Akers Porsche PPI - **997 issues**

so i've been spending a lot of time at my favorite porsche shop "akers porsche" here in seattle about 6 blocks from my home. i just sold my 2001 996 and the PPI was performed at their shop 2 days ago. whats really great about mark and denny aker is that they are so honest and knowledgable - they are air-cooled guru's who now morphed into water cooled geniuses - their other mechanic doug is one of the most knowledgable 996 mechanics on the west coast - he knows these cars like the back of his hand and is straightforward and to the point. during the PPI, akers found a few flaws with my car that i never noticed - i negotiated with the seller and we came to a fair sale price. the fact that akers is so neutral says a lot about their desire to remain focussed on the customer and their shops reputation - i've been friends with mark and denny akers for 25 years and they have always bent over backwards for their customers - more than i can say for other shops i have dealt with here and in california. during the past few days i was discussing my C4S purchase w/mark aker - (i know many of us 996 C2 owners want to step up to either a C4S/TT or 997 at some point in the future so we got on the topic of the 997). he was telling me that they (as well as some other shops) are beginning to have some 997's coming into the shop with excessive oil consumption - something like 2.5 qts per 600 miles - when the engines are broken down, the cylinder walls are scorched - he's discussed this issue with other shops and learned that it could be due to cars used in cold weather climates where the engine gets very cold/block contracts but aluminum pistons don't resulting in too tight of a tolerance. i found this interesting and also somewhat disturbing considering i'd like to step up to the 997 someday.

In the Boxster & Boxster S forum I believe Jake Raby has commented on this issue, arising mainly from cars from the far north (Canada) and the upper mid-west and perhaps the northeast. But this last winter JR reports cars coming in with this suspected problem from further south. Here's a link to the thread: https://rennlist.com/forums/boxster-...y-lifters.html

If you google "997 cylinder scoring", you'll be provided with plenty of reading material.

997.1 or.2 ?

I've heard of the same issues with the whole Porsche lineup, including Cayennes. The big factor here is the cars being driven in frigid temperatures.

997.1

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.1 There have been a few cases of cylinder scoring on .2's. Mike

Weren't the affected engines running forged pistons too, I say that not knowing if any or all 996/997 pistons are forged. Too little clearance between the piston and wall was the story.

I recently bought a 2002 3.6 case with a scored bore #6

When I was researching my car, I looked into the cylinder scoring issue. It seems to happen with M96 and 97 engines. The explanation for it is on about the same level of certainty that the various explanations for IMS failures, i.e. SWAGs based on anecdotal evidence and conjecture. If you google it Raby has a long discourse on why this happens in cars driven in colder climates. What he says makes sense as far as it goes but like everything Raby puts out on the internet it is to be taken with a grain of Salt. If Raby's explanation were the entire truth, every or at least a large percentage of Porsches driven in a cold climate and not stored in a climate controlled garage should develop scoring. But like the IMS failure, only a small percentage of even cars stored out in the cold during the winter ever develop scoring. Really the best explanation is that when you manufacture large numbers of engines over years that are made to really tight tolerances and are used by thousands of people every day in every imaginable circumstance, faults develop that can neither be fully explained nor predicted. Maybe the guy who machined the engine block was off his game that day and cut the cylinder just a fraction too small, maybe the forge was a little to hot the day the block was cast and it created a tiny flaw in the metal that only showed up years later. Who knows. The bottom line is that these are wonderfully reliable and nearly bullet proof cars, except for the very few that have catastrophic failures. I think you just have to accept the 5% or so chance your engine might go whenever you buy a 996 or 997.1 generation car. Not sure about the 997.2s.

It's not just Raby, a UK specialist, http://www.hartech.org/porsche_996_9...ers_guide.html goes into quite a bit of detail on the issue as well.

