Carbon Buildup @ 80k - Before and After Photos

[Wrath And Tears]

I think I read that in another thread, if that was you. Still, I have my doubts that carbon buildup causes misfires. But I'm no VW dealer..

Carbon absolutely causes misfires. When it gets bad enough it prevents the valve from fully seating, and also blocks the flow of air into the cylinder.

 

[jimlloyd40]

Carbon absolutely causes misfires. When it gets bad enough it prevents the valve from fully seating, and also blocks the flow of air into the cylinder.

Absolutely true.

 

[Stija]

Carbon absolutely causes misfires. When it gets bad enough it prevents the valve from fully seating, and also blocks the flow of air into the cylinder.

While i agree that carbon buildup on valves can be preventing proper seating and closure of it i am not certain it will only cause misfires. Furthermore this cleaning never addresses this problem of seating as the valves are closed during cleaning, so areas that seat into the head are never cleaned, so this argument is moot.

Perhaps his tune is the cause of misfires, perhaps a multitude of other reasons, last of which in my opinion is carbon buildup.

 

[Hoon]

Perhaps his tune is the cause of misfires, perhaps a multitude of other reasons, last of which in my opinion is carbon buildup.

Your opinion is based on nothing and is directly contrary to what VW, any VW dealer, or any reputable Euro shop has determined through real world experience.

https://www.shopdap.com/blog/post/carbon-build-up-and-cold-start-misfires-on-2-0t-tsi.html

 

[Stija]

Your opinion is based on nothing and is directly contrary to what VW, any VW dealer, or any reputable Euro shop has determined through real world experience.

https://www.shopdap.com/blog/post/carbon-build-up-and-cold-start-misfires-on-2-0t-tsi.html

And that blog/link you posted makes it factual and real. The first paragraph says that cold star misfires could be due to the carbon buildup, hows that different that me saying it most likely isnt due to carbon buildup?

Perhaps it is, perhaps its not. My money is on the latter. We will find out which one it is in this instance only soon enough i hope.

Can we at least agree that areas of valves that seat into the head are NOT cleaned by this method because the valves are seated closed during this procedure? To me this is the most critical contact point that needs to be cleaned, and this method doesnt do anything as far as that goes.

 

[Wrath And Tears]

And that blog/link you posted makes it factual and real. The first paragraph says that cold star misfires could be due to the carbon buildup, hows that different that me saying it most likely isnt due to carbon buildup?

Perhaps it is, perhaps its not. My money is on the latter. We will find out which one it is in this instance only soon enough i hope.

Can we at least agree that areas of valves that seat into the head are NOT cleaned by this method because the valves are seated closed during this procedure? To me this is the most critical contact point that needs to be cleaned, and this method doesnt do anything as far as that goes.

They are cleaned while doing this method, just not by the walnuts. You do it by hand.

I personally have fixed lots and lots of random misfires and cold start misfires by performing carbon cleanings. So I will happily take your money. I've been using the ATS 3C lately and while quite scary at first, really cleans out the carbon.

While i agree that carbon buildup on valves can be preventing proper seating and closure of it i am not certain it will only cause misfires. Furthermore this cleaning never addresses this problem of seating as the valves are closed during cleaning, so areas that seat into the head are never cleaned, so this argument is moot.

Perhaps his tune is the cause of misfires, perhaps a multitude of other reasons, last of which in my opinion is carbon buildup.

Just curious what else you think it would cause? I mean long term you would see fuel trim issues and stuff, but the CEL would come on with random misfires long before that. It happened with a 2010 A3 that my shop was working on. Other tech's replaced spark plugs, coils, and even the timing chains because they were stretched. It still had intermittent random misfires. I scoped the cylinder, saw the carbon build up on the valves and did a carbon cleaning. That was 6 months ago or so. It just came back for service recently and it was problem free since the cleaning.

 

[Mrc5z]

They are cleaned while doing this method, just not by the walnuts. You do it by hand.

I personally have fixed lots and lots of random misfires and cold start misfires by performing carbon cleanings. So I will happily take your money. I've been using the ATS 3C lately and while quite scary at first, really cleans out the carbon.

