997 bore scoring found..

997 bore scoring found..

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Discussion

911Bill

Original Poster:

4 posts

113 months

Thursday 23rd October 2014
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Hi Guys,

I was just looking for some opinions and advice on a discovery I made over the weekend. With all this internet talk of 997 M97 engines eating themselves, starting at cylinder 6, I thought I'd get myself a camera and have a look.

I did discover what I was hoping I wouldn't..

Just some history.. I have owned the car for nearly 6 months having purchased it from a 911 specialist. It came with a generic warranty which I have now discovered doesn't actually cover cylinder liners for engines over 3000cc... Worthwhile for porsches then.
Anyway, as part of trying to prevent an internet horror story happening to me, straight after purchsing the car I fitted a 3rd radiator, low temp thermostat and changed the oil. The car has now only covered 27k miles, 1200 of which are mine. I let it warm up, cool down, I do drive it hard but always give it a cool down run where oil temp returns to 90degrees before shut down..

Now I have found this, I don't know what to think or feel about the car, I don't want to spend out on a rebuild, nor do I want to sell. I am hoping the damage occured before my ownership and can now be kept as it is through my caution.

According to posts I have found from specialists in this area, performing the radiator and low temp thermo upgrades along with regular oil changes can help.. I have done these, I am now thinking that my only option is to put thicker oil into the engine in an attempt to maximise my precautions. Currently it has 0/40 Mobil 1 but if I go for 5/50, or 10/60 as per my M3.. I am just not too sure or knowledgeable in this area.

If anyone can offer any genuine advice, that would be most appreciated.. I am just stunned that Porsche have not done anything about this!! It is ridiculous that such a problem exists on such a car, years of development and evolution were obviously spent doing other things!

Some pics via my camera below.. I think the pictures here make the scores look worse than they are due to the angle of the light, mainly is the last 2 pics. A video with better lighting showed the scores "in a better light".. I'll try and host that. Just to add, the scores were only found in cylinder 6 and look very light, they are on the bottom of the bore, 6 o clock. At the point of getting the images, the engine had not been started for 2 weeks, I'm not sure why the piston appears oily toward the edges in the 1st picture..

Thanks,
Bill






Edited by 911Bill on Thursday 23 October 15:06

PR36

341 posts

115 months

Thursday 23rd October 2014
quotequote all
I cant see the pics from work but would not assume the worst unless the bores were inspected and the issue confirmed by a reputable porsche indy workshop and based on other info you can provide eg oil consumption, does it smoke etc.

911Bill

Original Poster:

4 posts

113 months

Thursday 23rd October 2014
quotequote all
Thanks for your reply. smile

Just to add, on 2 occasions, I have noticed a small puff of white smoke on start up after a hard run which I think is normal as a friend with a 996 turbo and 997 carrera also do the same. I have not had to put any oil into the car within 1200 miles, I did an oil change 100 miles ago. Zero smoke at any other points (That I have noticed). The tailpipes become sooty at an expected rate and both evenly.

I wish Hartech were local, I may book it in with PARR or maybe even an OPC to have a professional opinion as you say.

Thanks again

PR36

341 posts

115 months

Thursday 23rd October 2014
quotequote all
I recently had my cayman s boroscoped as i needed the plugs changing and was always in the back of my mind worried about it. Came back all ok but i have heard stories of people being told they have scoring when actually the marks are normal, thats why i say get it checked by someone who knows there stuff. I had mine done at nine excellence, they were excellent.

Wozy68

5,387 posts

169 months

Thursday 23rd October 2014
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911Bill said:
Thanks for your reply. smile

Just to add, on 2 occasions, I have noticed a small puff of white smoke on start up after a hard run which I think is normal as a friend with a 996 turbo and 997 carrera also do the same. I have not had to put any oil into the car within 1200 miles, I did an oil change 100 miles ago. Zero smoke at any other points (That I have noticed). The tailpipes become sooty at an expected rate and both evenly.

I wish Hartech were local, I may book it in with PARR or maybe even an OPC to have a professional opinion as you say.

Thanks again
If I remember rightly, you get only one sooty pipe if bore scoring on a cylinder is a problem, which makes sense.
Doesn't seem that way with you. Are you sure your not worrying about something that isnt actually there yet?

Trev450

6,314 posts

171 months

Thursday 23rd October 2014
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Everything I've read about bore scoring and that is quite a bit, suggests that if it's going to be problematic then you are more than likely to have high oil consumption, often accompanied by a light tapping. Most cylinders will show some marking, but only an expert can really determine if they are the sign of actual scoring.

As already mentioned, have someone like Hartech examine them for a more conclusive analysis and hopefully peace of mind. In addition, try using some Millers Nanotech CFS 5W/40 which is what Hartech recommend and what I use in my CS.

PR36

341 posts

115 months

Thursday 23rd October 2014
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911bill if you live within a reasonable distance of parr or ne I would go there, I'm sure there perfectly capable of doing a boroscope and will have dealt with customers in a similar situation to yours many times before.

williaa68

1,527 posts

165 months

Thursday 23rd October 2014
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Does your car have a full OPC warranty? If so you could consider putting a porsche warranty on it - they don't check the bores!

mollytherocker

14,365 posts

208 months

Thursday 23rd October 2014
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Its not possible to determine if thats excessive scoring from those pictures. Well, not to me anyway.

Go to Hartech, they will give you a proper diagnosis. Given the potential cost implications, its worth a trip.

