View Poll Results: Poll: Have you had bore scoring on your 997.1 or 997.2 engine?
Yes, 997.1 (05-08 MY)
138
14.44%
Yes, 997.2 (09-12 MY)
17
1.78%
No, 997.1 (05-08 MY)
512
53.56%
No, 997.2 (09-12 MY)
289
30.23%
Voters: 956. You may not vote on this poll
Poll: Scored cylinder failure for your 997, Y or N? tell us (yr, 997.1 or 997.2)
09-05-2017, 11:55 AM
#106
Note that all the people saying "no bore scoring" most likely really mean that they have not exhibited external symptoms yet (if they ever will that is). My point is that without a proper borescope you just don't know, and even then you may not be able to diagnose 100% (according to the master Jake R).
Has anyone with reasonable mileage scoped their car and found absolutely no signs of wear? I feel like some wear is inevitable with a boxer engine.
09-05-2017, 03:23 PM
#107
It burns about a liter in 4k/miles. Motul 8100 5-40.
09-12-2017, 09:18 AM
#109
Just looked at the statistics you have provided and I think using the whole number of both types of car to assess the percentages is misleading.
From your own figures for the 997.1 the failure percentage is 15% (one in every 6 and a half cars) and for the 997.2 it is 2% (one in every 50).
This makes the 997/1 15 times more likely to score than the 997.2.
It is also interesting to note that many 997.1 cars are driving OK, no oil consumption problems nor signs of a problem but have actually already started scoring (about one in 3 we find) - but this I usually only damaging one side of the piston (the thrust side) and usually only on bank 2 and will probably only deteriorate very slowly over more than 10K, whereas the usual scoring mode of a 997.2 is perfectly Ok for a long time then a full seizure on both sides of the piston and is usually terminal when it occurs and they are much younger and on average have covered less miles - still far less likely to occur but time will alter the figures.
The 997.1 failures are more related to piston coating loss and the deterioration of the silicon particle bonding in the cylinders releasing particles to interfere with the piston coating whereas the evidence we have so far uncovered suggests that the 997.2 failures are more associated with a very slow process of the bores in some cylinders shrinking in diameter in the thrust direction and eventually pinching the pistons (especially when driving with too much power while the whole engine is not fully warmed up).
This means that 997.1 cars are probably really failing at a higher percentage than the present 15% and 997.2 will probably increase in failure numbers more rapidly as mileages and hot cold heat cycles increase promoting shrinkage.
Baz
From your own figures for the 997.1 the failure percentage is 15% (one in every 6 and a half cars) and for the 997.2 it is 2% (one in every 50).
This makes the 997/1 15 times more likely to score than the 997.2.
It is also interesting to note that many 997.1 cars are driving OK, no oil consumption problems nor signs of a problem but have actually already started scoring (about one in 3 we find) - but this I usually only damaging one side of the piston (the thrust side) and usually only on bank 2 and will probably only deteriorate very slowly over more than 10K, whereas the usual scoring mode of a 997.2 is perfectly Ok for a long time then a full seizure on both sides of the piston and is usually terminal when it occurs and they are much younger and on average have covered less miles - still far less likely to occur but time will alter the figures.
The 997.1 failures are more related to piston coating loss and the deterioration of the silicon particle bonding in the cylinders releasing particles to interfere with the piston coating whereas the evidence we have so far uncovered suggests that the 997.2 failures are more associated with a very slow process of the bores in some cylinders shrinking in diameter in the thrust direction and eventually pinching the pistons (especially when driving with too much power while the whole engine is not fully warmed up).
This means that 997.1 cars are probably really failing at a higher percentage than the present 15% and 997.2 will probably increase in failure numbers more rapidly as mileages and hot cold heat cycles increase promoting shrinkage.
Baz
09-21-2017, 10:17 PM
#111
quick update, my 997.1 started ticking in the 80km in Southern Ontario. this mid year i passed emsissions, and now today crossed over 120km. it is much louder but it does not seem to want to die.
only change is running liquid moly 10W60 year round and burns about 1 litre per 1,000km or less.
only change is running liquid moly 10W60 year round and burns about 1 litre per 1,000km or less.
11-27-2017, 01:44 PM
#112
Well unfortunately suspicions were confirmed..
120km
997.1 (M96.5)
scored bores on Bank#2 Cyl 4 and 5. Cyl 6 looks ok still.
Original complaint was higher than normal oil consumption at ~ 1L/900km (although still within Porsche specs). Smoking at cold start (occasionally depending on what angle I parked at)
Car still runs fine, bank 2 (LH side) tail pipe does look blacker than the other. Plugs looked ok, but cyl4 and 5 were oily (not sure how old they are). Oil filter was inspected at the last change and was perfect.
Looks like I'll be planning a bottom end build. Maybe 3.8? Stay tuned..
120km
997.1 (M96.5)
scored bores on Bank#2 Cyl 4 and 5. Cyl 6 looks ok still.
Original complaint was higher than normal oil consumption at ~ 1L/900km (although still within Porsche specs). Smoking at cold start (occasionally depending on what angle I parked at)
Car still runs fine, bank 2 (LH side) tail pipe does look blacker than the other. Plugs looked ok, but cyl4 and 5 were oily (not sure how old they are). Oil filter was inspected at the last change and was perfect.
Looks like I'll be planning a bottom end build. Maybe 3.8? Stay tuned..
