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clint1093

Original Poster:

11 posts

27 months

[news] 
Friday 1st June 2012 quote quote all
hartech said:
Stop worrying the 2.7 is unlikely to score bores.

The bore diameter is smaller than a 3.2, 3.4, 3.6 or 3.8 and the cylinder casting is different so the amount of coolant surounding the cylinder is greater while the loads on the smaller piston are much less - so overall (as it produces less torque).

It is difficult to know exactly under what conditions a score starts (as it happens in a few seconds) - except that it is a known phenomenon at low revs and high torque.

We get slightly more tiptronics though for repair than manuals - so if more manuals were sold (don't know the figures) that would support this opinion because the tiptronic starts off from standstill in second of 5 gears and the 3.6 and particularly the 3.8 produce massive torque at very low revs (which starting off in second occurs at very low revs compared to someone driving a manual from 1st).

So I think you are safe to ignore any worries and be glad you chose a more reliable version.

Baz



Thanks for all the infomation, I am happy with what hartech post as they seem to be the people in the know.
Would still be interesting if someone has had this problem on their 2.7, if no one replies then to me it seems the problem is with the 3.4?

V8KSN

2,303 posts

68 months

[news] 
Friday 1st June 2012 quote quote all
Baz, please could you answer the following question for me?

So, say you are on a quick run using high revs and power and then park up and stop, should you let the engine tick over before switching it off or should you just turn it off even if the oil temp is over 100?

Rockster

1,100 posts

44 months

[news] 
Friday 1st June 2012 quote quote all
mollytherocker said:
You need the 3 point plan!

1 - Get the Hartech low temp thermostat fitted;
2 - Follow Barry Harts advice on not doing fast starts when the engine is hot;
3 - Enjoy!

MTR
That is the most laughable advice ever.

A low temp t-stat fitted to I guess address some rumored overheating of one cylinder? It will be interesting to see what comes of this over time if anyone takes this advice.

One outcome. I have some good news and some bad news. The good news is one cylinder is not scored. The bad news is other 5 are worn out from running too cold a t-stat.

And what to do about new cars under warranty? Replace the factory t-stat now and possibly void the new car warranty or wait until after the car's warranty expires? And to avoid this horrible scoring I guess the owner just parks the car so the warranty expires on time. then after the mod drives the car. Talk about delayed gratification.

And then for cars no longer under warranty and for owners who were not aware of the need to do no fast starts with the engine hot or got this knowledge too late? What about these drivers? I guess the magic of a low temp t-stat will somehow undo all the scoring that has occurred while running that stock high temp t-stat and being driven by an owner who was unaware during this time he was not supposed to engage in fast starts with the engine hot?

And what is too hot? How is someone to know? Maybe there's a market for a coolant sensor connected to a warning light that changes color as the coolant temp changes. Blue when cold, green when just right, yellow when getting warm and red when too hot. Flashing red and oh oh the engine's toast.

Oh the joy of owning a sports car that one can't drive like a sports car.

God only knows what this kind of I don't what will have on the used Cayman market.

One more tool to add to the kit when shopping a used Cayman: Thermostat; to use to take the car's coolant temp after test ride/drive to determine which side of the t-stat fence the owner is on.

Last but not least: Enjoy? Enjoy a car that supposedly needs this kind of straight from the factory modification and pampering? And live in fear? Given this I would enjoy such a car about as much as I would a root canal.

Sincerely,

Rockster.

hartech

1,598 posts

101 months

[news] 
Friday 1st June 2012 quote quote all
Well it is always best to feed into high speed driving gradually if you can and have a cooling down stage - again - if you can - any other advice will only comr from an idiot.

I repeat - for the sake of an American rockster that the advice others have attributed to ne is for the Cayman S, 3.6 and 3.8 and perhaps he could tell the owners who have bore scoring what they did wrong to cause it as it obviously is their fault and not the car! Sarcastic - yes - but what nonsense. Easy to criticise others but where is the advice to help - as we try to provide?

