carbon cleaning

Jeffs2013GTI said:

Just save your money and get it media blasted at the dealer. My Dealer charges $600 to do it and they recommend every 40K. I think that is a little pre mature, but maybe its just more effective than waiting till your car is throwing codes.

Its just part of maintenance. $600 every 40K miles isn't bad.


Jeff

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This thread isn't for you then. This thread is for people who are interested in doing the media blasting themselves either for financial and\or hobby reasons. I agree 600 isnt to bad which is the avg price for the N54 as well but I prefer to do my own maintenance. Helps me keep an eye on things.

Surferboy120 said:

This thread isn't for you then. This thread is for people who are interested in doing the media blasting themselves either for financial and\or hobby reasons. I agree 600 isnt to bad which is the avg price for the N54 as well but I prefer to do my own maintenance. Helps me keep an eye on things.

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I do my own maintenance and have since my first car, but sometimes, its just better to bite the bullet and have someone do it for you. YOU may be able to do this job, but some guy who THINKS he can because he read your thread could JACK UP his car BAD.

Thats all I am sayin...


Jeff

Jeffs2013GTI said:

I do my own maintenance and have since my first car, but sometimes, its just better to bite the bullet and have someone do it for you. YOU may be able to do this job, but some guy who THINKS he can because he read your thread could JACK UP his car BAD.

Thats all I am sayin...


Jeff

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You are correct in that its a simple DIY "but" if those valves are not shut for each cylinder there will be a whole lot of media in the cylinder and a major cost. Your point is well understood. :thumbsup:

Surferboy120 said:

Super easy mod to the tool. The portion which fits into the intake is a hair to big. Literally you could take a hammer to fit it in as is but obviously that wouldnt be good so its a matter of shaving down a small bit of material to have the tool fit correctly. It can easily be done in a garage and the mod does not impact the function of the tool in any manner. Hope this helps.

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Awesome. I'm looking forward to reading about how effective this is.

Jeffs2013GTI said:

I do my own maintenance and have since my first car, but sometimes, its just better to bite the bullet and have someone do it for you. YOU may be able to do this job, but some guy who THINKS he can because he read your thread could JACK UP his car BAD.

Thats all I am sayin...


Jeff

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This is an enthusiast forum. It's filled with all kinds of information that can lead one to destroying their car if they screw something up. That should not stop us from sharing information like this.

Short drives and lots of throttle changes causes a rich FA mix which is what leaves the gunk on the backs of the valves.

I kinda think a good long drive (3-4 hrs) at 70-75 is good for cleaning a lot of material off the backs of the valves. The fuel mix will lean out, the valves and head will become super heated by the constant run speed and lean mix, and the carbon will begin to atomize off the backs of the valves and possibly from the head ports too.

bebersol said:

Short drives and lots of throttle changes causes a rich FA mix which is what leaves the gunk on the backs of the valves.

I kinda think a good long drive (3-4 hrs) at 70-75 is good for cleaning a lot of material off the backs of the valves. The fuel mix will lean out, the valves and head will become super heated by the constant run speed and lean mix, and the carbon will begin to atomize off the backs of the valves and possibly from the head ports too.

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Actually this is not the case. Here is a good piece of information which helps to explain why. Hope this helps.

The main reason is that fuel and added detergents are not hitting the back of the intake valves. By injecting the fuel directly into the cylinder instead of at the back of the valve, the gasoline and detergents can’t clean the valve and port.

Second, leaner mixtures and higher combustion pressures can make the problem worse over time. A direct fuel injection motor produces more energy from a given amount of fuel and air than a port fuel injection engine. Today’s engines operate on a ragged edge between optimal efficiency and a misfire. There is not much room for error, like hot spots in the combustion chamber or a worn spark plug.

When a hot spot or sub-optimal flame front is created due to turbulent air, the amount of unburned fuel in the combustion chamber increases. When the valve opens during the intake stroke, it might come in contact with these byproducts, and, unlike the exhaust valve, the gases passing by are not hot enough to burn them off.

