77 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHScored cylinder failure for your 996, Y or N? tell us (yr, 996 Mk1 or MK2)
Reported or suspected cause
brutal cold winter we had in canada
Reported cause
No successful repair reported for this finding.
1
Identified cause
0
Suspected cause
0
Reported fixes
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that report identifying a cause
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Reported cause
Likely cause was the Brutal Cold Winter we had in Canada.
Scored cylinder failure for your 996, Y or N? tell us (yr, 996 Mk1 or MK2)
Read full discussion summary
Leading evidence: 'brutal cold winter we had in canada' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'brutal cold winter we had in canada' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Check fuel trim values (fra, rkat)' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
Only oil has been Mobil 1 0w-40 changed every 6k miles or so.
Scored cylinder failure for your 996, Y or N? tell us (yr, 996 Mk1 or MK2)
Replace oil in mine
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
Changed the oil in mine after about 5500 miles, mobile 1, old oil looked great and smelled fine, nothing much to get worked up about in the filter, didn't see anything at the bottom of the filter cover, didn't find anything when cleaning up the filter cover, car doesn't use much oil at all.
Scored cylinder failure for your 996, Y or N? tell us (yr, 996 Mk1 or MK2)
Replace oil mostly based
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Scored cylinder failure for your 996, Y or N? tell us (yr, 996 Mk1 or MK2)
Replace pistons &a rings , resurfaced all cylinders, new gaskets
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
Replaced all pistons &a rings , resurfaced all cylinders, new gaskets, replaced IMS, new belts, new chain guides, new lifters, all lubricants.
Scored cylinder failure for your 996, Y or N? tell us (yr, 996 Mk1 or MK2)
Clean car off
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
I 'd clean the car off after work and while everyone else did the same with their cars idling they'd often ask why I didn't let it warm up while cleaning it off.
Scored cylinder failure for your 996, Y or N? tell us (yr, 996 Mk1 or MK2)
Replace oil in mine
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
Changed the oil in mine after about 5500 miles, mobile 1, old oil looked great and smelled fine, nothing much to get worked up about in the filter, didn't see anything at the bottom of the filter cover, didn't find anything when cleaning up the filter cover, car doesn't use much oil at all.
Scored cylinder failure for your 996, Y or N? tell us (yr, 996 Mk1 or MK2)
Coverage and how to read this overview
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
77 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
1 acknowledgements have no verified action link; they do not establish a repair result.
I'm curious. Since owning my porsche, I've read and seen a lot more cylinder scoring issues than IMS.
I would like this thread to document the known scored cylinder failures on rennlist. there's tons and tons of theories out there on the cause, but this isn't why I created it, I'm genuinely interested in the numbers of failure, & where the vehicle spent it's time.
me...
2002 3.6, C4S.
discovered scored cylinders at the 106 000km mark (~65k miles)
Canadian Vehicle
Anti case of what you are looking for as there is no sign or symptom of scoring, but still may be of some value.
Just had the top of the cylinders scoped and they came back clean. Without other signs of concern I don't know when we'll drop the pan and look at the bottom of the cylinders.
One owner 2001 C4 6mt with 70k.
Mobile1 for all but the last 2 oil changes (Motul is what the new Indy likes, but I think I'll go back to M1).
Changed the oil mostly based on miles (5-7k). Some had over a year time interval.
Never changed oil weights based on the season.
Never have needed to add oil between changes and the level has never dropped significantly.
Car has always been 100% street parked.
Car has been started and driven in single digit and low triple digit temps.
We have been much better about warming it up in the last few years than for most of it's life.
Saw almost daily usage for it's first 10 years with a good mix of distances and driving conditions.
Last 5 has seen much less usage and what there is typically is barely long enough to warm it up.
She'll get on it from time to time, but she can pull 20+ MPG out of it.