Baz

Rotty

125 posts

66 months

[news] 
Saturday 2nd June 2012 quote quote all
what is the cost of having the low temp thermostat fitted ?
Advertisement

cvega

195 posts

43 months

[news] 
Thursday 16th August 2012 quote quote all
wait, so this issue is not covered by OPC warranty?

mollytherocker

10,801 posts

93 months

[news] 
Thursday 16th August 2012 quote quote all
cvega said:
wait, so this issue is not covered by OPC warranty?
Yes, if the car is in warranty.

MTR

hartech

1,598 posts

101 months

[news] 
Thursday 16th August 2012 quote quote all
There are a variety of reasons for bore scoring.

It occurs when the oil film between the piston and the cylinder bore cannot keep the 2 pieces separated by a strong enough oil film barrier after which friction increases and with it the temperature and with it the oil gets hotter so its viscosity falls and the vicious circle continues until the piston face melts momentarily and pieces solidify again and dig into the cylinder bore material.

This in turn releases sharper crystals of silicon to wear more quickly into the piston face.

Some different cylinder bore materials (Alusil and Nikasil) could prevent this but are more expensive (as used on older air cooled Porsche's, 944's and 968's and GT3's and turbos manufactured when Porsche were going bust). A more expensive piston coating could also prevent this problem (and was used in earlier models without the problem).

Running the cylinders cooler would also help keep the oil viscosity higher.

A change to the cylinder head gasket design to enable it to fit both sides instead of needing 2 different ones compromised the coolant balance in the Cayman S. 3/6 and 3.8 engines - this did not help.

Changing all four above would totally resolve the problem but in production would cost much more. What is the expression ow - "you pays your money and takes your chances"?

There is not much can be done to a standard engine unless you have it in pieces - to help - except try and run it a little cooler and avoid high torque at low revs (when most cylinder scuffing occurs) or avoid high torque after the engine has been sitting cooking while the revs are low say during a brief stop when the oil between the cylinders and pistons is at its hottest. Change oil more regualarly and use thivker oil as the engine wears over time.

If you have a brain that can think a problem out for itself just consider that all the engines that fail have the standard thermostat fitted - smaller versions of the engine with less torque but the same technology rarely fail, those engines with more space for the coolant do not fail, those with the original head gasket (that is paired) do not fail.

I suppose forming a correlation over those changes is too difficult for some - strange that those very same people think they are the resident experts (although they don't repair several engines each week).

There are several new developments of our own under test to add to the impressive array of solutions we put into improving the engines as we rebuild them - but I am worried not that they may not work as I havn't consulted our American expert yet (probably just as well eh)? Funny really that Porsche make em and some fail - I fix em and they don't! but Porsche can do no wrong and I apparently don't know what I am doing LOL.

More soon in more detail in one of the topical Porsche magazines.

Baz

nick997

573 posts

92 months

[news] 
Thursday 16th August 2012 quote quote all
2.7 Cayman or Boxster from 2007 onwards sound like great buys, Turbo's and GT's excluded. No bore scoring, less chance of an IMS, no D chunking, would that be a fair comment or wishful thinking from a previous owner with a (very) itchy scratch that needs to be addressed.

Chrisp5782

381 posts

22 months

[news] 
Monday 8th October 2012 quote quote all
nick997 said:
2.7 Cayman or Boxster from 2007 onwards sound like great buys, Turbo's and GT's excluded. No bore scoring, less chance of an IMS, no D chunking, would that be a fair comment or wishful thinking from a previous owner with a (very) itchy scratch that needs to be addressed.
I know this thread is a little old now but.....I think you've pretty much hit the nail on the head there.

I had a 2002 2.7 Boxster and, because I was flapping, had the LN Engineering IMS upgrade done at around 60,000 miles. The bearing that was removed was in perfect (thats right PERFECT) condition with absolutely no signs of wear.