01-19-2018, 04:37 PM
#115
4th Gear
Join Date: Dec 2011
Location: Vancouver, BC
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2006 C4S with 77000km (48000mi)
Just had the engine scope and found scoring in all the cylinder bore. One had a bit of oil seepage.
In the 3000km we've had it show no oil consumption at all and no startup smoke. No trace of burnt oil on the tailpipe.
Had 16 ignitions at Range 6(!) but that was at 600hrs. 1900 on it now. I don't believe that is an issue at this time.
What was recommended and done were to go to a lower temp thermostat and a higher zinc content oil Motul 5w-40 X-cess (not shilling just stating the facts)
I'll keep everyone updated for any changes. Fingers crossed
Just had the engine scope and found scoring in all the cylinder bore. One had a bit of oil seepage.
In the 3000km we've had it show no oil consumption at all and no startup smoke. No trace of burnt oil on the tailpipe.
Had 16 ignitions at Range 6(!) but that was at 600hrs. 1900 on it now. I don't believe that is an issue at this time.
What was recommended and done were to go to a lower temp thermostat and a higher zinc content oil Motul 5w-40 X-cess (not shilling just stating the facts)
I'll keep everyone updated for any changes. Fingers crossed
01-20-2018, 10:50 AM
#116
Rennlist Member
2006 C2S, 6spd, 60k miles. car is all stock, maintenance records are spoty at best. but over rev is very clean, 0 in the 4-6.
Car spent 06-08 in South Carolina, then 2008 to present in the Northern VA/DC area.
Waiting to vote until she comes back from the shop with bore scope results. Purchased the car about a month ago, the weekend I picked it up took it for a bout 200 mile drive into the hills, 100 miles away from home got a blinking low oil message (in my excitement over a new car/my first Porsche I didn't check the oil level before I left, kicking myself hard now) nursed it a few miles to an auto parts store and it took approx 1.6 qts to bring it up to full, drove home conservatively. Oil and filter change the next day, no visible metal in the filter or in the oil, New Mann filter and mobile 1 0w-40. I have driven about 500 miles since the oil change, I'm getting black soot on the driver side tail pipe, but no CEL, and no noticeable oil consumption (I would give anything for a normal dipstick).
Did I just make a $25K mistake in my haste? Also, would switching to a heavier weight oil make sense at this point?
Assuming I have some scoring in at least 3 cylinders, and no audible ticking. I'd like to get another 10-15k out of it before rebuilding the motor from a life/finances standpoint. Am I past that point, and a rebuild is necessary immediately, and to keep driving it will grenade the motor?
Sorry for kind of thread jacking, I'll gladly take off line.
Car spent 06-08 in South Carolina, then 2008 to present in the Northern VA/DC area.
Waiting to vote until she comes back from the shop with bore scope results. Purchased the car about a month ago, the weekend I picked it up took it for a bout 200 mile drive into the hills, 100 miles away from home got a blinking low oil message (in my excitement over a new car/my first Porsche I didn't check the oil level before I left, kicking myself hard now) nursed it a few miles to an auto parts store and it took approx 1.6 qts to bring it up to full, drove home conservatively. Oil and filter change the next day, no visible metal in the filter or in the oil, New Mann filter and mobile 1 0w-40. I have driven about 500 miles since the oil change, I'm getting black soot on the driver side tail pipe, but no CEL, and no noticeable oil consumption (I would give anything for a normal dipstick).
Did I just make a $25K mistake in my haste? Also, would switching to a heavier weight oil make sense at this point?
Assuming I have some scoring in at least 3 cylinders, and no audible ticking. I'd like to get another 10-15k out of it before rebuilding the motor from a life/finances standpoint. Am I past that point, and a rebuild is necessary immediately, and to keep driving it will grenade the motor?
Sorry for kind of thread jacking, I'll gladly take off line.
01-20-2018, 02:38 PM
#117
Rennlist Member
More recently, we've started to correlate failing injectors due to E10 fuel and cylinder failures on those cylinders with injectors that are leaky or have poor fuel distribution. It's common enough that we came up with a injector bulletin.
01-21-2018, 06:01 PM
#118
Has nothing to do with mileage. I can make generalizations that cars from colder climates have more issues with cylinder scoring historically, or those cars that are driven short distances repeatedly.
More recently, we've started to correlate failing injectors due to E10 fuel and cylinder failures on those cylinders with injectors that are leaky or have poor fuel distribution. It's common enough that we came up with a injector bulletin.
More recently, we've started to correlate failing injectors due to E10 fuel and cylinder failures on those cylinders with injectors that are leaky or have poor fuel distribution. It's common enough that we came up with a injector bulletin.
01-21-2018, 08:46 PM
#119
I'm just entering the market for my first 911, and the more I read on the 997.1 cars they look very risky. IMS, bore scoring, it just seems like alot to overcome on these poor cars. Are the 997.2 and 991's not affected by any of these major issues? If someone has the money, perhaps it's just better to bypass the 997.1's and pay extra to get into a 991? Buying a 997.1 for $40-45K and then putting another $15-20K into rebuilding the engine would make me sick.
01-22-2018, 08:39 AM
#120
I'm just entering the market for my first 911, and the more I read on the 997.1 cars they look very risky. IMS, bore scoring, it just seems like alot to overcome on these poor cars. Are the 997.2 and 991's not affected by any of these major issues? If someone has the money, perhaps it's just better to bypass the 997.1's and pay extra to get into a 991? Buying a 997.1 for $40-45K and then putting another $15-20K into rebuilding the engine would make me sick.
