[Tomnavigator]

E93Dude here are the pictures of my diesel before carbon cleaning. I have before and after EGR valve pictures and before of the intake ports of the head. I got side tracked and did not take after pictures of the intake runners of the head. But, the intake runners were as clean as the after picture of the EGR. Shiny metal. I have included a picture of the intake port of cylinder #6 which was the worst port and the hardest to clean. The ports progressively got worse as you go from cylinder 1 to cylinder 6. As you can see from the picture that the intake of cylinder 6 is about 50 percent plugged. The intake manifold had a fair amount of build up also. However the intake manifold was only about 5 percent plugged because of the size of the passage ways. The main restriction was in the intake ports on the head which is the area to be walnut blasted. I cleaned my intake with oven cleaner and a pressure washer. The buildup started as a greasy thick goo. The oven cleaner removed the oily portion and left a gritty caked on powder. The pressure washer then easily removed the grit. I repeated the process three times until nothing came out of the manifold (meaning it was clean). This was confirmed looking inside the manifold with a light. I cleaned the intake runners on the head using multiple scrappers to remove as much build up as I could then removed the remaining buildup with walnut blasting.

[Wolf 335]

Originally Posted by Tomnavigator

E93Dude here are the pictures of my diesel before carbon cleaning. I have before and after EGR valve pictures and before of the intake ports of the head. I got side tracked and did not take after pictures of the intake runners of the head. But, the intake runners were as clean as the after picture of the EGR. Shiny metal. I have included a picture of the intake port of cylinder #6 which was the worst port and the hardest to clean. The ports progressively got worse as you go from cylinder 1 to cylinder 6. As you can see from the picture that the intake of cylinder 6 is about 50 percent plugged. The intake manifold had a fair amount of build up also. However the intake manifold was only about 5 percent plugged because of the size of the passage ways. The main restriction was in the intake ports on the head which is the area to be walnut blasted. I cleaned my intake with oven cleaner and a pressure washer. The buildup started as a greasy thick goo. The oven cleaner removed the oily portion and left a gritty caked on powder. The pressure washer then easily removed the grit. I repeated the process three times until nothing came out of the manifold (meaning it was clean). This was confirmed looking inside the manifold with a light. I cleaned the intake runners on the head using multiple scrappers to remove as much build up as I could then removed the remaining buildup with walnut blasting.

Wow!

[335dlci]

Yeah I have had a few needing a cleaning like this..

[Tomnavigator]

Just a little more information on my carbon cleaning. My 335D had 90K at the time I did the carbon cleaning. The engine was running OK. However, I was getting occasional MAF error codes. The car kept telling me the MAF was bad and needed replacing because the air flow was not at an expected level. It took me about 1 1/2 to 2 days to do walnut blast my car. But, I had to make my cleaning probes. I did the walnut blasting 3 times to make sure the intake ports (runners) were totally clean. I purchased 25 pounds of fine ground walnut shells not medium ground shells. I read that medium shells can cause flow issues and plugging. I filtered out the carbon from the walnut shells with a window screen and reused the walnut shells three times. My total cleaning used 75 pounds of shells (25 pounds three times). I made several scrapers and scraped all the carbon from the intake ports before I did the walnut blasting. I probably removed slightly over 90 percent of the buildup by scraping. The hardest buildup to remove was right around the valve because the valve stem gets in the way and the heat at the valve cooked the buildup and made it harder.
Sorry about my spelling. I am an engineer and no engineer can spell worth a crap.
Off subject slightly but since we are talking of carbon buildup. All direct injection engines are prone to carbon buildup. In the past, fuel used to be injected in the intake port near the intake valves. The solvent properties of fuel kept carbon buildup from forming. Now almost all engines use direct injection of fuel into the cylinder. Direct injection gives about 10 percent more horsepower and fuel economy. But, no longer keeps the intake ports clean. This results in carbon buildup in the intake ports which typically need cleaning around 100k miles and as soon as 50k in some engines.
Carbon buildup is now an issue with almost all vehicles except for Toyotas. Toyota uses two fuel injectors per cylinder one in the intake port and one direct injector into the cylinder. Toyota does this specifically to prevent carbon buildup. I purchased a 6 cylinder Toyota Avalon right after I did my carbon cleaning on my 335D. One reason I bought the Toyota was because the engine has 12 injectors for the 6 cylinder engine. I am now 68 years old and don't want to be performing any more carbon cleanings in about 10 years from now. The port injectors in the Avalon are used for light load situations and the direct injectors are used during high load and high acceleration situations. I am retired from General Motors (engineer at corvette plant) and get an employee discount on new vehicle purchases. However, I bought a Toyota because of the carbon cleaning issue and my age.