When I bought my 2007 2.7 Cayman I rang Autofarm for advice ( I trust them completely) and Josh said not to worry about IMS as the chance of failure after MY '06 was minimal, as was the risk of scoring, very much what Hartech say.

My Cayman is used (read driven enthusiastically) on a daily basis and has covered nearly 60.000 miles. It gets serviced every 10.000 miles and is enjoyed as Porsche intended.

Whilst there are failures ( I understand mainly in 986/996 and some very early 997/987's )it would seem that statistically you're better off with a 2.7 Cayman/Boxster from 2006 onwards, I'm more than happy to listen to others on this though?

I read the US based forums and I'm tired of reading this "ticking time bomb" attitude from many people. Clarification of the situation is never going to be forthcoming from Porsche AG so we should put our faith in those that have experience of rebuilding engines and engineering solutions to some of the M96/M97 engine issues - thats my take on it anyways.


Tom 911V

74 posts

24 months

[news] 
Monday 8th October 2012 quote quote all
Hi Clint,

Although more prevalent on the 3.4 I have seen and rejected three 2.7 Caymans with scored bores during the course of the last 12 months. x2 were 2007 cars the other a 2008. On all three cars the bores were scoped for clarification of our initial visual suspicions i.e excessive sooting of exhaust and oil staining + oil spotting to the rear bumper of the car ( all cars were dry underneath with no engine/gearbox leaks ). For perspective I see more 3.4's with the same issues and for further perspective I see significantly more Caymans without problems than with them. The liklihood of you having an issue is very slim indeed. If you want any further advice PM me.

Tom 911 Virgin

ScienceTeacher

174 posts

69 months

[news] 
Monday 8th October 2012 quote quote all
Rockster said:
That is the most laughable advice ever.

A low temp t-stat fitted to I guess address some rumored overheating of one cylinder? It will be interesting to see what comes of this over time if anyone takes this advice.

One outcome. I have some good news and some bad news. The good news is one cylinder is not scored. The bad news is other 5 are worn out from running too cold a t-stat.

And what to do about new cars under warranty? Replace the factory t-stat now and possibly void the new car warranty or wait until after the car's warranty expires? And to avoid this horrible scoring I guess the owner just parks the car so the warranty expires on time. then after the mod drives the car. Talk about delayed gratification.

And then for cars no longer under warranty and for owners who were not aware of the need to do no fast starts with the engine hot or got this knowledge too late? What about these drivers? I guess the magic of a low temp t-stat will somehow undo all the scoring that has occurred while running that stock high temp t-stat and being driven by an owner who was unaware during this time he was not supposed to engage in fast starts with the engine hot?

And what is too hot? How is someone to know? Maybe there's a market for a coolant sensor connected to a warning light that changes color as the coolant temp changes. Blue when cold, green when just right, yellow when getting warm and red when too hot. Flashing red and oh oh the engine's toast.

Oh the joy of owning a sports car that one can't drive like a sports car.

God only knows what this kind of I don't what will have on the used Cayman market.

One more tool to add to the kit when shopping a used Cayman: Thermostat; to use to take the car's coolant temp after test ride/drive to determine which side of the t-stat fence the owner is on.

Last but not least: Enjoy? Enjoy a car that supposedly needs this kind of straight from the factory modification and pampering? And live in fear? Given this I would enjoy such a car about as much as I would a root canal.

Sincerely,

Rockster.
It is my understanding that Porsche themselves now fit lower temp thermostats to all their cars and have done to GT and racing models all along.

itsybitsy

1,544 posts

69 months

[news] 
Monday 8th October 2012 quote quote all
this is true just look at one of the latest brochures,all dfi engines now have improved cooling

Rockster

1,100 posts

44 months

[news] 
Tuesday 9th October 2012 quote quote all
itsybitsy said:
this is true just look at one of the latest brochures,all dfi engines now have improved cooling
Browsing through Porsche's technology site I find mention that there have been cooling improvements but this is touted by Porsche every model year since at least when I bought my 02 Boxster. The 03 models received improved cooling by aerodynamic improvements to direct more air through the radiators.