I drive it like we stole it and tend to run it down to a 14MPG average
Much of that may be viewed as apocryphal by some and will give at least one an aneurysm, but it is what it is and it hasn't let us down or given us any significant problems.
The problem is that this somewhat isn't dependent on how old the car is, but if the right person creates the right set of conditions. IMO
Changed the oil in mine after about 5500 miles, mobile 1, old oil looked great and smelled fine, nothing much to get worked up about in the filter, didn't see anything at the bottom of the filter cover, didn't find anything when cleaning up the filter cover, car doesn't use much oil at all.
Just guessing that my cylinders are fine, and even if they weren't I'm not in a $$ position to do anything about it anyway.
AWD, just by reading the research it seems that most engines have these things in common;
Use in colder climates.
Extended oil change service schedule.
Wrong type of oil or wrong oil for their climate.
To protect against bore scoring, you can use an oil more suited for the M96, limit cold weather operation and cold starts w/o a block heater, etc., and do not leave vehicle parked outside exposed to weather, especially cold.
2004 996 C2 Borescoped at 87k miles and no detectable scoring.
Cold climate car. I purchased as CPO in 2007 with 23k miles.
Car originated in Alaska and it has been driven year round during my 8 years of ownership in NE PA.
Oil changes at 5,000 miles using Mobil 1.
Never idled to warm her up. I 'd clean the car off after work and while everyone else did the same with their cars idling they'd often ask why I didn't let it warm up while cleaning it off. Never felt like getting into the explanation of Porsche's recommendation so I'd just say idling cars get 0 MPG.
Having heated seats does help take the chill off though.
I had a Scored Cylinder at 195km in Feb 2014. Had the Motor Rebuilt put about 30km on it already. Likely cause was the Brutal Cold Winter we had in Canada. IMS was like Brand New
I have a MK2 4S. Scored cylinders 4-6, I found out at about 104k KM. It was a DD in Alberta and it was discovered after a borescope was done when a knocking sound appeared in the spring.
It had 5000km oil changes and was stored in a non heated garage. In my circumstance I think the cold was a contributing factor.
There was a shop owner on Pelican a month or so ago and has reported several cars with scored cylinders from California.
http://forums.pelicanparts.com/off-t...cylinders.html
Yes 2002 C4S, driven daily up until 2012, winter driven and left outside in freezing every work day in winter.
2008 76k km started a rhythmic ticking and noticed it burning more oil then normal
2010 106k km the tick was louder and burning more oil, used to go through at least 1 liter a track weekend, started blue smoke under cold startup but fine after it's warmed up.
2012 120k km I had it scoped, #4 scored
2016 Now at 136k km ticks loud when cold until warmed up and driven hard, then the tick gets quieter, blue smoke at cold start for about 20 seconds
2018 Now at 137k km. Engine apart #4 #5 #6 scored bad at the top. 1-3 are good.
Mine is a '99 C4 that had a Porsche replacement engine put in. The replacement engine scored the #6 cylinder at about 65k miles. Used year round in upstate NY. Only oil has been Mobil 1 0w-40 changed every 6k miles or so.
I've always done oil analysis reports. After last winter the oil analysis came back with high aluminum and silicon (cylinder walls) and the car developed a ticking noise.
P.S. I thought you guys would like seeing my last 3 oil analysis reports - aluminum and silicon have been increasing from the first sample I took 2 years ago.
Does anyone know what the piston skirt coating is made of? Note how copper went down - if that's part of the skirt coating, perhaps there wasn't any more to wear off!
None on my Canadian 2004 c2. I change the oil every 6 months (3000 km or less) ow40 winter 5w40 warmer months. I don't have a cold thermostat but I am running Evans waterless coolant to eliminate localized boiling and hot spots.
and another, hasn't been confirmed, but I'm pretty confident listening to that motor....
https://rennlist.com/forums/996-forum/929414-help-engine-knocking-noise-w-video-and-audio.html#post13204050
2011: 106,000 km, scored #6. Oil usage had been creeping up over 2-3 years to the point where it was going through 1L per 1000kms. Oil and filter changes every 5K with Mobil 1 at the dealer.
