Carbon buildup?

[RjRacing]

Why is this still on thier website then?

 

[Jeremy1976]

I'll just wait to see once the car is here whether it has MPI or not. Seems there is a lot of misinformation and rumors out there.

 

[Zach L]

They should have put dual injection on all of the new EA888 Gen 3 engines.

My mk6 at 75k miles was showing no symptoms of carbon of build up.

Showing 'no symptoms' does not mean your valves have no carbon build up. I promise you they do, just as the valves on my car do, even after manually scrubbing them twice. I've cleaned valves on about six Mk5/6 engines, including my own. Some of the cars not showing symptoms had worse buildup then those with symptoms. The effect is blocking air flow and causing air turbulence. This may or may not cause a rough idle or starting hesitation, but it will doubtlessly reduce air flow and create turbulence to the air charge, causing a less efficient combustion and reducing power, even if one does not "feel" anything.

This is the case on EVERY car without port injection, including the new US-spec Mk7 1.8T 16v and 2.0T in the US Golf and Golf GTI models which use only direct injection. It seems the US-spec Golf R will not have dual injection (MPI) either. The Euro-spec 2.0T in the Golf GTI and Golf R use MPI, both port and direct. The intended purpose is emissions related, but a side benefit of fuel running across the intake valves is they'll stay clean. So running high quality gasoline with cleaner additives, such as Shell V-power or Chevron Techron, will keep the intake valves clean in the Euro-spec EA888 Gen 3 2.0T engine.

Even when using a catch can, an engine with only direct injection will still have build up. The catch can will only filter about 80% of solid contaminants before routing the PCV gases back into the engine. BTW, the PCV inlet is pre-turbo, so what ends up on your valves also went through the turbo and the entire charge plumbing including the intercooler. Every time I disconnected hoses from the intercooler (lowest point in charge piping system), I could pour out a dirty, oily liquid. Even on cars with catch cans.

So will venting PCV to atmosphere, or routing PCV to the exhaust eliminate carbon build up? The answer is no, and it has been proven from my car and many others running such setups where absolutely NO gas from PCV is put back into the engine. The build up occurs from oil weeping down from the valve seals. The build up is much slower, and not as chunky when the buildup happens solely by this method. Venting PCV to atmosphere or routing to the exhaust is still a benefit because no PCV gases flow through the intake charge piping keeping the turbo, piping and throttle body all cleaner, along with no oily liquid sitting in the intercooler. The additional benefit of routing to the exhaust is it creates a slight vacuum on the crankcase, which helps reduce oil acidity by evacuating volatile crankcase gases (combustion blow-by and atomized fuel molecules) more quickly. Vacuum in the crankcase also helps seal piston rings, reducing the amount of blow-by and increasing power. Many drag cars vent crankcase to exhaust just for this vacuum and corresponding increase in power.

For direct injection engines, SeaFoam does nothing but create a bunch of smoke. It does NOT clean the valves and this has been proven through before/after pics of actual valves. Professional chemical treatments like BG Induction Service will make a minimal impact, as proven by this overly optimistic video HERE.

For an engine with ONLY direct injection - the only way to get the valves truly clean is to scrub them by hand:

 

[Jeremy1976]

How hard is it to do yourself? I know it depends on your mechanical ability and such. But for an average guy that has some logic.

 

[Zach L]

How hard is it to do yourself? I know it depends on your mechanical ability and such. But for an average guy that has some logic.

It's easy, but it takes time because the valves need to be soaked in chemical cleaner for a long time before scrubbing them. Some of the build up is gooey and some of it is rock hard. I pour B12 Chemtool in the intake ports and forget about it for a few hours while they soak. There will always be at least one cylinder with the valves open, so you can only do up to 3 cylinders at a time, then you have to rotate the crank to do the final 4th cylinder. From a cost standpoint, it's a cheap process. Some zip ties, bore/pipe cleaners, few bottle of B12. You'll also want to buy a hook/pick set (like pic below) to clean at the top area of the valve stem where it goes into the valve guide. I'd recommend giving yourself the weekend if you have never removed the intake manifold before. Also, if you plan to work on ANY Volkswagen, make it easy on yourself by picking up a Bentley manual for the car in electronic or hard copy.