The ATS 3C works good ? My local shop has that and even though we viewed the valves with the camera it looked skeptical for cars that have a lot of build up. Thinking a can of CRC would’ve done the same for light coating of carbon

 

[Wrath And Tears]

The ATS 3C works good ? My local shop has that and even though we viewed the valves with the camera it looked skeptical for cars that have a lot of build up. Thinking a can of CRC would’ve done the same for light coating of carbon

For heavy build up you need to run the 3C twice according to the manual. For the cars that I have used it on, it has worked great. The slight stumbling and hesitation right off idle was instantly gone, as well as the valves looking great.

There is a lot that goes into using the machine and you have to follow the instructions exactly otherwise it won't work as good if at all. Like for the VW/Audi engines you need to open up the flaps in the intake manifold and keep them fully open the whole cleaning. Making sure you chill the chemicals before hand and starting the cleaning on a cold engine also help.

I've never used the CRC stuff before, but they are a great company (I've used their other cleaning products before), so I can't compare the two. I can tell you it sure beats pulling the intake manifold and walnut blasting the valves.

 

[Stija]

For heavy build up you need to run the 3C twice according to the manual. For the cars that I have used it on, it has worked great. The slight stumbling and hesitation right off idle was instantly gone, as well as the valves looking great.

There is a lot that goes into using the machine and you have to follow the instructions exactly otherwise it won't work as good if at all. Like for the VW/Audi engines you need to open up the flaps in the intake manifold and keep them fully open the whole cleaning. Making sure you chill the chemicals before hand and starting the cleaning on a cold engine also help.

I've never used the CRC stuff before, but they are a great company (I've used their other cleaning products before), so I can't compare the two. I can tell you it sure beats pulling the intake manifold and walnut blasting the valves.

So let me get this straight, with your ATS 3C machine it is all done by liquid without pulling the intake, so again, how does the area on valve bodies where it seats against the cylinder head get cleaned? The contact ring on the valve that touches the seat in the cylinder.. how do you address that?

Also, since I don't seem to understand how carbon buildup can cause misfires, could you please explain it like I am a five year old? Or point me to an explanation of why the problem happens in theory, not practical solutions to cleaning carbon deposits. From what I have read (minimal search) it seems that the theory is that carbon buildup restricts air flow which in turn causes issues. I get that in theory it is restricting of airflow, but that is a negligible amount of restriction, and accepting it as the cause, how does the same restriction solve itself after car warms up for example? If its a restriction issue it is a restriction issue whether car cold or warmed up no? Yet misfire seems to correlate with cold startups mostly..

 

[Wrath And Tears]

So let me get this straight, with your ATS 3C machine it is all done by liquid without pulling the intake, so again, how does the area on valve bodies where it seats against the cylinder head get cleaned? The contact ring on the valve that touches the seat in the cylinder.. how do you address that?

Also, since I don't seem to understand how carbon buildup can cause misfires, could you please explain it like I am a five year old? Or point me to an explanation of why the problem happens in theory, not practical solutions to cleaning carbon deposits. From what I have read (minimal search) it seems that the theory is that carbon buildup restricts air flow which in turn causes issues. I get that in theory it is restricting of airflow, but that is a negligible amount of restriction, and accepting it as the cause, how does the same restriction solve itself after car warms up for example? If its a restriction issue it is a restriction issue whether car cold or warmed up no? Yet misfire seems to correlate with cold startups mostly..

The ATC 3C injects 3 liquid chemicals while the car is running, so it cleans the valves in the same way that MPI does. Any air restriction to a valve is not considered negligible.

During a cold start, the car is not in fuel control until the oxygen sensors warm up enough. Then the car goes from open loop, to closed loop and can control how much fuel it needs to inject. Thus the misfires disappear because the car can compensate. What ends up happening is that the car over fuels at cold start.

For combustion to happen, you need three things. Spark, air and fuel. If anyone of these things is not present in the proper amount, you can have incomplete combustion. Incomplete combustion is also known as a misfire.

There are several different types of misfires. The one most people feel is a dead miss, where no combustion happens at all. The computer however is sensitive enough to tell when some combustion happens but isn't a complete combustion, and will log misfires. These misfires have to occur frequently enough to trigger a check engine light, otherwise you have to log them to see the misfires.

Let me know if you need anything else explained.

 

[Stija]

The ATC 3C injects 3 liquid chemicals while the car is running, so it cleans the valves in the same way that MPI does. Any air restriction to a valve is not considered negligible.

