EPC light
10-25-2010, 05:46 PM
#31
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Gasoline is a hydrocarbon compound. It has carbon in it.
"Gasoline is a complex mixture of over 500 hydrocarbons that may have between 5 to 12 carbons."
http://www.elmhurst.edu/~chm/vchembook/515gasolinefs.html
See those graphical representations, the "C" is carbon.
"Gasoline is a complex mixture of over 500 hydrocarbons that may have between 5 to 12 carbons."
http://www.elmhurst.edu/~chm/vchembook/515gasolinefs.html
See those graphical representations, the "C" is carbon.
10-25-2010, 07:13 PM
#32
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Rhytid, OK, so it should be obvious how the injectors can get coated with carbon, even if the oil remnants did not reach the injector.
Have you notice that an engine running rich produces carbon black smoke? Burning oil tends to be blue.
If the injectors are running very low duty cycle, a lot (very low flow) and never get full flow for extended periods, I could see where it might get clogged by the fuel. If someone idles the engine a lot, without really driving it very hard, there may be a higher tendency for the injector to get clogged worse. Normal injectors get clogged, but they run at much lower pressures, than the FSI.
As for carbon buildup, there are two separate issues, one is the injector , the other is the intake valve, due to different causes.
Have you notice that an engine running rich produces carbon black smoke? Burning oil tends to be blue.
If the injectors are running very low duty cycle, a lot (very low flow) and never get full flow for extended periods, I could see where it might get clogged by the fuel. If someone idles the engine a lot, without really driving it very hard, there may be a higher tendency for the injector to get clogged worse. Normal injectors get clogged, but they run at much lower pressures, than the FSI.
As for carbon buildup, there are two separate issues, one is the injector , the other is the intake valve, due to different causes.
10-26-2010, 06:46 PM
#33
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Yes I do mainly city driving and a lot of low RPM crawling. But 600k worth and another episode?! I am not sure what's up. And it seems neither do they.(Audi - my dealership, national service dept, or Audi AG Germany.
In terms of Rhytid's thoughts - they too were questioning this possibility. They pressure tested the engine and it holds well with no suggestion of ring/cap that has malfunctioned.
Anyone else with any other thoughts? I'm all ears. I'm fighting hard to get them to just do a vehicle substitution. Remember I put in almost $3k of film and full ceramic tints so this is not an easy thing for me to request. But these issues began at 1100k so I have completely lost confidence.
I have seriously thought about not coming back to the S4 which is sad as it's the car I truly wanted and everything else out there is just 'eh'. But I need a reliable car...
In terms of Rhytid's thoughts - they too were questioning this possibility. They pressure tested the engine and it holds well with no suggestion of ring/cap that has malfunctioned.
Anyone else with any other thoughts? I'm all ears. I'm fighting hard to get them to just do a vehicle substitution. Remember I put in almost $3k of film and full ceramic tints so this is not an easy thing for me to request. But these issues began at 1100k so I have completely lost confidence.
I have seriously thought about not coming back to the S4 which is sad as it's the car I truly wanted and everything else out there is just 'eh'. But I need a reliable car...
10-29-2010, 06:52 PM
#35
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Its provincial/state jusrisdiction for lemon laws. Unfortunately mine down not have one. I also understand with this laws is that you are reimbursed the lowest black book value for the vehicle - which obviously sucks given the time and energy put into this new ownership an the fact that the car was 7 weeks old! Anyways - I am trying to work through the appropriate channels to see if the dealership can push something through-they are a premier dealership in Canada so let's see...
10-31-2010, 05:03 AM
#36
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Hi,
Yesterday driving to my folks house I had the same light come up. The engine sounded rough straight after so pulled up and turned the engine off. Left in a couple of mins then restarted and it has been ok since. Hope it doesn't reoccur.
My car has only done 2k and so far has been a joy to drive.
James
Yesterday driving to my folks house I had the same light come up. The engine sounded rough straight after so pulled up and turned the engine off. Left in a couple of mins then restarted and it has been ok since. Hope it doesn't reoccur.
My car has only done 2k and so far has been a joy to drive.
James
10-31-2010, 06:14 PM
#37
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Hey James - you can only wait and see. May I ask when you took posession - maybe it's a common time in production given we have similar mileage on the vehicle. If you take your car in - do report your codes please.
10-31-2010, 10:57 PM
#38
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I picked up my car on September 1st (2011 model year)
Was planning on seeing if it does it again before calling the dealer.
James
11-02-2010, 12:28 AM
#40
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James