 

[George Smooth]

I own a company that specializes in cleaning carbon build up and have seen over 5000 ports on various models.
The TFSI motor built carbon very fast. As low as 50,000km there was major build up. The TSI motor in the MK6 built much slower. At around 75,000km to the eye it does not look so bad. When I got the first TSI in I was hesitant to clean it as the customer would get no value. Upon opening the valves I noticed the crust formed close to the valve seat was creating a negative venturi causing the flow around the valve to reverse toward the stem.
Overall the cleaning of the cars are a must. I do not recommend a scrubbing and if you have to apply carb cleaner with caution ensuring the valves are closed completely. If the chemical gets past the valves and runs down the cylinder wall it can wash away carbon that has formed and go past the rings. This gap similar to a rain drop running down a window may result in oil consumption or in worse cases lost compression. Audi used this technique on the RS4's locally to me soaking the valves overnight resulting in two motors having to be replaced.
The US is full of BMW guys that do walnut shell blasting at reasonable prices. This give you the best result and I am sure they would look at doing VW's.

Here is a picture of a proper clean.

 

[George Smooth]

It's easy, but it takes time because the valves need to be soaked in chemical cleaner for a long time before scrubbing them. Some of the build up is gooey and some of it is rock hard. I pour B12 Chemtool in the intake ports and forget about it for a few hours while they soak. There will always be at least one cylinder with the valves open, so you can only do up to 3 cylinders at a time, then you have to rotate the crank to do the final 4th cylinder. From a cost standpoint, it's a cheap process. Some zip ties, bore/pipe cleaners, few bottle of B12. You'll also want to buy a hook/pick set (like pic below) to clean at the top area of the valve stem where it goes into the valve guide. I'd recommend giving yourself the weekend if you have never removed the intake manifold before. Also, if you plan to work on ANY Volkswagen, make it easy on yourself by picking up a Bentley manual for the car in electronic or hard copy.

ECS Tuning also sells the right tool to remove the intake manifold bracket bolt which saves a lot of time.

 

[Jeremy1976]

Thanks guys!

 

[Zach L]

Overall the cleaning of the cars are a must. I do not recommend a scrubbing and if you have to apply carb cleaner with caution ensuring the valves are closed completely. If the chemical gets past the valves and runs down the cylinder wall it can wash away carbon that has formed and go past the rings. This gap similar to a rain drop running down a window may result in oil consumption or in worse cases lost compression. Audi used this technique on the RS4's locally to me soaking the valves overnight resulting in two motors having to be replaced.
The US is full of BMW guys that do walnut shell blasting at reasonable prices. This give you the best result and I am sure they would look at doing VW's.

Walnut shell blasting is a very good option. What is important is that people understand there must be at least some kind of abrasive action to clean the valves, whether scrubbing or blasting. A chemical spray alone (SeaFoam, BG Cleaning) will NOT be enough. Even cars that are running methanol injection all the time still have carbon build up - there are photos on GolfMkV.com proving this on a VW engine that always runs meth.

Unfortunately, most people do not have the option of doing walnut shell blasting in their home garage as a DIY project. I too used to clean valves as a business for years (even had people drive to me from a different state) and have cleaned all cars using carb cleaner and scrubbing method. I no longer work on any cars besides my personal vehicles. I disagree that scrubbing the valves is bad or harmful to the engine in any way, as I have done this over and over to cars with no issues, including several times to my personal car with 184,000 miles now. One of the cars I cleaned drove over 230,000 miles (370,000 kilometers) before the owner sold it to get a new Golf R. I normally let valves soak about 3 hours. Of course I did not let valves soak overnight, like the dealership you speak of, and I certainly did not attempt to clean a cylinder when the valves were open. Almost everyone cleaning the valves is using carb cleaner and scrubbing. You are the first I have heard suggest that it is harmful, and I'm skeptical to say the least given you have a financial incentive to suggest a different method. I know scrubbing is an effective method to clean the valves, and all evidence I have come across supports it being safe. Maybe the Audi dealership did replace two engines, but dealerships replace engines all the time for many different reasons. This is actually more common on the Audi 4.2L V8 than any other VAG engine I know of. Perhaps the tech tried to rush by cleaning the cylinder with the valves slightly open on one cylinder. Or perhaps it was a completely unrelated cause.

I'll continue cleaning my valves with B12 Chemtool and scrubbing because I've found it to be extremely effective and inexpensive. The only downside I have found is the amount of time it takes.

 

[Jeremy1976]

When the dealership did the chemical and scrubbing treatment they gave me a loaner for a couple days. After they were done they did a complete engine flush and oil change.

 

[George Smooth]

Walnut shell blasting is a very good option. What is important is that people understand there must be at least some kind of abrasive action to clean the valves, whether scrubbing or blasting. A chemical spray alone (SeaFoam, BG Cleaning) will NOT be enough. Even cars that are running methanol injection all the time still have carbon build up - there are photos on GolfMkV.com proving this on a VW engine that always runs meth.

