the thread, that's really useful info and as mine is a 3.6 it sounds like a 3.9 conversion is worth considering.

I'm looking to the future proof the engine and as this will become a bit of a project, I'll be looking to replace other parts and potentially increase performance too.

Have many people converted 996.2 to the 3.9? Would be interesting to speak to someone who has for first hand experience.

Thanks for the support from everyone and the useful insights.

Hi Leon,
3.9 is very new, Baz has been talking about it for a while as it's been in development. I think Alex tried a demo car, Baz may well have that for you to try. If so let us know!!!!

2K said:

OP - Without wanting to detract from the excellent options listed above, thought to add some other info into the mix. On purchasing my late 996.1 I was advised on previous cracked head repair at 76K 2014. The invoice in the folder from Northway Porsche is for £3300, to repair crack in cylinder head bank 1-3. The sub con £460 Machine shop included. This price also included clutch kit £321, pas pipe £128 ac regas and head gasket £98 to list just a few. Anyway 30K on a pulling like a beast, we're blessed with hundreds of the best engineering shops on earth, these (usually) old boys masters offering a years warranty, but realistically sure they'll never see you again in their lifetime. Whichever way you go, good luck with it all.

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I'm with you 2k.
If money is no object then an all singing, all dancing Hartech or Autofarm rebuild is the ideal solution, but if money was no object we wouldn't be driving 996s.

At the end of the day if my car goes bang I'll just sell it or go with a more cost effective solution. For the usage it gets and the low annual mileage I do I'll just want a repair that puts me back where I was.
If a Hartech rebuilt car goes the same and sounds the same as any other similar 996, then I'm not gonna pump £12k into a £15k car just for pub and forum bragging rights.

But that's just me and I always weigh up value for money and what one option offers vs another.
I just want a car to start, run, sound and go like it should. I don't really care if I can't say "I've spent £12k on my engine repairs".

For those that want the ultimate repair though there's no denying Hartech and Autofarm offer a good service. I'm not poo pooing them one bit.

The economics always come into play in such an issue, I can't see 986s getting rebuild unless the price is significantly different for them.
Most standard rebuilds are not 12k
I've have seen a hartech rebuild invoice when I was looking at a 997 which was around the 7.5k mark IIRC to fix borescore on one side so 3 liners plus rebuild and close deck other side too.

Maybe Baz can advise us the ballpark figure for 3.7/3.9 rebuild?

Marky911 said:

I'm with you 2k.
If money is no object then an all singing, all dancing Hartech or Autofarm rebuild is the ideal solution, but if money was no object we wouldn't be driving 996s.

At the end of the day if my car goes bang I'll just sell it or go with a more cost effective solution. For the usage it gets and the low annual mileage I do I'll just want a repair that puts me back where I was.
If a Hartech rebuilt car goes the same and sounds the same as any other similar 996, then I'm not gonna pump £12k into a £15k car just for pub and forum bragging rights.

But that's just me and I always weigh up value for money and what one option offers vs another.
I just want a car to start, run, sound and go like it should. I don't really care if I can't say "I've spent £12k on my engine repairs".

For those that want the ultimate repair though there's no denying Hartech and Autofarm offer a good service. I'm not poo pooing them one bit.

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With my north eastern upbringing, I'm with Marky on this one. There's always the new Porsche short motor as an option too, about 5k plus labour and any extras.

maldren said:

Marky911 said:

I'm with you 2k.
If money is no object then an all singing, all dancing Hartech or Autofarm rebuild is the ideal solution, but if money was no object we wouldn't be driving 996s.

At the end of the day if my car goes bang I'll just sell it or go with a more cost effective solution. For the usage it gets and the low annual mileage I do I'll just want a repair that puts me back where I was.
If a Hartech rebuilt car goes the same and sounds the same as any other similar 996, then I'm not gonna pump £12k into a £15k car just for pub and forum bragging rights.

But that's just me and I always weigh up value for money and what one option offers vs another.
I just want a car to start, run, sound and go like it should. I don't really care if I can't say "I've spent £12k on my engine repairs".

For those that want the ultimate repair though there's no denying Hartech and Autofarm offer a good service. I'm not poo pooing them one bit.

Click to expand...

