sea foam b7
#2
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there are a bunch of videos on you tube that you can watch. 1/3 in gas tank, 1/3 in oil and 1/3 sucked up directly into the engine via a vacuum line.
Here is a good explanation I found off the Planet 9 Porsche web page posted by the "Rockster" - very good write-up:
Direct injection engines attempt to deliver a richer mixture of air:fuel to the combustion chamber but in a small cloud centered around the spark plug.
Away from the cloud there is an excess of air and a dearth of gasoline.
The "rich" cloud delivers better utilization of gasoline and more power, while the air outside of this could provides excess air (oxygen) to the converters. The converters need oxygen to use to process (through chemical reactions) the more harmful exhaust gases into less harmful exhaust gases.
One particularly bad gas is Nox. Nitrogen oxide. If forms in the high temperatures of combustion. To keep this temp down engines are designed to under some operating conditions to allow some mixing of exhaust gases with the fresh incoming charge. Intake and exhaust valve overlap is one such way.
A side effect is some of the cloud and some exhaust gases can flow back into the intake ports and leave deposits on the intake valves. Since fuel injectors are no longer spraying fuel on these surfaces there's nothing to wash these deposits off.
The intake sides of the intake valves are crucial to the proper flow and swirling of incoming air to form the pre-cloud around the spark plug/fuel injector into which fuel will be injected.
Deposits on these intake valve surfaces will affect the proper formation of this cloud and in fact likely lead to even more deposits as the cloud ventures outside of its intended area of existence.
The problem is exacrebated by mainly the way we in USA drive our vehicles. Lots of idling and low rpm useage. Most engines spend their time operating at 30% of throttle or less and under these conditions it is more likely air flow in the combustion chamber will be backwards and purposely so. Over time build up will occur.
Couple of things you can do to help engine:
1) Do not overfill engine with oil. Overfilling causes more oil vapor to get into the crankcase air and more oil vapor to remain in the air that passes through the oil recovery system designed to remove oil from this air on its way to the intake system and combustion chambers. This oil vapor in the air from the crankcase being routed to the intake and combustion chambers contributes to the build up of deposits on the valves.
2) Keep engine oil fresh. Old oil will accumulate water and unburned gas over time and this makes oil more fluid and this results in more oil foaming and more oil foaming results in more oil vapor in crankcause fumes. More oil in these fumes means more oil vapor routed to engine intake and more deposits.
3) Avoid long periods of idling.
3) Use higher engine rpms. Granted this one's tough cause we are all seeking to use lower engine rpms to mainly save fuel. One doesn't have to run engine to redline every shift but any bit of extra engine rpms helps.
Sort of related: A problem developed with VW's diesel engines. VW used exhaust gas recirculation to feed exhaust gases into the intake to essentially pollute the incoming air and lower its oxygen content and thus lower combustion chamber temperature and Nox creation.
The problem was 1) This (diesel) exhaust gas contained soot; 2) This soot mixed with crankcase fumes that contained some oil vapor and the soot and oil combined to in some cases form a hard layer of carbon (soot/oil) in the intake passages that in some cases limit intake air flow into the engine to the point the car would barely run.
The fix was an intake cleaning. That was not covered under warranty.
The solution was to run a good quality diesel engine oil. Change it frequently. Avoid overfilling the engine with oil.
And contrary to what many buyers felt was proper for the engine, to use more rpms, not fewer. Those that attempted to drive the car like a big rig and short shift and keep rpms low, below 2000 and even lower in some cases would find the engine coked up in sometimes 30,000 miles or even less.
OTOH those that followed the above solution -- of which I was one -- found upon inspection while the intake manifold passages had a layer of oil there was no build up and the intake passages were quite open. I drove my VW TDi for over 120,000 miles and never had a problem. Based on the way the woman I sold it too was driving it -- shifting at just 1500 rpms -- I expect it coked up on her pretty quick.
Here is a good explanation I found off the Planet 9 Porsche web page posted by the "Rockster" - very good write-up:
Direct injection engines attempt to deliver a richer mixture of air:fuel to the combustion chamber but in a small cloud centered around the spark plug.
Away from the cloud there is an excess of air and a dearth of gasoline.
