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Diesel Engine FAQ's

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Sea Foam® is absolutely safe for your diesel engine when used as directed. Sea Foam® has been the choice of professional diesel technicians for more than 60 years. Sea Foam® Motor Treatment is 100% Petroleum, NOT A CHEMICAL, and therefore is safe to use in all diesel fuel mixtures.

When adding Sea Foam® Motor Treatment (SF-16, SF-128) to dirty oil before changing oil in a diesel engine, add one pint Sea Foam® to 2.5 gallons of Diesel oil, run engine for 30 - 60 minutes then change oil. If adding Sea Foam® to Deisel fuel or through a fuel filter no oil change is needed.

Sea Foam®, when used in Diesel fuel, cleans fuel deposits from the fuel system and carbon from inside the engine safely. It also adds lubrication and controls moisture when added to diesel fuel at one ounce per gallon. Another use for Sea Foam® in Diesel applications is cleaning fuel injectors. This is accomplished by getting engine to operating temperature then shut off. Remove the fuel filter (replace filter if needed.) Empty all diesel fuel from filter or filter housing and fill filter or housing with straight Sea Foam®. Reinstall filter on engine, making sure there is no air in filter. Start engine and let run about two minutes, then shut engine off and let sit about 5 minutes. This is called a “HOT SOAK” letting the Sea Foam® soak into the carbon. After the “hot soak” period, restart the engine and road test, driving aggressively for about 5 miles. This will clean carbon from the injectors and the combustion chamber inside the engine. Sea Foam® can also be used in oil for cleaning the crankcase. Adding Sea Foam® to your oil will clean oil deposits and varnish from your crankcase, free up sticky lifters and clogged oil control rings. Add Sea Foam® to the oil at one pint to 2.5 gallons of oil. Then drive, or run the engine for 30-60 minutes before changing oil.

Sea Foam® is very safe and effective in the ways described above. Most people that own and work on Diesel cars and trucks know that no liquids or sprays should be used through the air intake system of a Diesel engine including cleaners and starting fluids. If this is done to a Diesel engine it can cause major engine damage including Hydro-Lock or uncontrolled engine acceleration known as “RUN AWAY”. Do not add Sea Foam® to the air intake of a Diesel engine!!

If these simple instructions are followed, Sea Foam® will effectively and safely clean your fuel system, injectors and the crankcase when used in Diesel engine applications.

Adding Sea Foam® to your diesel fuel tank provides the following benefits:

  • Adds lubricity to the fuel, protecting moving parts from excessive friction damage
  • Controls moisture in diesel fuel
  • De-gels frozen diesel fuel
  • Cleans fuel residues from your fuel system components
  • Sea Foam® cleans the fuel pump and lubricates the O-rings
  • Sea Foam® cleans the pintle valve in your injectors and restores the injector’s spray pattern (this is where all the power and smoothness comes from in a diesel.)
  • Cleans carbon deposits from the combustion chamber
  • Stabilizes diesel fuel up to 2 years (at average 1 ounce Sea Foam® /gallon diesel)
  • All fuels leave a residue in the system that collect contaminants and hinder proper operation of that system.  Sea Foam® helps keep the system operating properly by making those residues dissolve gently back into a liquid state, allowing those contaminants to be filtered out of the fuel system.
    Yes, Sea Foam® is safe to use as instructed with any diesel fuel recommended by engine manufacturers.  Low Sulfur and Ultra Low Sulfur fuels have lower lubricating characteristics than older high-sulfur diesel fuels, and also tend to absorb atmospheric moisture more readily.  Using Sea Foam® Motor Treatment helps to counteract both of these negative characteristics.  Sea Foam® adds lubrication to limit friction damage that can be caused by these new fuels, and helps control moisture build up.
    Yes - Sea Foam® is great for use as a diesel engine crank case cleaner in conjunction with an oil change.  Sea Foam® dissolves varnish deposits that hold carbon, ash and other contaminants in the oil. Simply add 1 can of Sea Foam® to each 2.5 gallons of oil and run for 30-60 minutes before changing the oil. More contamination will be removed with the dirty oil leading to reduced engine wear between oil changes. The concept is simple - if you start with a cleaner crank case, it will take longer for the oil to become dirty.
    Using blended 5% Bio Diesel with available mandated Low or Ultra Low Sulfur Diesel Fuels does not change the way Sea Foam® Motor Treatment is used.  Sea Foam® Motor Treatment is 100% Petroleum, NOT A CHEMICAL, and therefore is safe to use as instructed in all diesel fuel mixtures.