Mark Aker is a great guy. He has attended my M96/ M97 engine class and I spent time at his facility, and even went to see his Dad's car collection. In my class he learned about this deficiency and I am happy to see him applying what has learned at the shop. Lots of things lead to cylinder deficiencies, this year the cold winter has sent us into a spiral dealing with the issues. I generally only see this from the North East and upper Mid West, as well as Canada. This year we've seen it from as far south as Alabama and Texas. The common denominator was the cars being operated and cold started in very cold temperatures. I have literally been pulling words right out of caller's mouths when they start with their spiel on how the symptoms started. This issue is by far the hottest topic that we see here at the present, and at least here its bringing many more cars into the door than IMS bearing issues. Right now one car out of the 24 that we have here has failed due to an IMSB failure, but 9 of them are here due to cylinder scoring. Of those nine, 7 of them came from dealers or other shops after being mis- diagnosed as having bad lifters. Those people spent thousands on new lifters and the issue wasn't solved. Thats because it never was the issue and the diagnostician didn't know, what he didn't know.

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But IIRC Hartech blames the issue on the engine running too hot and advises among other things a low temp T-stat. And Hartech in spite of claiming thousands of cars are at risk offers to "insure" every one with an aftermarket warranty/service/repair policy.

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That Hartech material is really interesting reading. Again, his explanation makes sense but it is not the entire story since so many of the engines don't experience the problem. I do like their idea of a larger thermostat. I really can't see how running cooler could ever be bad for an engine and they make a good case that it would greatly reduce the risk of this happening.

The engines do run a few degrees hotter than optimum. However, the issues that we are finding are not related to over temperature conditions. The first time I saw this was from a Russian customer who lost an engine at 8,0000 miles, and another less than 18K later. Both were the same failures. The UK doesn't have a winter like North America, so the things that are observed are completely different. We NEVER see failed cylinders from Desert climates.

I have noticed that my car starts and runs noticeably better/smoother on cold starts when temps are above 40 or so.

Scored cylinder = the new IMS. Hopefully no one claims it's 5-10% failure rate this round.

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This isn't a new issue. The first time I saw it was well over a decade ago. Its just more prominent this year due to the crazy winter most of us had.

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This doesn't seem to make sense. If it is the cold weather that is causing the cylinder scoring and England does not have the frigid cold temps, then what is causing the cylinder scoring in England? Are you saying that only cars in hot climates avoid cylinder scoring?

Its all trend data. We know where the engines are failing and what the constants are. These are the things that I log as a researcher. There are two kinds of cylinder scoring, one is caused from cold temps and improper running clearance, the other is caused from deformations that the cylinder had since it was new. The first thing that always happens with any of these is a failure of the piston skirt coating. I can't explain all of the dynamics on a forum. All you can do is hope that it doesn't happen to you, as there is no preventive for it and nothing will help you dodge the bullet. Its all in luck, honestly.

There are two theories floated around. 1. Cold climates and really close tolerances with two different expansion rates( one being piston the othe the bore) causes bore scoring. When it's really cold they expand at different rates causing the oil to get squeezed out which makes the oil boundary layer to thin to protect the piston and bore. 2. Climate isn't even part of the theory but the car runs hotter on number 5&6 cylinder. If you have a heat soak from either sitting at idle for a while or a quick turn off and on for the engine such as stopping for gas, the heat soak causes a very thin boundary layer of oil or none at all. During this time, if you take off right then at high throttle input but low revs you can cause scoring. Both of this theories are actually good ones even if they do seem to contradict each other. However, the common denominator is close tolerances. Theory number 2 does say that in britan that it seems to happen more with cars with triptronics because if you don't floor it it takes off in second gear. That's why that theory includes high throttle input at low rpm and they recommend a low temp thermostat to help keep overall temps lower. Mike

Step right up folks living in four season climates. Reach your hand into this bag of colored rocks. If you draw a white rock you are treated to a durable engine. If you draw a black rock please be ready to fork over $20k or more for a replacement engine at some point. Enjoy your $100k Porsche! I know that's sarcastic, but is that the basic jist of what's happening? So, if you live in a cold climate should you not drive your car once the temp drops below a certain temp? This stuff makes me crazy. I want to enjoy my Porsche without worrying is today the day I draw the black rock.