Subsequent models years have similar mention of cooling improvements.

I see no specific mention low temperature thermostat has been used. This doesn't lower operating temps it just delays warmup which would make the engine do poorly in fuel mileage testing and emissions testing. CO2 emissions would go up and in fact both have gotten better even as engine output has risen some.

Recently I've been digging into the 997 Turbo and my tech reference -- courtesy of a tech -- for the 997 Turbo doesn't mention a low temp t-stat but it covers in detail other changes to the engine over that of the 996 Turbo.

In the past when I asked about this scoring problem to which the low temp t-stat "solution" is intended to address -- which apparently is bad enough to warrant a low temp t-stat and having the driver observe silly precautions and restrictions that would have one enjoying a ride on a lawn mower more than in his Porsche and yet doesn't so far as I have been able to learn result in engine misfires which are clear indication of under (or over) performing cylinders -- the idea was dismissed as being a bad solution for a non-existing problem.

But I will be visiting some dealerships soon and will speak with the techs about any issues and any word on the fitting of low temp t-stats to the newer engines. Maybe in the intervening months something new has come up.

Sincerely,

Rockster.

Trev450

3,408 posts

56 months

[news] 
Tuesday 9th October 2012 quote quote all
Would'nt the improved cooling on the DFI engine come as a result of going to a closed deck system?

R2D3

42 posts

71 months

[news] 
Tuesday 9th October 2012 quote quote all
Hartech of Bolton have been mentioned a couple of times. There is a very comprehensive article on their web site detailing this problem of bore scoring and ways to avoid it. Its well worth a read. Its a bit like reading one of Steven Hawkings books for the first time; but certainly worth the effort.

Jaged

3,501 posts

78 months

[news] 
Saturday 3rd November 2012 quote quote all
OT a bit.

I recently got an 03 Boxster S TIP and was telling a fella at work about these problems.
He told his friend who had recently bought a used low mile Carrera from a Porsche dealer.

They then found oil on left exhaust and short story is the dealer has agreed a Hartech rebuild (might even be in the shop now).

Fingers crossed on my Boxster, but being an Engineer myself, I tend to treat engines sympathetically.


mollytherocker

10,801 posts

93 months

[news] 
Saturday 3rd November 2012 quote quote all
Jaged said:
OT a bit.

I recently got an 03 Boxster S TIP and was telling a fella at work about these problems.
He told his friend who had recently bought a used low mile Carrera from a Porsche dealer.

They then found oil on left exhaust and short story is the dealer has agreed a Hartech rebuild (might even be in the shop now).

Fingers crossed on my Boxster, but being an Engineer myself, I tend to treat engines sympathetically.
Just to be clear, are you suggesting that an opc is funding a Hartech rebuild under warranty?

Jaged

3,501 posts

78 months

[news] 
Sunday 4th November 2012 quote quote all
mollytherocker said:
Just to be clear, are you suggesting that an opc is funding a Hartech rebuild under warranty?
That is what he told me.

uknick

368 posts

68 months

[news] 
Sunday 4th November 2012 quote quote all
Jaged said:
OT a bit.

I recently got an 03 Boxster S TIP and was telling a fella at work about these problems.
He told his friend who had recently bought a used low mile Carrera from a Porsche dealer.

They then found oil on left exhaust and short story is the dealer has agreed a Hartech rebuild (might even be in the shop now).

Fingers crossed on my Boxster, but being an Engineer myself, I tend to treat engines sympathetically.
mmmmmm. A friend told a friend who told a friend a Porsche dealer is paying an independent to rebuild a Porsche engine under warranty whistle
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