Direct Injection carbon buildup
#1
Rennlist Member
Thread Starter
Direct Injection carbon buildup
My DD is a 2011 Audi S5, lovely car and sounds fabulous with its Stasis exhaust. I have it in at the dealer right now for an oil change with 21,000 kilometers on it (13k miles). I had been noticing lately that it was not starting well when the engine was hot and felt down on power. They now have the intake manifold off and are de-carbonizing the valves and intake manifold.
I found this article on the problem:
http://www.autoobserver.com/2011/06/...-adopters.html
Interesting it says that Porsche doesn't seem to be having a problem...
I found this article on the problem:
http://www.autoobserver.com/2011/06/...-adopters.html
Interesting it says that Porsche doesn't seem to be having a problem...
#2
Nordschleife Master
My DD is a 2011 Audi S5, lovely car and sounds fabulous with its Stasis exhaust. I have it in at the dealer right now for an oil change with 21,000 kilometers on it (13k miles). I had been noticing lately that it was not starting well when the engine was hot and felt down on power. They now have the intake manifold off and are de-carbonizing the valves and intake manifold.
I found this article on the problem:
http://www.autoobserver.com/2011/06/...-adopters.html
Interesting it says that Porsche doesn't seem to be having a problem...
I found this article on the problem:
http://www.autoobserver.com/2011/06/...-adopters.html
Interesting it says that Porsche doesn't seem to be having a problem...
There is an aftermarket oil catch can you can install to fix it
#3
Rennlist Member
Audi is not the only one that suffers from this.
It becomes a maintenance item. Here's how you actually fix it:
http://www.motorvac.com/index.cfm?PAGEPATH=&ID=38819
It becomes a maintenance item. Here's how you actually fix it:
http://www.motorvac.com/index.cfm?PAGEPATH=&ID=38819
#4
Rennlist Member
Thread Starter
Audi is not the only one that suffers from this.
It becomes a maintenance item. Here's how you actually fix it:
http://www.motorvac.com/index.cfm?PAGEPATH=&ID=38819
It becomes a maintenance item. Here's how you actually fix it:
http://www.motorvac.com/index.cfm?PAGEPATH=&ID=38819
#5
Rennlist Member
My DD is a 2011 Audi S5, lovely car and sounds fabulous with its Stasis exhaust. I have it in at the dealer right now for an oil change with 21,000 kilometers on it (13k miles). I had been noticing lately that it was not starting well when the engine was hot and felt down on power. They now have the intake manifold off and are de-carbonizing the valves and intake manifold.
I found this article on the problem:
http://www.autoobserver.com/2011/06/...-adopters.html
Interesting it says that Porsche doesn't seem to be having a problem...
I found this article on the problem:
http://www.autoobserver.com/2011/06/...-adopters.html
Interesting it says that Porsche doesn't seem to be having a problem...
#6
Addict
Rennlist Member
Rennlist Member
The best solution to this issue is the design in the Flat-4 motor used in the budget sports cars, Subaru BRZ, Scion FR-S, and Toyota GT86.
There they use 2 fuel injectors per cylinder. One is inside the combustion chamber (DFI) and one is farther up the intake air tract. The second one acts to wash the intake and valves (like a traditional non-DFI motor).
This allows all the benefits of both DFI (fuel economuy, high compression and specific output, HP/Liter) and non-DFI (no carbon build-up).
I wish Porsche and others would adopt this technology...
There they use 2 fuel injectors per cylinder. One is inside the combustion chamber (DFI) and one is farther up the intake air tract. The second one acts to wash the intake and valves (like a traditional non-DFI motor).
This allows all the benefits of both DFI (fuel economuy, high compression and specific output, HP/Liter) and non-DFI (no carbon build-up).
I wish Porsche and others would adopt this technology...
#7
Common problem w/ the DI Audi motors.
There was a dyno chart around where a guy lost like 35 rwhp over 20K miles due to the carbon build up in his Audi.
Other engines don't have the problem and it has to do w/ vapor routing and some other fine details.
There was a dyno chart around where a guy lost like 35 rwhp over 20K miles due to the carbon build up in his Audi.
Other engines don't have the problem and it has to do w/ vapor routing and some other fine details.
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#10
GT3 player par excellence
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that's why my RS4 dint stay long.
BMW also got this issue in addition to other stuff
BMW also got this issue in addition to other stuff
#13
Rennlist Member
I run Shell fuel and hammer the car hard after it reaches normal operating temps and haven't had another problem in two years.
My RS4 has a nice power surge at around 4500 RPM all the way till it shuts off at 8200 RPM like the 4.2 liter DFI V8 motor should.
#14
Rennlist Member
Thread Starter
Interesting solution to go to 2 injectors...
#15
Platinum Dealership
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Bought my RS4 with 23k miles, dealer took of manifold and manually cleaned valves 3k miles later under warranty due to power loss.
I run Shell fuel and hammer the car hard after it reaches normal operating temps and haven't had another problem in two years.
My RS4 has a nice power surge at around 4500 RPM all the way till it shuts off at 8200 RPM like the 4.2 liter DFI V8 motor should.
I run Shell fuel and hammer the car hard after it reaches normal operating temps and haven't had another problem in two years.
My RS4 has a nice power surge at around 4500 RPM all the way till it shuts off at 8200 RPM like the 4.2 liter DFI V8 motor should.