With my north eastern upbringing, I'm with Marky on this one. There's always the new Porsche short motor as an option too, about 5k plus labour and any extras.

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Each to their own but it isn't as straight forward as you suggest.

There are many different angles to approach this from but if one finds oneself in the unfortunate position of an engine failure and needing a re-build the car is worth a great deal less.

The £15k car becomes say a £4k - £7k one and if, at the end of the exercise, a customer 'needs" a sportscar they need to either spend money fixing the one they have or sell it and then top up the funds to be able to buy another vehicle of similar standing.

Either way, it's a large expense and people have different views as to what direction to take.

Some choose to just fix what has gone wrong and in the case of a cracked cylinder this could theoretically be as little as £3000 + VAT (if someone brought us a long motor stripped of ancillaries and only wanted that 1 cylinder replacing and nothing else – which could be the case with the original poster of this thread).

We would then suggest betterment where a customer may want to take advantage of it being stripped and do the best job they could - all new liners, piston rings, crank bearings, timing chains, guide rails, later design 2006 onwards intermediate shaft, basic head overhauls etc would cost c.£7300 + VAT.

Others may choose to cherry pick between the 2 options.

Others may wish to go with a Porsche exchange short motor but they would still then have Lokasil open deck cylinders which isn't our preferred choice.

Others may wish to use the opportunity to make it a larger capacity engine and so on.

Some may choose to walk away from the car but if they want another 911 they may need to find a further £10k + to get a like for like vehicle pre-engine failure (that could still then fail again).

Obviously, each case is different but rather than talking about pumping £12k into a £15k car it would be more realistic to say 'my £15k car is now worth £5k (or whatever) because my engine's goosed and I can spend £5k (or whatever) fixing it to make it worth £15k again – I can then spend more money and carry out a better job if I want to reduce my likely long term running costs and I can make it even quicker whilst I'm at it !".

We can argue about the figures but my main point is that the car is worth considerably less when it has a problem.


Grant

I think these are wise comments Grant.

For me the deciding argument is that if your car is worth £5k with the goosed engine (and you find someone willing to take it on at that price), you need to spend £10k to get back into a £15K car - but the health of the mechanicals is a bit of an unknown entity.

For value for money, far better to spend the same £10k (often less) reapiring the initial failure, and while the engine is open, carry out a full refurbish of worn items and those components that need replacement. As most 996s have mileage around 100k miles, this work will be due.

That way, you have a repaired and fully refurbished engine, warranted, with the very real prospect of a further 100k miles happy motoring. You won't get that level of value for money from the purchase of a £15k 996 (unless the car has said work carried out on it!!)

Something else worth thinking about is the fact these engines can fail is probably a big part of the reason these cars are £15k rather than say £25k, so you could say the price of a rebuild is already built in!!? :dont know:

Yes, you could say that, only the rebuild ones are still not 25k. But yes there is the back Of The mind feeling of driving a ticking time bomb, more so with a 3.6.. Then theres the 3.4 with 360k on original engine so go figure..

I priced it in, knew that the engine might go boom before I bought the car.

asterix_the_gaul said:

Then theres the 3.4 with 360k on original engine so go figure..

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PPBB's engine rebuilt was at only 300k... :grin:

Fastlane said:

asterix_the_gaul said:

Then theres the 3.4 with 360k on original engine so go figure..

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PPBB's engine rebuilt was at only 300k... :grin:

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Wow - 300k Before a rebuild is impressive but I think it's more of a freak occurrence rather than the norm – time will tell.

A while ago I posted a view which I strongly believe in, but I was accused of scare-mongering etc.

I still maintain that view but since it was so negatively received by some I've only since shared it with people during conversation but I'll outline the basics again (let me put my helmet on first ready for the backlash !).

A few facts:

All engines eventually wear out.

Proper sports cars are usually light weight and powerful so their engines are usually light weight and chuck out a lot of power for their physical size – in simple terms each cubic centimetre of metal generally is stressed more than/needs to work lot harder than a less powerful heavier engine.

Most sports car owners buy them to drive reasonably quickly.

Most of the M96/97 engines are between 10 and 20 years old.

M96/97 engines have 5 well documented classic weak spots with some being more common than others.



