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Lol I realize that any engine can go any time etc etc etc.
I'm just wondering if a potential crankshaft "issue not problem" could reasonably be credited with an elevated risk.
IMO if a well taken care of engine (proper warm up, cool down, oil changes and scheduled maintenance) should last an absolute minimum of 150k miles. I'd expect that from any modern manufacturer or brand period, and if not then something's severely wrong. 200-300k are reasonable for a quality well engineered engine IMO.
Yes the bell can toll (really?) for any engine ever made in history. But that's meaningless mechanical sophistry to say that.
If this "issue" is crankshaft related, can it reasonably effect engine longevity in general?
StudG,
I agree with you and I hear you.
As shi**y as it sounds I was told it's still within "acceptable" specs. Go figure. Kinda like a general in battle telling his officers the losses will be X. "We can live with that."
Porsche sold 10,442 911's in the United States alone last year. That's a lot of motors (engines) lol.
It's a small enough difference that it won't shake your crankcase apart. It's only around that rpm. Unfortunately, it just so happens to occur down in the most used rpm area of the powerband. The vibration gives the sensation of a power loss when the engine and trans are under load. That's why making adjustments to the "tune" won't help.
I'm sure if someone just couldn't take it anymore and pushed the issue with a dealer over and over they could probably get out of their car. Look at what Murray had to go through to get his problems resolved. To be honest, if I had been him I would have probably given up and that's what Porsche obviously wanted him to do. He didn't and good for him. He did have a witness though. That little dog riding shotgun sure looked cute when the car stalled going over that speedbump, looked over at the camera and gave the WTF look?
Lol I realize that any engine can go any time etc etc etc.
I'm just wondering if a potential crankshaft "issue not problem" could reasonably be credited with an elevated risk.
IMO if a well taken care of engine (proper warm up, cool down, oil changes and scheduled maintenance) should last an absolute minimum of 150k miles. I'd expect that from any modern manufacturer or brand period, and if not then something's severely wrong. 200-300k are reasonable for a quality well engineered engine IMO.
Yes the bell can toll (really?) for any engine ever made in history. But that's meaningless mechanical sophistry to say that.
If this "issue" is crankshaft related, can it reasonably effect engine longevity in general?
Theoretically, of course it will. This is one of the reasons for balancing, that balanced parts result in lower stress and wear factors, especially on moving parts like the crank, main and rod bearings, but also of course on the crank case, transmission, motor mounts and frame. In practice however there are so many other wear factors that balancing hardly even matters- at least not as long as its in some "normal" range. Beyond "normal" to me means something everyone would notice, not what someone has been driving every day and you have to tell them to stop and rev the engine very slowly and pay attention.
I find it extremely unlikely, verging on impossible, that Porsche has knowingly released the 991 with an engine so freakishly out of balance that it interferes with drivability or poses a threat to longevity, and yet at the same time nobody in three years has complained about their engine being out of balance! In fact this is the first time, the one and only time, in all that time, that I even recall anyone bringing up the subject. Anyone? Anyone? Beuller?
That makes sense, and I want you to be right as well. I'm actually budgeting for an engine rebuild (factory or aftermarket) when the time comes, as I keep cars a long time, really like this one, and don't mind "paying to play". At least as long as it's reasonable in concept and I'm paying for quality.
150-200k on an engine as good as this and I'll happily pay for a rebuild (but not a rejected core!) Especially for an issue they knew about since almost the beginning that they later try to essentially double charge us for.
Hopefully the issue is just a hard to notice minor annoyance that doesn't significantly effect longevity. I can live with that, as we all know they're not stop selling the line and crate motoring 100,000 of these things under any circumstance and I wouldn't expect it. I would expect a reasonable amount of good will like a nominal discount off a rebuild with guaranteed core credit or something. We'll see when the time comes. By then there'll hopefully be a well established aftermarket rebuilt market anyway, though is like to keep things factory if possible.
The only hesitation I have with my 2014 991 is whether to drive it in the rain or not. Mostly not. No issues so far. Hope it stays that way. Hopefully, those of you who are will get it resolved soon.
Has anyone used a bluetooth OBD2 reader and recorded with the Torque app to capture the engine data during the "stumble"?
I was wondering this too... Someone who understands a little about engine data & the Torque app could come up with the appropriate data layout for the Torque app to display/capture the relevant info in a video overlay such as shown here (skip to 4mins in)
Then share that layout with others here, and with multiple people gathering the same data points, and sharing that info, perhaps solid correlations can be found among the 991's that have the issue and the ones that don't.
Ie, if you can see & hear a dashcam video that is experiencing the stumble, and see engine/performance data overlaid as it's happening, it might help pinpoint the cause.
wow, pdk have been around since 2009 i believe, and from what I have gather, this same problem have been discuss and still the subject is back again.
Please let me add my little exp with dct, I own a 2009 GTR for 5yrs, finally trade in for the 50th 991, manual of course. One of the main problem with the GTR is city driving, light load slight pause in 1st to 2nd, characteristic in dct transmission when the computer is slow to shift, then you manually shift yourself but the pause still there in stop and go traffic ( light load)
Nissan suggest clutch relearn every 12k mile or every 1yr. I notice after 2 yrs of driving it without relearn, it keep getting worse and worse.
Last year, went to my Porsche dealer, wanted to get a GT3, but news came of it only avail in pdk mess up that plan. Then next best thing, 50th edition in 7sp Manual, bad news is my dealer only have a 50th with PDK coming in, and my SA keep convincing me its better than anything in the market or MT in the world, so he made me test drive brand stinking new 2014 4s with PDK. I was hoping he is right, but after a brief driving, I notice there is a slight pause just like the GTR, just a tiny little. I tried more stop and go test light load, and results the same. Under hard throttle you won't feel it, just like the GTR.
So to make it short, I afraid the PDK have similar symptoms as the GTR. Thats just how they are, I don't know if Porsche have that clutch relearn thingy that Nissan have, or any PDK software update. I been busy driving the 7sp MT, and the only problem I come across is that PDCC. No pausing between 800-900 rpm or 2500. I don't know if all this mumbling helps, sorry that you guys still having this issue.
09-30-2014, 02:13 AM
