View Poll Results: Poll: Have you had bore scoring on your 997.1 or 997.2 engine?
Yes, 997.1 (05-08 MY)
143
14.44%
Yes, 997.2 (09-12 MY)
18
1.82%
No, 997.1 (05-08 MY)
526
53.13%
No, 997.2 (09-12 MY)
303
30.61%
Voters: 990. 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)
#151
5th Gear
Join Date: Oct 2013
Location: Southern California
Posts: 5
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No symptoms of bore score
Purchased 2005 C2S with 18k miles in 2013 with PPI. Currently 39k miles, 28k replaced stock IMS with EPS IMS (old IMS perfect), clutch and RMS (clutch barely worn), water pump replaced at 28k miles but old one looks like new, low temp thermostat at 32k miles, religious oil changes with Motul 5W-40 and switched to DT40. Warm climate (California) but always warmed prior to giving it the beans. Added LN spin on oil filter at 32k miles to avoid oil bypass in stock filter. Love the car but scoring is always in the back of my mind. No soot/ticking. Fingers crossed.
#152
Racer
Purchased 2005 C2S with 18k miles in 2013 with PPI. Currently 39k miles, 28k replaced stock IMS with EPS IMS (old IMS perfect), clutch and RMS (clutch barely worn), water pump replaced at 28k miles but old one looks like new, low temp thermostat at 32k miles, religious oil changes with Motul 5W-40 and switched to DT40. Warm climate (California) but always warmed prior to giving it the beans. Added LN spin on oil filter at 32k miles to avoid oil bypass in stock filter. Love the car but scoring is always in the back of my mind. No soot/ticking. Fingers crossed.
#153
Three Wheelin'
Jeffblak: No. LN did the cylinder replacement and machining as well as the new parts and IMSB modifications. Local indy is putting it all back together handicapped by a real customer-nuisance factor of my presence and considerable forbearance. I've learned a lot about causes and effects, way more than I've seen published to date.
I forgot another advantage of the rebuild: (f) replacing other parts with noticeable wear (e.g., chain adjusters/guides).
I forgot another advantage of the rebuild: (f) replacing other parts with noticeable wear (e.g., chain adjusters/guides).
Interested to hear a) costs and b) your post mortem on the cause/effect and c) how your chain guides looked at 47k miles. I know this was an issue on the 996 but understand they improved the design on the 997.
#154
Racer
Well . . . you know how it is when you are selecting alternatives and options "since we have the engine apart." Cylinder 6 was badly scored, none of the others were beyond a little wear on the piston skirts. It was a clear case of a scored cylinder, plus I know roughly when it started because I was logging oil consumption. It happened on my watch, but I had been doing everything right (easy driving under 4,000 RPM until oil reached 200F, oil changes every 4,000 to 5,000 miles, etc.). I did drive in some very cold weather for WA State (i.e., in the teens), but gee whiz! Original IMS and RMS were in great shape, but I opted for the IMS Solution so I don't have to think about it again. Chain guides were definitely worn, but not worn out. Replaced guides and tensioner (LN billet tensioner). Replaced AOS, clutch, ignition cable, water pump, and a myriad of other things "just because we are in there." Basic cost was about $18.5K, but the extras drove it up to a little over $22K. The hardest part was driving the company van for four months while simultaneously going through withdrawal. However, the extra time allowed me to save up for the final bill. Now that I am driving my 997 again, I don't really notice too much more power, but I can really feel some extra, lower RPM torque. My wife also says it is louder. No measureable oil consumption (!), but my gas mileage is down a little, possibly driven by a more erratic break-in driving style. I want to actually measure everything on a dyno for a BEFORE/AFTER comparison when I get a few thousand miles on it. From my perspective, the bore score deniers/trolls are whistling past the graveyard, especially if they drive an "S."
Last edited by JustinCase; 04-29-2018 at 08:21 PM. Reason: Punctuation
#155
2007 C4S 120,000kms
Afternoon all, just got the diagnosis of bore score.
2007 C4S with 120,000kms on it. Irish car, so all elements of weather but rarely over 25 degrees C.
Over rev shows all good. I only own it since Oct of last year so I can't account for how it was used before I got it.
Symptoms were high oil usage (1.5l per 1000kms) and very sooty LHS pipes. No other signs.
Porsche dealer warranty so they're scheduling a rebuild.
2007 C4S with 120,000kms on it. Irish car, so all elements of weather but rarely over 25 degrees C.
Over rev shows all good. I only own it since Oct of last year so I can't account for how it was used before I got it.
Symptoms were high oil usage (1.5l per 1000kms) and very sooty LHS pipes. No other signs.
Porsche dealer warranty so they're scheduling a rebuild.