Ken Sington

3,958 posts

237 months

Friday 24th October 2014
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According the the newsletter from JZM which popped in this morning, their theory on the problem bore scoring is that it is related to the ethanol content in fuel. Hadn't seen that theory before.

911Bill

Original Poster:

4 posts

113 months

Friday 24th October 2014
quotequote all
Thank you for all of your replies, it's reassuring to hear your thoughts.

Ethanol is an interesting point, wasn't this an issue a few years back with Nikasil lined BMW engines? I always used Shell V power, I just tried a google search to find out it's enthanol content but I just came across mixed values. <0 - 5%..

I will contact Hartech and see if they recommend a visit, if not I will pop in somewhere local like 9E or PARR..

I am void a Porsche warranty as my car has some modifications, springs and an exhaust system, maybe I could reverse these to OEM and take out a warranty with an OPC. My car is a 2005, do they offer warranties to cars 10 years+ when that time comes? I tend to only do 2-3000 miles a year in the weekend car (this 997) so I am hoping I could get another 2-3 years use out of it before I sell, unless good 997 turbos hit £35k before then..The car does have a full OPC history.

I have since checked cylinder 5 and did see some lines but they were barely visible and look totally normal to me. The light on the camera tends to magnify the scores when it captures a still image.

Thanks again for your comments. I will contact Hartech and try and arrange a moment to visit a specialist.

Edited by 911Bill on Friday 24th October 13:04

Bennachie

1,090 posts

150 months

Friday 24th October 2014
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Looks like light normal scuffing to me rather than scored bores......

Trev450

6,314 posts

171 months

Friday 24th October 2014
quotequote all
Through their research, Hartech have found that it is the right bank and usually cylinder 6 that suffers the most from bore scoring. This being the case, how, then, does ethanol not have any negative impact on the other cylinders?

Gibbo205

3,527 posts

206 months

Friday 24th October 2014
quotequote all
Trev450 said:
Through their research, Hartech have found that it is the right bank and usually cylinder 6 that suffers the most from bore scoring. This being the case, how, then, does ethanol not have any negative impact on the other cylinders?
Cylinder 6 closest to the driver in a RHD car I assume? So also ways to access?

Trev450

6,314 posts

171 months

Saturday 25th October 2014
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Gibbo205 said:
Cylinder 6 closest to the driver in a RHD car I assume? So also ways to access?
That's right it is. Your second sentence has lost me though. confused

ChipsAndCheese

1,608 posts

163 months

Wednesday 5th November 2014
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Ken Sington said:
According the the newsletter from JZM which popped in this morning, their theory on the problem bore scoring is that it is related to the ethanol content in fuel. Hadn't seen that theory before.
I got that newsletter too, and was wondering whether anyone had posted about it on here for discussion. After all there are endless threads on alternative theories, it would be interesting to hear discussion from the experts about this theory. Here's the article on the newsletter in full.

JZM Newsletter said:
JZM Porsche Engine Rebuild Workshop: Scored Bores

The JZM Porsche engine rebuild workshop continues to produce wonderful, high quality Porsche engine rebuilds. Seen here is a 997 C2S engine undergoing rebuild for the well-known problem of cylinder wall damage, more commonly known as scored bores. This photo shows the perfect condition before re-assembly.
Various theories are put about for scored bores, most relating to engine operating temperature. Our experience across many engine strip and rebuild projects does not support that hypothesis.

JZM believes that rising ethanol content in fuel is the prime suspect. Plant derived ethanol (ethyl alcohol) is part of a global move to reduce carbon emissions. Modern pump petrol contains enthanol, which studies have proved will corrode aluminium under conditions of high temperature and pressure: such as in a combustion chamber. Once corrosion sets in, cylinder failure is inevitable.

Solving the problem of scored bores and preventing its recurrence is our priority when rebuilding Porsche engines. We insist on Nikasil protection on all our engine rebuilds, as Nikasil is impervious to enthanol. So far, we have achieved complete success when rebuilding engines using Nikasil coated cylinders.

We were recently visited by the first Porsche 997 ever to receive JZM Porsche Nikasil cylinders as part of an engine rebuild. Tens of thousands of miles later, it is still going strong, with zero oil consumption between services. Price up a cheap engine rebuild with associated risk versus doing it properly the JZM way, and there is no choice to be made: the proper job wins every time.

hornetrider

63,161 posts

204 months

Wednesday 5th November 2014
quotequote all
JZM Newsletter said:
JZM believes that rising ethanol content in fuel is the prime suspect. Plant derived ethanol (ethyl alcohol) is part of a global move to reduce carbon emissions. Modern pump petrol contains enthanol, which studies have proved will corrode aluminium under conditions of high temperature and pressure: such as in a combustion chamber. Once corrosion sets in, cylinder failure is inevitable.
So why isn't every car with an aluminium block dying with scored bores?

ras62

1,086 posts

155 months

Wednesday 5th November 2014
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Which begs the obvious question of why is the scoring more common on cylinders 5&6?

ras62

1,086 posts

155 months

Wednesday 5th November 2014
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So the increased temp in these cylinders is enough to induce corrosion in these cylinders only? Surely the appearance of corrosion and scoring are very different either to the naked eye or a microscope.

chowgar

15 posts

112 months

Tuesday 25th November 2014
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N
anonymous said:
[redacted]
Hello, I'm about to have my car in to Porsche for the same work as you. Did they charge you for any of the parts or labour. How about the engine oil? Thanks