The "rich" cloud delivers better utilization of gasoline and more power, while the air outside of this could provides excess air (oxygen) to the converters. The converters need oxygen to use to process (through chemical reactions) the more harmful exhaust gases into less harmful exhaust gases.
One particularly bad gas is Nox. Nitrogen oxide. If forms in the high temperatures of combustion. To keep this temp down engines are designed to under some operating conditions to allow some mixing of exhaust gases with the fresh incoming charge. Intake and exhaust valve overlap is one such way.
A side effect is some of the cloud and some exhaust gases can flow back into the intake ports and leave deposits on the intake valves. Since fuel injectors are no longer spraying fuel on these surfaces there's nothing to wash these deposits off.
The intake sides of the intake valves are crucial to the proper flow and swirling of incoming air to form the pre-cloud around the spark plug/fuel injector into which fuel will be injected.
Deposits on these intake valve surfaces will affect the proper formation of this cloud and in fact likely lead to even more deposits as the cloud ventures outside of its intended area of existence.
The problem is exacrebated by mainly the way we in USA drive our vehicles. Lots of idling and low rpm useage. Most engines spend their time operating at 30% of throttle or less and under these conditions it is more likely air flow in the combustion chamber will be backwards and purposely so. Over time build up will occur.
Couple of things you can do to help engine:
1) Do not overfill engine with oil. Overfilling causes more oil vapor to get into the crankcase air and more oil vapor to remain in the air that passes through the oil recovery system designed to remove oil from this air on its way to the intake system and combustion chambers. This oil vapor in the air from the crankcase being routed to the intake and combustion chambers contributes to the build up of deposits on the valves.
2) Keep engine oil fresh. Old oil will accumulate water and unburned gas over time and this makes oil more fluid and this results in more oil foaming and more oil foaming results in more oil vapor in crankcause fumes. More oil in these fumes means more oil vapor routed to engine intake and more deposits.
3) Avoid long periods of idling.
3) Use higher engine rpms. Granted this one's tough cause we are all seeking to use lower engine rpms to mainly save fuel. One doesn't have to run engine to redline every shift but any bit of extra engine rpms helps.
Sort of related: A problem developed with VW's diesel engines. VW used exhaust gas recirculation to feed exhaust gases into the intake to essentially pollute the incoming air and lower its oxygen content and thus lower combustion chamber temperature and Nox creation.
The problem was 1) This (diesel) exhaust gas contained soot; 2) This soot mixed with crankcase fumes that contained some oil vapor and the soot and oil combined to in some cases form a hard layer of carbon (soot/oil) in the intake passages that in some cases limit intake air flow into the engine to the point the car would barely run.
The fix was an intake cleaning. That was not covered under warranty.
The solution was to run a good quality diesel engine oil. Change it frequently. Avoid overfilling the engine with oil.
And contrary to what many buyers felt was proper for the engine, to use more rpms, not fewer. Those that attempted to drive the car like a big rig and short shift and keep rpms low, below 2000 and even lower in some cases would find the engine coked up in sometimes 30,000 miles or even less.
OTOH those that followed the above solution -- of which I was one -- found upon inspection while the intake manifold passages had a layer of oil there was no build up and the intake passages were quite open. I drove my VW TDi for over 120,000 miles and never had a problem. Based on the way the woman I sold it too was driving it -- shifting at just 1500 rpms -- I expect it coked up on her pretty quick.
#3
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Based on the write-up above I give my audi a constant "Italian Tune-up" by running in the tiptronic mode and letting the RPMs see a little red. Its more fun that way and maybe it helps the carbon. I am also using the chevron techron additive in addition to top tier gas. The audi mechanic I spoke to said he does not see that many carbon issues anyways so I figure I should be ok taking a few preventive steps.
#4
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if you are trying to do this service to help the intake valve carbon buildup, it will not really help. You should look into actual fsi services. There are tools and chemicals out there that are designed to combat this buildup. As far as additives go the only one we ever use here is bg 44k. It helps to soften the buildup, and slows its buildup. We tested this ourselves. It will not remove the buildup though, for that you need a different treatment or to remove the intake manifold and start scrubbing. here is a link for the 44k we use it most cars we service.
http://www.raimotorsport.com/BG-44K-...r-p/bg-208.htm
http://www.raimotorsport.com/BG-44K-...r-p/bg-208.htm
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