Third, the intake valve goes into the combustion chamber, regardless of whether it is port fuel injected or direct injected. When it does, for that small period of time, the valve is exposed to combustion byproducts that can stick to its neck. If the previous combustion cycle was less than optimal, the intake valve is exposed.

Some direct-injection vehicles with variable valve timing can expose the valve to combustion byproducts as the valves adjust, which creates a scavenging effect to either pull or leave behind a small amount of exhaust gases in the chamber to control NOX emissions. Also, some turbocharged direct-injection engines will leave the intake and exhaust valves open at the same time in order to keep the turbo spinning to reduce lag.

Really wish there was some sort of affordable aftermarket MPI system for these cars. Like an "aftermarket OEM+" upgrade. If we had MPI like the ROW MK7's, and used quality fuels (Shell V Power for example), this buildup wouldn't be a problem right?

iGTI said:

How would you know your valves are closed?

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If you have to ask, probably better if you take it in and have it done. It will probably be more of a job than you want to tackle. It was for me. I just had mine done a few months ago at AU Tuning in Huntington Beach. It really is the best way to go. They have all the walnut shell blaster stuff and if you have a lot of carbon build up it makes a big difference.

Surferboy120 said:

Third, the intake valve goes into the combustion chamber, regardless of whether it is port fuel injected or direct injected. When it does, for that small period of time, the valve is exposed to combustion byproducts that can stick to its neck. If the previous combustion cycle was less than optimal, the intake valve is exposed.

Some direct-injection vehicles with variable valve timing can expose the valve to combustion byproducts as the valves adjust, which creates a scavenging effect to either pull or leave behind a small amount of exhaust gases in the chamber to control NOX emissions. Also, some turbocharged direct-injection engines will leave the intake and exhaust valves open at the same time in order to keep the turbo spinning to reduce lag.

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Another reason that I've read is that the carbon buildup comes from oil slowly seeping past the intake valve guide seals and down the valve guides. A tiny amount of oil is necessary to lubricate the guides, and that oil eventually ends up burnt on the head of the valve.

red_stapler said:

Another reason that I've read is that the carbon buildup comes from oil slowly seeping past the intake valve guide seals and down the valve guides. A tiny amount of oil is necessary to lubricate the guides, and that oil eventually ends up burnt on the head of the valve.

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Oh yes good one thats part of the equation as well.

Unfortunately the direct injection design is the limitation there just isn't a way to prevent it. Its just a matter of when not if.

bebersol said:

Short drives and lots of throttle changes causes a rich FA mix which is what leaves the gunk on the backs of the valves.

I kinda think a good long drive (3-4 hrs) at 70-75 is good for cleaning a lot of material off the backs of the valves. The fuel mix will lean out, the valves and head will become super heated by the constant run speed and lean mix, and the carbon will begin to atomize off the backs of the valves and possibly from the head ports too.

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I drove from Los Angeles to Yosemite National Park to and from same day. That is about a 5 hour drive one way. The whole way I was doing 75-85. I didn't have a misfire code for like 2 days. 2 days later the code came back. It could maybe alleviate the problem temporarily but it isn't a long term solution.

Before you ask I am too broke right now to get it done and it's something I would rather get done by a professional who has all the proper tools.

Thanks everyone, This has been a great discussion.

Would it be safe to assume that this has always been a problem with diesel too because of the DI design?

I wonder how often big rigs that primarily run the highway require carbon cleaning?

bebersol said:

Thanks everyone, This has been a great discussion.

Would it be safe to assume that this has always been a problem with diesel too because of the DI design?

I wonder how often big rigs that primarily run the highway require carbon cleaning?

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Its a huge issue for diesel trucks mainly because they have less detergents in their fueling than we do. If you look online there have been many studies showing an avg of 10% loss in power per 10,000 miles. There is no magic to carbon buildup you just have to clean them.

Surferboy120 said:

Its a huge issue for diesel trucks mainly because they have less detergents in their fueling than we do. If you look online there have been many studies showing an avg of 10% loss in power per 10,000 miles. There is no magic to carbon buildup you just have to clean them.

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Port Injection + Direct Injection does the trick that or water meth