Car was winter driven then, but garaged every night. Up the back straight at Mosport, blinking CEL came on and the car started running rough (yeah it was running on 5 cylinders!).
I elected to sell the engine as is to a tech at the dealer and buy a factory fresh X51 engine. I got a smoking deal and a 2 year Porsche warranty for a little less than what I was being quoted to rebuild the engine.
The new X51 hasn't consumed a drop of oil between changes but the car never sees extreme cold winter duty anymore. Very happy outcome.
Also look at the Hartech theory. They believe that in the later 996 997 motors thr favtory used a head gasket that would fit either bank (to save money of course) but to do so the gasket had to have all the coolant cut outs the same size. Previous gasket had cut outs that had much bigger openings for 6 and 5 cylinders since they Were the furthest from wster pump and would overheat.
So the new gasket caused 6 to overheat and score.
I do not concur with that theory at all. The change that was made was not significant enough to cause this issue. If anything were to occur from this head gasket change, it would be a cracked cylinder head.
say someone was going to write to Porsche about their 1st Porsche owning experience and their disappointment with the frequency of scored cylinders, where would once send such a letter?
lol, you never know.
I wrote to canon once for an issue I felt was a quality control thing.
They must of thought the same as they sent the newest camera and a carrying bag as replacement.
All I buy now is Canon products when it comes to my camera needs.
True. My dad has a similar story about Bose speakers that were older than I am now that got trashed in their last move. They couldn't/wouldn't fix them and instead gave him couple of sets of their satellite system which actually worked out better for the new house.
I would suggest not expecting a 991 to show up in your driveway though
"Arguing with a German about technical things is equal to banging you're head on a Titanium I beam..
__________________
Jake Raby"
Oh to be a fly on the wall when such conversations occur :-). I hope he doesn't mention Winston Churchill to said I beam!
I haven't had my bores scoped but here is my story.
Bought car in April 2016 with 47k miles
Immediately noticed sooty driver side tailpipe.
Car used about 1 qt of oil per 1500-2000 miles depending on how hard I drive and how near the top of the dip stick I fill it. I noticed that if I just add oil to keep the level above the low mark, I seem to use less oil.
In 11 months I have put 20k miles on the car and am at 67k now.
I garage the car in CT.
I drive it almost everyday 60 miles round trip to work. Mostly highway.
I use Motul 8100 X-cess 5W40 for last three oil changes.
In last two months I am starting to notice a slight ticking noise. It comes and goes and can never be heard once the car is above idle. I don't really get any blue smoke or white smoke. Maybe a tiny bit every once in a while.
Side note, I replaced spark plugs and didn't torque them enough. Since then I have tightened them with a 3/8 drive torque wrench. They actually loosened up a good amount from my hand tight estimation of proper torque. I have not verified driver side plug torque but there is a small chance some of my noise is from loose plugs. Wishful thinking.
Here are my recent oil analysis.
Just curious, did you take your oil sample the same way for these three reports? Once I did something dumb and took a sample by pulling the oil filter canister. Trying to go cheap and not change the oil. The report I got back was pretty high on aluminum.
Van, You asked about the original piston skirt coating. IIRC it was iron. But the application process was deemed environmentally undesirable ,so you can't get the same coating now. There are several after market options. I used Line 2 Line Coatings on my rebuild. They were great to work with.Time will tell if their coatings are equally good !
https://www.line2linecoatings.com/
But ignore my comments until Jake replies !
Yep..Scored cylinders with 79,000 miles. Started with small white smoke on start up then the classic ticking sound. Took to dealer and another independent shop and both used scope and determined scored cylinders in 4 & 6. Rebuilt entire engine and after 13,500.00 she's back on the road.