Unfortunately, most people do not have the option of doing walnut shell blasting in their home garage as a DIY project. I too used to clean valves as a business for years (even had people drive to me from a different state) and have cleaned all cars using carb cleaner and scrubbing method. I no longer work on any cars besides my personal vehicles. I disagree that scrubbing the valves is bad or harmful to the engine in any way, as I have done this over and over to cars with no issues, including several times to my personal car with 184,000 miles now. One of the cars I cleaned drove over 230,000 miles (370,000 kilometers) before the owner sold it to get a new Golf R. Of course I did not let valves soak overnight, like the dealership you speak of, and I certainly did not attempt to clean a cylinder when the valves were open. Almost everyone cleaning the valves is using carb cleaner and scrubbing. You are the first I have heard suggest that it is harmful, and I'm skeptical to say the least given you have a financial incentive to suggest a different method. I know scrubbing is an effective method to clean the valves, and all evidence I have come across supports it being safe. Maybe the Audi dealership did replace two engines, but dealerships replace engines all the time for many different reasons. This is actually more common on the Audi 4.2L V8 than any other VAG engine I know of. Perhaps the tech tried to rush by cleaning the cylinder with the valves slightly open on one cylinder. Or perhaps it was a completely unrelated cause.

I'll continue cleaning my valves with B12 Chemtool and scrubbing because I've found it to be extremely effective and inexpensive. The only downside I have found is the amount of time it takes.

Let me quote myself: "I do not recommend a scrubbing and if you have to apply carb cleaner with caution ensuring the valves are closed completely." So I am not against it but if its the last option go for it. There are cheap walnut blast tools available from in the US and its something for a enthusiast to look into. On the BMW forums they actually share the tools and even hire them out. Here is a tool that is very inexpensive http://www.harborfreight.com/portable-abrasive-blaster-kit-37025.html
and the shell you need http://www.harborfreight.com/25-lbs-fine-grade-walnut-shell-blast-media-92155.html

When doing the clean with brushes its virtually impossible to get around the rim of the valve or in some cases the back. The rim in turn causes a negative venturi, you can open the valve after the clean and see and its best to remove it if you have a pick as pictured further up. Also when leaving specs of carbon behind it leaves a type of a trap for more fumes to attach against. We have seen it with cars that have had half cleans done.

 

[Zach L]

Believe it or not, the actual Audi-approved method direct from Audi is to use a wad of 35 zip ties bunch in a group and held together by a rubber band or another zip tie in the middle, with the help of soaking the valves in cleaner. Yes, it's a little comical but this was described in an official report sent by Audi to its dealerships.

 

[Zach L]

There are cheap walnut blast tools available from in the US and its something for a enthusiast to look into. On the BMW forums they actually share the tools and even hire them out. Here is a tool that is very inexpensive http://www.harborfreight.com/portable-abrasive-blaster-kit-37025.html
and the shell you need http://www.harborfreight.com/25-lbs-fine-grade-walnut-shell-blast-media-92155.html

Wow! That is very cheap. Thank you so much for posting! For that price I'll absolute be testing this method out when I do my next cleaning.

When doing the clean with brushes its virtually impossible to get around the rim of the valve or in some cases the back. The rim in turn causes a negative venturi, you can open the valve after the clean and see and its best to remove it if you have a pick as pictured further up.

Yeah, I had good luck getting the back side of the valve stems and at the top of the stems by the valve guides by using the hook and pick set in this area more than others. These parts valve stem and guide parts are also submerged in fluid when letting the valves soak, so that makes things much easier.

 

[George Smooth]

Believe it or not, the actual Audi-approved method direct from Audi is to use a wad of 35 zip ties bunch in a group and held together by a rubber band or another zip tie in the middle, with the help of soaking the valves in cleaner. Yes, it's a little comical but this was described in an official report sent by Audi to its dealerships.

Wow.

BMW has the real mcoy. http://www.minitechinfo.com/tsb/attachments/M040311_Carbon_Blaster_Operating_Manual.pdf . I use this product, the N54 metal shoot also fits the TFSI/TSI port openings. There are some guys on N54tech.com that have made inexpensive ones too.

 

[SpeedieGTI]

Wow.

BMW has the real mcoy. http://www.minitechinfo.com/tsb/attachments/M040311_Carbon_Blaster_Operating_Manual.pdf . I use this product, the N54 metal shoot also fits the TFSI/TSI port openings. There are some guys on N54tech.com that have made inexpensive ones too.

I'm a big fan of the show Wheeler Dealers and they swear by this carbon blaster machine that somehow pumps a potent solvent into the motor (via the intake I think) while the motor is running for an hour or more. My local VW dealer does some BG induction service that looks very similar but I don't think they run the car at the same time. Wheeler Dealer claims excellent results with their machine. If such a machine exists why would anyone manually scrub the valves?