[Wolf 335]

Originally Posted by Tomnavigator

Just a little more information on my carbon cleaning. My 335D had 90K at the time I did the carbon cleaning. The engine was running OK. However, I was getting occasional MAF error codes. The car kept telling me the MAF was bad and needed replacing because the air flow was not at an expected level. It took me about 1 1/2 to 2 days to do walnut blast my car. But, I had to make my cleaning probes. I did the walnut blasting 3 times to make sure the intake ports (runners) were totally clean. I purchased 25 pounds of fine ground walnut shells not medium ground shells. I read that medium shells can cause flow issues and plugging. I filtered out the carbon from the walnut shells with a window screen and reused the walnut shells three times. My total cleaning used 75 pounds of shells (25 pounds three times). I made several scrapers and scraped all the carbon from the intake ports before I did the walnut blasting. I probably removed slightly over 90 percent of the buildup by scraping. The hardest buildup to remove was right around the valve because the valve stem gets in the way and the heat at the valve cooked the buildup and made it harder.
Sorry about my spelling. I am an engineer and no engineer can spell worth a crap.
Off subject slightly but since we are talking of carbon buildup. All direct injection engines are prone to carbon buildup. In the past, fuel used to be injected in the intake port near the intake valves. The solvent properties of fuel kept carbon buildup from forming. Now almost all engines use direct injection of fuel into the cylinder. Direct injection gives about 10 percent more horsepower and fuel economy. But, no longer keeps the intake ports clean. This results in carbon buildup in the intake ports which typically need cleaning around 100k miles and as soon as 50k in some engines.
Carbon buildup is now an issue with almost all vehicles except for Toyotas. Toyota uses two fuel injectors per cylinder one in the intake port and one direct injector into the cylinder. Toyota does this specifically to prevent carbon buildup. I purchased a 6 cylinder Toyota Avalon right after I did my carbon cleaning on my 335D. One reason I bought the Toyota was because the engine has 12 injectors for the 6 cylinder engine. I am now 68 years old and don't want to be performing any more carbon cleanings in about 10 years from now. The port injectors in the Avalon are used for light load situations and the direct injectors are used during high load and high acceleration situations. I am retired from General Motors (engineer at corvette plant) and get an employee discount on new vehicle purchases. However, I bought a Toyota because of the carbon cleaning issue and my age.

Ahhh good ol' Toyota always seems to figure out simple solutions to common problems.

I watched many videos on guys performing carbon cleaning on N54s (non diesel), and in my opinion nothing beats walnut blasting. Like you mentiond its the area around the valves where walnuts really shine. I was lucky enough to have a forum member local to us in Canada do blasting at a very reasonable price that didn’t warrant me buying equipment.

[335dlci]

Originally Posted by grotto

I have had 8 BMW's including 2 M cars since 1990 and none needed carbon cleaning but at the same time they were not direct injection/egr or diesel and were 5 times more reliable in terms on maintenance than the M57. I bough the diesel due to long commute and thank God it was a CPO in 2013 as I suspected these cars would have issues.

Having spent thousands on typical parts that have broken down and needed replacement, I finally had to delete and tune it as I plan to keep it for another few years. Otherwise, I would have sold this M sport variant but really love the power and gas mileage especially now with delete and tune. Carbon cleaning for $2500 seems like such a waste of money for what you get on a car that's worth 10k and most people just sell these cars or don't hold onto them from what i have seen. Kassel recommended carbon cleaning as I started getting smoothness regulator code on injector #3 and zero quantity adaptation on injector #6 while driving back from their facility. I live in DC area and can't drop it off to Kassel as it's inconvenient with no loaners so I'll have to call around and get a more reasonable price on CBU cleaning.

A good cleaning should cost about 1000 to 1500. No less.

[E93Dude]

Depends what part of the country you are in. $1000 seems "fair".

[lnxguy]

Originally Posted by E93Dude

Depends what part of the country you are in. $1000 seems "fair".

For a gasser maybe, not for a diesel.

[E93Dude]

Ah. Good point.

[335dlci]

Originally Posted by E93Dude

Depends what part of the country you are in. $1000 seems "fair".

Any less. Don't do it.

[DirtyDieselDog]

See if that includes new intake gaskets, throttle body and EGR gaskets, and valve cover gasket. Do they remove the valve cover? Injector gaskets? I read you don't need to remove the valve cover, after doing it I'd disagree. Do they prime the fuel pump correctly or just crank it til it starts and call it good. It's a good opportunity to do things while you are at. Vaccum lines and glow plugs / module. Just my 2 cents. These things you don't know if they do or not is why I don't let anyone work on my car.

