Keep carbon buildup out of the engine?

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2012 Audi A7 3.0T. Recently they sent out a notice about a warranty extension because of excessive carbon buildup on various parts of the engine. I'd much rather keep the carp out of it now, than pay someone $5000 to professionally decrap it later. What fuel additive could/should be used and how often?
 
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May be related to its application of direct fuel injection. The industry is always working on new fuel formulations to address this issue. Use a Name Brand fuel.
 
Originally Posted By: horse123
What fuel additive could/should be used and how often?


Good luck finding one that can be poured into the tank and help a DI engine stay carbon free if that particular engine design is prone to that problem. For the best results it would have to be fed via a vacuum line. An Inverse Oiler would probably help. Clevy and I mentioned this a few times. You might want to look into an Inverse Oiler.
 
Top Teir 91~93 octane gas, occasional Redline SI-1/Techron treatment and weekly Italian tunes for a good 20~30 miles should keep it to the minimum.
 
Originally Posted By: horse123
2012 Audi A7 3.0T. Recently they sent out a notice about a warranty extension because of excessive carbon buildup on various parts of the engine. I'd much rather keep the carp out of it now, than pay someone $5000 to professionally decrap it later. What fuel additive could/should be used and how often?


Any PEA cleaner (Techron, Gumout, Redline, Amsoil, etc.) used regularly will help keep the combustion chamber and injectors clean. That is an important step #1.

Then, keeping the RPMs up above 4500 or so for 20+min at a time will help keep the intake valves clean. This does not have to be done at high speeds, regular highway speeds (70-80mph) are fine. This has been shown to be very effective. I think steady speeds at highway are better than full throttle/high RPM applications due to the different combustion modes the DI engines have and some of these modes block of the EGR.
 
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It does not matter what you put in the tank, the fuel does not go past in the intake valve in a DI engine, but crud sucked through the PCV is.

Spraying slight bits of water or italian tuneups seem to be good ideas.

DI engines usually have higher compression right? I'd be concerned about using something like seafoam in a higher compression engine!
 
They have BG Chem tool but the best addy for keeping carbon out is NOT to drive it.
if you use any carbon dislodging addy, you will probably clog up stuff down the line.
remember, the hardest thing for an engine is to run when cold, so stop making short run throughout the day and make a long run,
 
Originally Posted By: SEMI_287
PCV catch can perhaps?


Catch cans do not help. Plenty of proof of that showing they do not help.
 
Originally Posted By: Miller88
It does not matter what you put in the tank, the fuel does not go past in the intake valve in a DI engine, but crud sucked through the PCV is.


that isn't completely true. gas cleaners indirectly do help. The crud coming through the PCV comes from highly volatile oil. The oil becomes increasingly volatile due to fuel dilution. Using fuel system cleaners to keep the combustion chamber clean and the injectors clean, helps to insure better combustion and a more complete burn. This helps reduce the fuel that makes it to the oil and helps preserve oil quality and reduce PCV vapors.
 
Originally Posted By: horse123
So top tier gas is the best way?


Quality fuel with high detergent levels is probably a good idea. Cheap fuels and regular use of cleaners can probably do as well.
 
Originally Posted By: horse123
^ obvious spam account is obvious


Hi I have contacted the administrator of this site explaining what had happened, I DO NOT have to explain to you, either believe or not DO NOT accuse me of something I have never been EVER on ANY forum and I have been around the internet for 20 years using the same name, google me and then come back and apolagise.

PS
I love it you ask for help then accuse people who have spent their time trying to help of lying. Your best bet is to ignore what everyone says ans go wreck you car in you own way that way you will have no one else to blame.
One thing for sure I wouldn't type another letter to help you even if you were on fire!
 
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You have to admit the post reads exactly like a shill. I've never heard anyone give so much detail when they're just backing a product they use.

Anyway. Top tier gas has always been my thing and it will continue to be so.
 
Originally Posted By: horse123
You have to admit the post reads exactly like a shill. I've never heard anyone give so much detail when they're just backing a product they use.

Anyway. Top tier gas has always been my thing and it will continue to be so.


It sure struck me that way. I'm glad the link was taken down. Kudos to the mods!
 
No experience on the DI engines. Best I ever used on normal FI engines was BG44K. I had always used normal techron (black bottle) a couple times/year and never noticed any improvement. I figured it was just already clean as new and I was maintaining. I tried the BG on the same vehicle at about 100k. Idled smoother, more power, better fuel economy (when driven "normal"). Recommended to family and friends and they experienced the same.

After cleaning (and BG lube in the tranny) the car was fun to drive again so mileage went down, but redline has that effect!

Both cars now have had BG44k at least once/year and recently the gumout regane's recommended here at BITOG. No difference in mileage or power (maybe again that I've maintained clean).

The last couple months, I've been doing the TCW3/MMO but haven't noticed any difference in noises/smoothness/fuel economy. Others experience on here has been different and if/when I get a DI motor that will probably the route I go. For me I'll probably finish the TCW3 I have and just do some BG or Regane 1-2x/year.
 
The best detergent to keep carbon at bay is PEA. That detergent additive actually will travel with combustion gases and clean a bit down stream of combustion so it makes sense that PEA will make its way onto those valves indirectly and clean at least modestly.
 
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2012 Audi A7 3.0T. Recently they sent out a notice about a warranty extension because of excessive carbon buildup on various parts of the engine.
Which parts? Anything needs to actually hit that carbon, and you need to know the location of the problem.

Does anything actually help? Or is manual cleaning the only way to correct it until they invent better parts or whatever will actually cure the cause of the problem?

I understand the letter to say, "Audi has determined that, under certain driving conditions, carbon buildup can occur in the engine cylinder head secondary air ports.

...

In our continuing efforts to assure proper performance of Audi vehicles, your dealer will diagnose and, if necessary, clean the engine cylinder head secondary air ports to remove the carbon buildup at no cost to you as long as the vehicle remains within the time and mileage limits of this warranty extension.

...

This warranty extension covers only the diagnosis and cleaning of the engine cylinder head secondary air ports to remove carbon buildup. And should you ever sell the vehicle, this warranty extension is fully transferable to subsequent owners."


If the technician has to remove parts and physically clean them, forget about spending any money on snake oil to add to your gas. Or spend all you want. It won't make any difference to the engine.
 
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