#158
#159
Aaaand she's back.
Six weeks, new block & pistons, new clutch, replaced alternator cable & six new plugs.
Like a new car!
Rebuild at their cost, clutch, cable & plugs at my cost.
Six weeks, new block & pistons, new clutch, replaced alternator cable & six new plugs.
Like a new car!
Rebuild at their cost, clutch, cable & plugs at my cost.
#160
Managing bore scoring...
I bought my 2006 997.1 Carrera S with the 3.8 L engine with a thousand miles on a freshly rebuilt engine from EBS because of bore-scoring according to the previous owner. While I have not poured over the invoices from EBS, I suspect the replaced parts, piston and bore liners, were OEM. Since the car is not my daily driver, I've delayed putting in time to research what EBS actually did during the rebuild. However, in my experience, whenever there is bore scoring involved with any engine, my experience tells me it's either lack of lubrication, or bore / cylinder mismatch in expansion. I've monitored the lubrication aspect of the engine, and I find it difficult to believe that in a horizontal cylinder configuration, where oil level is easily monitored on the dashboard, that the scoring is due to lack of lubrication. I am more of the belief that it is a thermal expansion issue which is why I would advocate owners of these engines warm them up very carefully before they put a substantial load on them. I find my oil temperature takes about 10 minutes to get to normal operating temperature, but at that, I still limit the load for another 5 or so minutes to ensure all the internal parts have acquired the heat necessary to get to their normal operating clearances.
#161
I bought my 2006 997.1 Carrera S with the 3.8 L engine with a thousand miles on a freshly rebuilt engine from EBS because of bore-scoring according to the previous owner. While I have not poured over the invoices from EBS, I suspect the replaced parts, piston and bore liners, were OEM. Since the car is not my daily driver, I've delayed putting in time to research what EBS actually did during the rebuild. However, in my experience, whenever there is bore scoring involved with any engine, my experience tells me it's either lack of lubrication, or bore / cylinder mismatch in expansion. I've monitored the lubrication aspect of the engine, and I find it difficult to believe that in a horizontal cylinder configuration, where oil level is easily monitored on the dashboard, that the scoring is due to lack of lubrication. I am more of the belief that it is a thermal expansion issue which is why I would advocate owners of these engines warm them up very carefully before they put a substantial load on them. I find my oil temperature takes about 10 minutes to get to normal operating temperature, but at that, I still limit the load for another 5 or so minutes to ensure all the internal parts have acquired the heat necessary to get to their normal operating clearances.
You'll find instances of both cars where people have had the issue at 20k miles and others well over 100k with not a single problem.
#162
I think letting the engine get to proper operating temp is likely a lot of it. You see wild ends of the spectrum with the E90/92 rod bearing issue and I think it's the same reason. Tons of non car guys that own them that will start the car cold and peel off as soon as they leave the neighborhood. Both are more expensive status symbol sports cars so there will be a huge population of people with them that just don't treat it like their baby.
You'll find instances of both cars where people have had the issue at 20k miles and others well over 100k with not a single problem.
You'll find instances of both cars where people have had the issue at 20k miles and others well over 100k with not a single problem.
#164
Racer
It's not clear. I purchased the car with 10,000 miles on it. Symptoms did not turn up for another 10,000 to 15,000 miles, so I believe the problem developed on my watch even though it had been at a dealer for a while and I'm pretty sure there was some hooning going on with it. Since I have had the car, I always drive it out of the enclosed garage right after starting but keep it under 4,000 rpm until it reaches 200 degrees F, and I have a long-time habit of rev-matching the shifts. While it is my DD, it rarely gets even cold enough in the Seattle area to switch out my summer tires. Winter is 25-30 degrees at night and 45 degrees in the daytime. There was one incident early on where I drove it to work when it was 19 degrees F I thought might have been the problem, except when I matched that date to my oil consumption and symptom chart, is was many, many miles and months earlier, so it's hard to believe it was the precipitating incident. I am struck by a statement Charles Navarro of LN Engineering made that *all* the 3.8s he gets in are scored, but I also know he only sees engines with problems, not engines *without* problems. Incidentally, once symptoms showed up around 25,000 miles, they progressed fairly rapidly until I had to do something by 45,000 miles. Oil consumption was dropping like a stone, and I was at 500 miles per liter when I had the engine rebuilt. I apologize for not providing a crystal clear answer. By the way, running a DME when the engine was rebuilt showed only a few overrevs in Zone 2, and only one in Zones 3,4, and 5 -- but based on the hours, that happened many, many moons ago, and before I purchased the car.
#165
Rennlist Member
Dealers are famous for starting a hipo car and revving it to show off...