[Tomnavigator]

I did my carbon cleaning without removing the valve covers. It is harder to get all the buildup off the valves especially #6 cyl if the valve covers are not removed. The walnut blaster probes need to be bent to match the curved intake runner. If I was doing it again, I would do it the same way and not remove the valve cover. I would do this to make sure no walnut shells get in the head. I really made a mess with walnut shells everywhere even though I covered everything with plastic. I apparently did not seal the plastic well enough. Note: If you do not remove the valve cover, it makes getting the carbon buildup from around the valves harder to clean off. But, It can be done. I did it. You can spend extra time removing the valve cover and sealing the heads up tight or you can spend extra time cleaning the very bottom of the intake runner around the valves. Choose where you want to spend your time.

[335dlci]

Originally Posted by Tomnavigator

I did my carbon cleaning without removing the valve covers. It is harder to get all the buildup off the valves especially #6 cyl if the valve covers are not removed. The walnut blaster probes need to be bent to match the curved intake runner. If I was doing it again, I would do it the same way and not remove the valve cover. I would do this to make sure no walnut shells get in the head. I really made a mess with walnut shells everywhere even though I covered everything with plastic. I apparently did not seal the plastic well enough. Note: If you do not remove the valve cover, it makes getting the carbon buildup from around the valves harder to clean off. But, It can be done. I did it. You can spend extra time removing the valve cover and sealing the heads up tight or you can spend extra time cleaning the very bottom of the intake runner around the valves. Choose where you want to spend your time.

It's honestly best to remove the vc.. you probably need to replace that crispy thing anyways if you need cbu cleaning done. AND you can't accurately know when the valves are shut or not.

[DirtyDieselDog]

Removing the valve cover was no time at all tbh in the grand scope. You can't blast the plastic with shells or it can damage it. Really there is no advantage to leaving it on other than trying to justify being lazy. I cleaned taped and put plastic completely over the entire thing. Used an exacto knife to cut out holes as I went and retaped after I finished. Plus like he said above, that gasket needs replaced. And u can be sure the valves are shut. That's why you need to see what your paying for. An extra 500 now could save u 1500 later when the VCG is leaking....

[335dlci]

Originally Posted by DirtyDieselDog

Removing the valve cover was no time at all tbh in the grand scope. You can't blast the plastic with shells or it can damage it. Really there is no advantage to leaving it on other than trying to justify being lazy. I cleaned taped and put plastic completely over the entire thing. Used an exacto knife to cut out holes as I went and retaped after I finished. Plus like he said above, that gasket needs replaced. And u can be sure the valves are shut. That's why you need to see what your paying for. An extra 500 now could save u 1500 later when the VCG is leaking....

Yup

[e90Noobie]

What if someone doesn't have an insane amount of CBU. Would a simple intake cleaner spray work to clean up the intake tract? The reviews for this stuff look pretty good.

https://www.amazon.com/Liqui-Moly-20.../dp/B076ZJWY7D

[335dlci]

Originally Posted by e90Noobie

What if someone doesn't have an insane amount of CBU. Would a simple intake cleaner spray work to clean up the intake tract? The reviews for this stuff look pretty good.

https://www.amazon.com/Liqui-Moly-20.../dp/B076ZJWY7D

No.

[e90Noobie]

Originally Posted by 335dlci

No.

Just not strong enough or is there risk of clogging the injectors?

[335dlci]

Originally Posted by e90Noobie

Just not strong enough or is there risk of clogging the injectors?

It's snake oil.

[e90Noobie]

Originally Posted by 335dlci

It's snake oil.

I'm not so sure that's true. If it's being sprayed directly into the "throttle body" and it's truly a cleaner specifically for carbon then it should at least perform some cleaning. It has a lot of good reviews and liquimoly is a good company.

[335dlci]

Originally Posted by e90Noobie

I'm not so sure that's true. If it's being sprayed directly into the "throttle body" and it's truly a cleaner specifically for carbon then it should at least perform some cleaning. It has a lot of good reviews and liquimoly is a good company.

There is no way a liquid will remove caked on slate.

[loganwamon]

Completely different vehicle here but VW quoted me something like $1400 CAD to perform the cleaning on my Tiguan. I'm not sure if they do walnut blasting though.

On the other hand, a user on here (who I'm still trying to reach) has all the equipment and offers to do the job for $400 or so (with some glowing reviews). I still need to get it done but I'd rather not fork over thousands if I can help it.