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I miss the point. The guy points out that the DFI motor will have problems because his 2008 motor had problems. Does that mean a peach will be crunchy because an apple is crunchy?
His 2008 engine is a DFI MY09, mind you. Again, he is not alone:
Turned out not to be bore scoring. It was a misaligned piston ring allowing too much oil in to the cylinder, hence the smoke and huge oil consumption.
All new modified piston heads and cylinder linings rebuilt under warranty and all is well.
Wouldn't worry about bore scoring in a gen2.
Originally Posted by Wayne Smith
Yeah, we will all be hunted. Maybe it is time to change the forest we are being hunted in.
You didn't get it! I'm in the market for a 997.2 after thoroughly considered other options.
Therefore, the last thing I need is misleading information to say the least.
You didn't get it! I'm in the market for a 997.2 after thoroughly considered other options.
Therefore, the last thing I need is misleading information to say the least.
Im done after this post (it's been fun!) but your second link actually underscores no bore scoring (I didnt read first link), if you read the link yourself? The conclusion in that thread was that the DFI motor suffers no major reliability issues... are you googling "bore scoring" and hoping to trick people? You are digging your own hole on here...
There is clearly no major issue with the DFI engine or it would have come out on the forums by now. There will be failures, but not out of what is ordinary across any OEM/brands: Toyota, Honda, everyone experiences low rate failures and then that gets split between user abuse and actual defect. IMS was a specific, higher event issue. Frankly, unacceptably high. The problem there was in the design and implementation. It wasn't merely caused by a faulty component/mfg defect.
You realize your posts wont have any impact, at all, on 997.2 prices, the view on the brand, etc. Not sure how you are diligencing your own purchase by narrowly focusing on a non-issue and not exploring anything else on these forums... strikes as very, very odd.
Im done after this post (it's been fun!) but your second link actually underscores no bore scoring (I didnt read first link), if you read the link yourself? The conclusion in that thread was that the DFI motor suffers no major reliability issues... are you googling "bore scoring" and hoping to trick people? You are digging your own hole on here...
There is clearly no major issue with the DFI engine or it would have come out on the forums by now. There will be failures, but not out of what is ordinary across any OEM/brands: Toyota, Honda, everyone experiences low rate failures and then that gets split between user abuse and actual defect. IMS was a specific, higher event issue. Frankly, unacceptably high. The problem there was in the design and implementation. It wasn't merely caused by a faulty component/mfg defect.
You realize your posts wont have any impact, at all, on 997.2 prices, the view on the brand, etc. Not sure how you are diligencing your own purchase by narrowly focusing on a non-issue and not exploring anything else on these forums... strikes as very, very odd.
+1
Peace
Bruce in Philly (typically paranoid but not with DFI engines)
As a developer who shared what he learned, in a forward and direct manner with the M96/ M97 engines, I caught a lot of flack. Terms like "fear monger" didn't sit well with me.
My last 5 years have been spent researching and developing the 9a1 engines, both DI and port injected. With these I am not making the same mistakes that I made with the M96/97 engines, and sharing what I've learned online. People don't want to hear the truth, they just want to believe that its all Unicorns and rainbows in the mechanical workings within their engines. Most of them don't even believe problems can occur when their own engine snaps a timing chain and blows it through the cam cover; they certainly won't believe anything thats written.
There's a reason why we bought a new car in early 2010 and took the engine apart straight away. My record is pulling a 9a1 apart with 11 miles on the odometer.
+1
Jake, I have to agree with you. Unfortunately, people don't care about the truth.
Please, tell me if you experience with the 9A1 engine can confirm that cylinder bank #1 is the most affected and then I will be out of here.
Oh, and another thing that may help you in your diagnosis, if you have paid attention to the last two links above you can read the following in one of them:
After much debate with Porsche GmBH, pictures, measurements they're replacing the pistons (apparently 991), crank casings and rebuilding the thing.
It seems that the 9A1 engine pistons got an uprated version transitioning from the 997.2 to the 991 model. Who would thought about that?!