During a cold start, the car is not in fuel control until the oxygen sensors warm up enough. Then the car goes from open loop, to closed loop and can control how much fuel it needs to inject. Thus the misfires disappear because the car can compensate. What ends up happening is that the car over fuels at cold start.

For combustion to happen, you need three things. Spark, air and fuel. If anyone of these things is not present in the proper amount, you can have incomplete combustion. Incomplete combustion is also known as a misfire.

There are several different types of misfires. The one most people feel is a dead miss, where no combustion happens at all. The computer however is sensitive enough to tell when some combustion happens but isn't a complete combustion, and will log misfires. These misfires have to occur frequently enough to trigger a check engine light, otherwise you have to log them to see the misfires.

Let me know if you need anything else explained.

Thanks for elaborating on using the machine, i didnt understand how it works.

The rest i agree with. I just fail to see still how some amount of carbon buildup can cause enough of an air restriction, to what, cause the misfire? I just dont follow, i see what you’re saying, just dont agree its the air restriction.

I have a different theory slightly. If we assume that this mostly happens on tuned cars or cars which have been mehanically modified, then the airflow (among other things) at open loop isnt what it used to be when car was oem mechanically, so it misfires.

Then once warmed up we agree about closed loop compensating for mechanical changes, ie airflow, bigger injectors/pulp perhaps, etc. (not even getting into guys running e20-30 or “custom mixes”)

Furthermore, to add, if air flow was so severely compromised to cause open loop misfires and requiring closed loop compensations, one should feel the loss of power (less air) or slight power increase (more air) post cleaning. You cant convince me that airflow can be impaired to cause a misfire but no power loss.. we can argue about degree of loss, but less air means less power.

 

[Wrath And Tears]

Thanks for elaborating on using the machine, i didnt understand how it works.

The rest i agree with. I just fail to see still how some amount of carbon buildup can cause enough of an air restriction, to what, cause the misfire? I just dont follow, i see what you’re saying, just dont agree its the air restriction.

I have a different theory slightly. If we assume that this mostly happens on tuned cars or cars which have been mehanically modified, then the airflow (among other things) at open loop isnt what it used to be when car was oem mechanically, so it misfires.

Then once warmed up we agree about closed loop compensating for mechanical changes, ie airflow, bigger injectors/pulp perhaps, etc. (not even getting into guys running e20-30 or “custom mixes”)

Furthermore, to add, if air flow was so severely compromised to cause open loop misfires and requiring closed loop compensations, one should feel the loss of power (less air) or slight power increase (more air) post cleaning. You cant convince me that airflow can be impaired to cause a misfire but no power loss.. we can argue about degree of loss, but less air means less power.

All of my experience is with stock cars. There will indeed be power loss reguardless of being stock or modded. How much? I can't say. Not everyone uses 100% throttle all the time. Modded people might not notice it if they don't go WOT, or maybe they do and just haven't commented on it. Maybe they looked elsewhere first.

Then you also have to consider how compressed air works. Under WOT with boost, the restriction might not become an issue. If the car was NA, then certainly you would notice the power loss, but boost works completely differently.

It would take an engineer and lots of testing to give you an answer on that. Lack of evidence (of loss of power in this case) cannot be used to prove a point one way or the other.

 

[Stija]

So? It’s been almost a month and I’m inpatient, has it cured your misfire on idle?

 

[jcw122]

Sorry for the lack of an update. It's now been 3 months and I CAN CONFIRM that per my OBDeleven, I have not had any misfires since the cleaning!

I'm pretty thrilled, and I think this means that for my specific car, the carbon was 100% causing the misfires and the cleaning fixed it. I'm now at approximately 83k miles (3k miles after cleaning).

So? It’s been almost a month and I’m inpatient, has it cured your misfire on idle?

 

[eajr]

Sorry for the lack of an update. It's now been 3 months and I CAN CONFIRM that per my OBDeleven, I have not had any misfires since the cleaning!

I'm pretty thrilled, and I think this means that for my specific car, the carbon was 100% causing the misfires and the cleaning fixed it. I'm now at approximately 83k miles (3k miles after cleaning).

I had severe.misfires starting at 45k. I changed the plugs and coils, even tried a fuel injector cleaner. I was even going into limp mode at times and had a very rough idle. My dealer removed the carbon and now car is running like new.