dfi motor carbon build up possible
03-20-2010, 09:18 AM
#16
Drive it harder. Many with 997.2 have noticed that sooty deposits at the exhaust tips turns to a light grey or almost invisible residue after track events.
I have noticed big clouds of black soot out the back of my wifes DFI Cayenne V8 when i drop the hammer on it.
I have noticed big clouds of black soot out the back of my wifes DFI Cayenne V8 when i drop the hammer on it.
03-20-2010, 02:01 PM
#17
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Since you are very familiar, is 9A1 totally different than the Cayenne DFI too?
I just came across these:
http://www.planet-9.com/cayman-boxst...-good-buy.html
http://forums.audiworld.com/showthre...t=carbon+build
I just came across these:
http://www.planet-9.com/cayman-boxst...-good-buy.html
http://forums.audiworld.com/showthre...t=carbon+build
03-20-2010, 02:10 PM
#18
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This has been debated to death. BMW and Audi DFI engines are radically different. The 9A1 DFI has a new head design and chances are intake gunk may not be an issue. None has been reported in 9A1 engines w/ 50k+ miles so far.
BTW... the issue is not carbon buildup. The potential gunk accumulation behind intake valves is not hard carbon deposits. If it will occur... it is soft oily gunk that can be cleaned with a Top Engine cleaner.
The funny thing is that the posters with a sky-is-falling concern seem to be 997.1 owners. I wonder why?
BTW... the issue is not carbon buildup. The potential gunk accumulation behind intake valves is not hard carbon deposits. If it will occur... it is soft oily gunk that can be cleaned with a Top Engine cleaner.
The funny thing is that the posters with a sky-is-falling concern seem to be 997.1 owners. I wonder why?
03-20-2010, 03:12 PM
#19
Nordschleife Master
whats new about them..dfi is a problem not the head designs..unless porsche somehow posistiond the injecters in a diff location there will be gunk on the intake side of the valve no matter what heads they use..because the injecter is in the piston track and not been sprayed in the intake like port injection..
And no... no need to pull heads to clean intake tract. A simple Top Engine treatment will do.
03-20-2010, 06:15 PM
#20
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It looks like you begin to see the light. Weissach is not stupid. It probably designed those Audi engines and learned from them. The geometry of the injector and intake valve on the 9A1 is quite telling.
And no... no need to pull heads to clean intake tract. A simple Top Engine treatment will do.
And no... no need to pull heads to clean intake tract. A simple Top Engine treatment will do.
03-20-2010, 07:24 PM
#21
Nordschleife Master
It's injected through a vacuum hose. Please note that I am not recommending this treatment as I know no 9A1 engine with such problem. The treatment is easy and it's available should it be necessary. I find it funny that this issue is only raised by non 997.2 (9A1 engine) owners. I know no one owning the new DFI 911s reporting any issues. None.
03-20-2010, 09:13 PM
#22
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It's injected through a vacuum hose. Please note that I am not recommending this treatment as I know no 9A1 engine with such problem. The treatment is easy and it's available should it be necessary. I find it funny that this issue is only raised by non 997.2 (9A1 engine) owners. I know no one owning the new DFI 911s reporting any issues. None.
03-20-2010, 09:33 PM
#23
Nordschleife Master
Please post examples of specific 997.2 DFI cars w/ 'serious carbon issues'.
03-20-2010, 09:52 PM
#24
Burning Brakes
How can anyone post any carbon issue when most owners do not drive enough miles/year?
May have to wait 5 years to determine if its a problem or not.....after P warranty expires.
abe
May have to wait 5 years to determine if its a problem or not.....after P warranty expires.
abe
03-20-2010, 10:10 PM
#25
Nordschleife Master
Abe: I agree with you but there are already several high mileage 997.2 I know of with no issues. This seems to me to be a ghost chase which seems to be a common sport.
There are known DFI issues wit BMW and Audi but the 9A1 engines are different and their heads have a different design. It is one thing to identify a real problem and debate it, it is another thing to speculate about a ghost.
There are known DFI issues wit BMW and Audi but the 9A1 engines are different and their heads have a different design. It is one thing to identify a real problem and debate it, it is another thing to speculate about a ghost.
03-20-2010, 10:47 PM
#26
You seem to be intent on creating a problem where none exists (on Porsche's). And I am perplexed on why you would want to do that? I call bull**** on your claim: "and they have serious carbon issues". That is a bald faced lie.
I am pulling the Troll Alert alarm...
03-20-2010, 11:44 PM
#28
Still plays with cars.
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I a curious too. My 997.2 has been perfect although I have only 12,000 miles and one year on it. Other than an oil change and winter wheel/tire swap, no visits to the dealer for any reason. Oops no, I forgot., the Porsche logo fell off my key. Excess carbon perhaps?
03-21-2010, 12:14 AM
#29
I had nasty sludge on the tops of my intake valves from using crappy gasoline. I'll be using Chevron with Techron from here forward.
Oh wait, mine's a non-DFI V8... never mind.
Oh wait, mine's a non-DFI V8... never mind.
Last edited by JohnnyBahamas; 05-22-2013 at 12:36 PM.
03-21-2010, 12:44 AM
#30
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Abe: I agree with you but there are already several high mileage 997.2 I know of with no issues. This seems to me to be a ghost chase which seems to be a common sport.
There are known DFI issues wit BMW and Audi but the 9A1 engines are different and their heads have a different design. It is one thing to identify a real problem and debate it, it is another thing to speculate about a ghost.
There are known DFI issues wit BMW and Audi but the 9A1 engines are different and their heads have a different design. It is one thing to identify a real problem and debate it, it is another thing to speculate about a ghost.
However, I agree with you that this is a non-issue for 997.2 right now, either due to the fact there's not enough cars with high milage, or, becuase of the new head design.