Now moving onto my view – the failure of some of the weak spots seem to be rather random in nature, others are progressive (i.e. the more the car is used the closer these areas get to their failure points) & there could be a combination of the 2.

Thinking more of the progressives, the clear cut ones are cylinders cracking and crank bearings wearing out and failing.

If a cylinder cracks I can't recall seeing one which has had a massive knock on effect turning it into a complete disaster – a new cylinder is usually needed and it makes sense to strengthen the others at the same time. A re-build is needed but it isn't catastrophic.

Crank shaft bearing failure, on the other hand, is a potential nightmare. First of all, the cranks are only hardened on the very outside so as soon as this layer is penetrated you hit soft metal which means that they need re-hardening after grinding which is a little hit and miss. Oversize crank bearings are also expensive so currently, weighing up all factors, the easiest and usually most cost-effective solution is a good used crank but they're starting to get thin on the ground. For some models they're becoming impossible to find and new ones are over £2k + VAT.

Secondly, debris from the failure usually damages the oil pumps and can get into the cylinders which potentially wipes out the pistons & cylinders.

In the worst cases the connecting rod bolts or rods themselves break leading to the internals being smashed rendering the bottom end totally scrap and sometimes wiping out the heads in the process.

So, a crank bearing failure is the worst and most expensive failure we usually see.

In normal road cars we tend to find crank bearings appear quite worn from 60k miles onwards with failures occurring from around 100k miles upwards. There will always be variances and the driving style can certainly play a part as the rear main bearing takes a lot of load when driving a manual car hard. Some still look terrific at 80k !

What we don't know is how many cars just keep going beyond the 100k without being a problem and no-one really does. Forum members are only a small sample of Porsche owners so whilst I expect to get responses of 'mines done 110 k and hasn't gone wrong" there are plenty that have gone wrong and lots that will around that mileage which would/will have been a lot cheaper to sort out if they were pulled apart pre-disaster. We also don't know how close the running 110k engine is to failure.

There is certainly a case for carrying a pre-emptive re-build at a certain point – this isn't salesmanship, scare-mongering etc. It's just a well-intentioned view from someone who's at the coal face.

Grant

Also - although I am listed as the contributor - you will notice some of the posts are written by Grant - not me!

I deal with technical issues whereas Grant has to deal with customers with engine problems and helping them make decisions.

We usually agree on everything - as we do on this subject - but those of you who seem to have some big problem with anyone technical offering advice from the basis of their honest experience (and who has dealt with hundreds of failures and rebuilds over many years) are doing us an injustice to suggest we make things up for salesmanship or scaremongering.


It is not our fault these engines go wrong and we would not have the reputation we have if we did not provide honest and balanced views on things.


When - well over 10 years ago - we invested in machinery, development, tooling, test cars etc we did so because we believed (for good technical reasons) that the engines would become a bigger problem than they were at the time and we were right and many have benefitted as a result.

When we explained why some versions cracked cylinders and at what amount of ovality - we were right and when we got to the bottom of the problem of scoring we were right again.

However we don't know if there are many more cars that have already covered 200 or 300K without a problem than there are engines that have failed already - all we know is that the most common failure mileages are around 100K and more and more include crankshaft failure and unnecessary added expense. Furthermore when we measure internals - they all follow a very similar pattern of wear - so those that last longer must have something unusual about them - either a coincidental top original material quality or tolerance mix or very sympathetic drivers using good practice and maintenance.


What we cannot do is please everyone (no one ever can) so by all means give your opinion about pre-emptive rebuilds and why but in the same way I do not accuse those that disagree with us about the advice of doing so out of spite, jealousy or because they are in competition with us - but because their position is honestly described - please kindly keep your opinions objective and return the compliment as this will help others make their own minds up better than becoming overly emotionally involved in an argument that at the end of the day is simply a choice (and at least we provide a choice that otherwise may not have been available to those that appreciate it).


Baz

Perhaps Baz or Grant could answer this?

If one was to have a pre-emptive rebuild on a 100,000 ish mileage engine would you expect to be able to reround and strenghten the cylinders and end up with a long life engine? Lets say you would have the latest design IMS etc.

Would the cylinders then stay round or would you expect them to oval again?