LOL!!!!! Just DRIVE IT!

Everyone start selling their snow tires NOW and reinvest it in a car cover!!!!

My sarcasm aside, I get that any engine from any manufacturer will have some level of failures/significant issues. Perhaps it's just a biased sample set here on rennlist of folks who push their rides much harder than the average Porsche owner, and as such will be at the unfavorable end of the distribution when it comes to engine troubles. Guess only Porsche really knows those facts. I'll try and find comfort in the fact they actively sell winter wheel sets; so, they must have some level of confidence their cars are good for the conditions. Going to be 90 here today. Hopefully at that temp it's a good day for a drive.

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No, No, No...the lesson you should be taking away from this infomercial is: send your M96 engine to JR for a complete rebuild and you will not only be able to enjoy many years of trouble free motoring but you will also be able to sleep peacefully at night.

Do some searching for scored cylinders. It's just not Porsche having the problem. I believe that ethanol in our fuels is also causing premature wear. It burns hotter the gas.

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European manufacturers are all using similar piston and cylinder materials and technology. We are currently developing similar processes for AMG engines as well as 3 different models of BMW engine. Most recently I've heard of some Audi issues as well, so thats the next one to tackle.

There is another factor derived from cold conditions that I think Jake touched on in another thread which has been a common cause of cylinder scoring for years in some tightly toleranced cat converter equipped engines---raw fuel from the req'd rich mixture during warm up removing the oil film from piston/cylinder contact . Also, with an opposed flat cylinder configuration, the startup oil film would logically be concentrated at the lowest radius point of the cyl , whereas w/ a V or upright cyl config , a better chance of diametrical film coverage should exist . Flat 6 & 4 cyl aircraft motors utilize very high viscosity oil which may help this startup wear & as well is reqd for the greater tolerance variance associated w/ an air cooled motor . So, a simple suggestion to help alleviate this problem in your flat 6 p car might be to keep RPM's as low as possible during cold weather startups while going to thicker oil I feel would not be beneficial to lube some of the tiny passages . That's my 2 cents from 60+ DIY yrs w/ all types of 2 & 4 cycle motors . Bob 01 C4 31 Ford cp chp & ch, 302/350 40 ******, 302/350, IFS 38 Ford cp, 327/350, IFS 57 Belair 62 356B --long ago

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Absolutely.. Fuel is a solvent, you can use it to wash parts with.. Overly rich conditions that are used to light cats off early are the norm with these engines. People who allow the engine to idle to warm up keep the engine on cold start longer, since the second stage of cold start (not just started fuel) is coolant temperature referenced, not time based. Idling takes too long to heat soak the engine and too long for the CLT sensor to sense the temperature. Everything matters. When the planets align and it's your turn, it's no fun.

I would think your best not to use your 996 or 997 in bad, I.E. cold weather. These are summer cruisers, not snow plows. If you live in a more southerly climate you need not worry about the cylinder score issue but you should still be aware of the other 1001 MOF and CEF's.

Ford replaced a lot of engines in Tauruses in the late 80's for the same reason. Cyl scoring due to Temperature, expansion rate problums on their 3.0 engines in cold climates, I was doing 2 per day in my previous life.

Nice to see Ford step up and fix the problem with their cars. Porsche thinks it's too small so nobody will notice...

Me too in 1988 and 89. I worked at a Ford dealership in PA. That and the recall for the Escorts throwing oil into the carb. Spent about a year doing those. Then about another year later I quit the auto business.

Ford replaced the engines with full dressed units, everything but PS pump and alternator, I got to the point where I could almost do 2 completes per day, Between that and Escorts, Tempos with Ford ESP plans we were booking a lot of hours.