Jake, you also need to buy a new 991 to pull out the engine straight away and take full awareness of the "little differences" inside!
We've already got a line on the newest engine. I have had several 2014s apart already.
the new GT3 RS 4.0 will be here after the new owner drives it in stock form for 4-6 weeks, thenm its time to make it 4.2 or larger and get way ahead of the rest, again.
As for wear, my biggest issues are on bank 2, its where I see broken rings and worn cylinders the worst. There's a reason for that, and it follws the M96/97 as well as the Cayenne V8.
Again, thats all I have to say on the topic of 9a1 failures. You guys will hear enough in the future without my input. Now that my M96 book is done, ai Have already started on the 9a1 assembly manual and "definitive guide".
The 997.2 I'm interested in and went to see the other day exhibited a small puff upon cold startup from rear left tail pipes whilst none on the other side, that's the reason why I'm suspicious of cylinder bank #1 with the DFI engine. Also, the following picture of the 997.2's 9A1 engine shows cylinder #3, which also means cylinder bank 1. Moreover, in the cylinders from bank 1 the fuel injectors point directly downwards to the lower wall side of the horizontally disposed cylinder, which in the bank 1 corresponds precisely to the piston thrust side where the piston force is higher (it's the opposite with cyl. bank 2). Since, the coolest coolant enters bank 1 from the bottom first, it means that the thrust side will tend to run cooler and so fuel intrusion (there's less evaporation) is favoured even further on that side's wall. The necessary oil film between piston and bore can therefore be 'washed' away from the cylinder walls past the rings and promote the inevitable bore scoring. Lower outside temps only favour the phenomenon even further with the consequent fuel dilution from richer fuel/air mixture and water that is not evaporated from the oil due to a cooler running engine leading to poor oil characteristics, which adds to the problem. It's a snow ball, literally.
Last edited by CaymanPower; 02-25-2015 at 04:45 PM.
The 997.2 I'm interested in and went to see the other day exhibited a small puff upon cold startup from rear left tail pipes whilst none on the other side, that's the reason why I'm suspicious of cylinder bank #1 with the DFI engine. Also, the following picture of the 997.2's 9A1 engine shows cylinder #3, which also means cylinder bank 1. Moreover, in the cylinders from bank 1 the fuel injectors point directly downwards to the lower wall side of the horizontally disposed cylinder, which in the bank 1 corresponds precisely to the piston thrust side where the piston force is higher (it's the opposite with cyl. bank 2). Since, the coolest coolant enters bank 1 from the bottom first, it means that the thrust side will tend to run cooler and so fuel intrusion (there's less evaporation) is favored even further on that side's wall. The necessary oil film between piston and bore can therefore be 'washed' way from the cylinder walls past the rings and promote the inevitable bore scoring. Lower outside temps only favour the phenomenon even further with the consequent fuel dilution from richer fuel/air mixture and water that is not evaporated from the oil due to a cooler running engine leading to poor oil characteristics, which adds to the problem. It's a snow ball, literally.
While fuel is a solvent and will wash the oil away, you are judging a book by it's cover.
A disassembled engine, and a micrometer tell the story. After you see a few dozen the story starts to tell it's self.
It isn't the smoke at start up, it's the color of the tail pipes at shut down. In this case start up smoke has to do with cylinders stopped on their sides (horizontally) combined with gravity (for you science believers). Smoke does not necessarily mean fire.
I'm done with this post. Too much hate. Too much effort creating negative. Not enough of how I want to spend my spare time.
If anybody has anything pertinent to say, please say it on a new post.
And this is the kind of smoke I got from cyl. bank 2 and none from bank #1... but then again, despite of being the 9A1 engine it wasn't the DFI version
QUOTE=CaymanPower;9263178]
It was only until I managed to show them, by rerouting and split the exhaust tailpipes, that the engine only smoked from one engine side (bank #2) that they finally acknowledged the problem:
02-25-2015, 10:36 AM
