SeaFoam M278 to avoid DI carbon buildup?
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Super Member
Joined: Feb 2012
Posts: 685
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2012 w221
SeaFoam M278 to avoid DI carbon buildup?
This question is for all you experienced vets, is it advisable to to run seafoam (mild detergent) in the oil to keep the buildup from happening and cleaning whatever has built up so far ?
I am concerned about carbon build up over time and would like to do some sort of precautionary maintenance, like seafoam, to avoid it.
Looking forward to the insights from fellow members, Thanks.
I am concerned about carbon build up over time and would like to do some sort of precautionary maintenance, like seafoam, to avoid it.
Looking forward to the insights from fellow members, Thanks.
MBWorld Fanatic!
Joined: Nov 2014
Posts: 4,242
Likes: 628
From: Chicago burbs
2015 S550
Most Benz dealers offer fuel injection cleaning services. Many recommend it every 3 years or 30k miles.
Motorvac is one that has always had great results. My local indy charges $140 for the service and it makes the pistons, fuel injectors, ports and everything else that the fuel runs through after the fuel filter look almost brand new. It also helps clean out the Catalytic converter.
I saw a video they did on a customer's Toyota Camry where they took a scope to the pistons and ports before running the Motorvac fluid through it. They were loaded in carbon. The car was running at significantly lower than normal compression in 3 of the 4 cylinders...and slightly below in the 4th. After running Motorvac, they did the scope again and it made everything look brand new. It also brought compression back to factor specs.
From everything I've read and seen, none of the fuel additives alone do very much to clean the fuel system. Running gas like Shell that already has the Techron additive probably will help over time and save money, but nothing that would be seen or felt in the short term.
The best way to address your fuel system would be to run something like the Motorvac service, then only use Top Tier gas, which should keep your fuel system in good shape.
Motorvac is one that has always had great results. My local indy charges $140 for the service and it makes the pistons, fuel injectors, ports and everything else that the fuel runs through after the fuel filter look almost brand new. It also helps clean out the Catalytic converter.
I saw a video they did on a customer's Toyota Camry where they took a scope to the pistons and ports before running the Motorvac fluid through it. They were loaded in carbon. The car was running at significantly lower than normal compression in 3 of the 4 cylinders...and slightly below in the 4th. After running Motorvac, they did the scope again and it made everything look brand new. It also brought compression back to factor specs.
From everything I've read and seen, none of the fuel additives alone do very much to clean the fuel system. Running gas like Shell that already has the Techron additive probably will help over time and save money, but nothing that would be seen or felt in the short term.
The best way to address your fuel system would be to run something like the Motorvac service, then only use Top Tier gas, which should keep your fuel system in good shape.
Member
Joined: Nov 2007
Posts: 204
Likes: 18
From: Connecticut
2018 E400 Coupe | 2021 Volvo XC40 Recharge
The prior answers given apply to port injected engines but do not apply to Direct injection. DI injects fuel directly into the cylinder at high pressure so the back of the intake valves dont see an air/fuel mixture flowing from the port. This means that any fuel additive will be unable to have a valve cleaning effect with a DI engine.
The carbon build up on DI engines is attributed to oil vapors from the pcv system accumulating on the back of the hot intake valve. I had a BMW with the twin turbo 6, and this issue was only resolved by a direct physical periodic cleaning of the valves, by removing the intake and cleaning the valves( the BMW recommended solution used a walnut shell abrasive spray cleaning and they had a specific machine to do this).
There was no additive nor any other solution ( catch can for pcv vapors, oil additive, fuel additive) that was well documented to work in preventing this issue. On the BMW motor, there was a fair amount of accumulation at 60,000 miles and if you were picky you might have it cleaned ($400-$800). There was only a documented modest improvement in horsepower but many claimed it ran smoother after cleaning, although this could easily be a placebo effect.
I believe only Lexus includes port injectors on their DI motors so that would be an exception to this.
I'm not seeing any complaints of carbon buildup for the m278 so maybe this is not an issue on this engine.
I would be careful about adding a solvent to your oil, even seafoam recommends a small amount and changing your oil soon afterwards. I'm certain if it resulted in any engine or turbo bearing issues and it was found there was a solvent in your oil, your warranty would be voided.
The carbon build up on DI engines is attributed to oil vapors from the pcv system accumulating on the back of the hot intake valve. I had a BMW with the twin turbo 6, and this issue was only resolved by a direct physical periodic cleaning of the valves, by removing the intake and cleaning the valves( the BMW recommended solution used a walnut shell abrasive spray cleaning and they had a specific machine to do this).
There was no additive nor any other solution ( catch can for pcv vapors, oil additive, fuel additive) that was well documented to work in preventing this issue. On the BMW motor, there was a fair amount of accumulation at 60,000 miles and if you were picky you might have it cleaned ($400-$800). There was only a documented modest improvement in horsepower but many claimed it ran smoother after cleaning, although this could easily be a placebo effect.
I believe only Lexus includes port injectors on their DI motors so that would be an exception to this.
I'm not seeing any complaints of carbon buildup for the m278 so maybe this is not an issue on this engine.
I would be careful about adding a solvent to your oil, even seafoam recommends a small amount and changing your oil soon afterwards. I'm certain if it resulted in any engine or turbo bearing issues and it was found there was a solvent in your oil, your warranty would be voided.
Last edited by MrRat; Oct 1, 2015 at 10:43 AM.