Replaced all pistons &a rings , resurfaced all cylinders, new gaskets, replaced IMS, new belts, new chain guides, new lifters, all lubricants.
Thoughts
I'm looking to purchase a 2002 996 tt with approx 53k miles on it. Car has been in New Jersey for two years and I live in Louisiana. I'm worried about cylinder scoring being an issue, will a PPI catch onto it, even if the problem is early on (just started).
I've also been looking for a company to provide an extended warranty for this car but have had no luck. Any recommendations? I would feel a lot better with an extended warranty. Thanks.
-Ben
I second AWDGuy.
The TT/GT engines is supposed to have Nikasil liners, which is the fix for the regular 996/997 cars.
Regular PPI won't typically catch this, it didn't for me. But apparently to the trained ear you can hear the tapping/ticking noise that is synonymous with a scored cylinder.
But you can always pay more to have the bores scoped if you are really worried about it.
Thank you both for the prompt replies. I'll probably pay to have it bore scoped for piece of mind. Bore scoping is not an engine out procedure, correct? And will the dealer do that or would I have to go to an Indy shop?
Sorry if these are newbie questions. I plan to DIY most everything, but a ruined engine will be a tough pill to swallow.
Thanks again
2002 C4S, purchased 4/2016 with 47k miles. Motor running well with no noises. Burning about a QT per 1500 miles and rear left exhaust sooty since purchased.
Driven daily even into winter. Around 64k miles in 1/2017, developed a tick. Oil consumption not really changing, no blue smoke at startup.
Jan 2018, 78k miles. Tick slowly developed to a knock over last year. Oil consumption still is not much worse. Car runs very well and has nice power. Starting to use Redline 5W50 now.
Over the last year I have used Ceratec as I know the end of the engine may be soon anyway. However, I am still getting good UOAs. I also have very little metallic paste on magnetic drain plug. Oil filter is always clear. I suspect the cylinder clearances are just getting to loose.
My guess is that I have another 10-15k miles before the knocking becomes to embarrassing to keep driving. To maximize the time left before the rebuild, I am driving somewhat conservatively when it comes to over 5k revs.
At least it will be fun weighing out all the rebuild options. Hopefully that will be a 2019 activity.
If you have access to a Durametric or PIWIS, check your fuel trim values (FRA, RKAT). We've seen a direct correlation to bad (dirty/leaky) injectors wiping cylinders out.
Even on engines that don't have scoring, we have seen ovality and taper issues lead to noisy cylinders. The best thing you can do there is make sure you use a good quality oil and make sure you keep the engine cool. Add a low temp thermostat and pull your bumper cover and make sure your radiator isn't blocked with road debris, which impedes airflow and reduces cooling system efficiency.
They should be approximately 1.0. Anything above 1 and the car is adding fuel, below, it's pulling fuel.
Another good test for health of the engine is to pull a manometer reading from the oil fill cap. Tony Callas at Callas Rennsport offers a kit along with instructions and values for most modern Porsche models.
2002 996: had the IMS done, engine failed at 75K believe it was a cylinder, no compression anywhere, ended up getting a mustang GT (this lasted 6 months) now back in a 997.2 :-)
rkat is idle trims, measured in %; out of spec is anything outside of +/- 4%.
fra is low load trims, measured as a numberic deviation around 1; out of spec is anything outside of 0.7 to 1.32.
as stated + % or over 1 is adding fuel, otherwise taking fuel away. trims are a result of dme determining how combustion is going via the o2 sensors - intent of trims is to address failing/aging components (air leak after maf sensor, injectors going out of spec, etc.). so if injectors are clogged computer will try to add more fuel to compensate and this will show up in the trims. note o2 sensors only work in a low load situation; in a high load situation computer adds addnl fuel to cool engine howver results go unmeasured as o2 sensors dont work for this richer air/fuel ratio. bad injectors can result in engine running hot, which causes detonation, damage, etc.
This is a source reference. Confirm exact model applicability in the original material.
