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How To Use Sea Foam Motor Treatment: 3 Ways To A Cleaner Fuel System

how to use Sea Foam

Sea Foam motor treatment

Over time, the internals of your engine can get clogged up with all kinds of nasty stuff. Inside the crankcase, where the oil lives, varnish and tar build up on the surfaces of the pistons, rings, lifters, and in the oil galleys that supply the oil to all the components. Oil can’t flow as easily to where it needs to go. This reduces the engine’s ability to cool and lubricate itself, reducing the efficiency, performance, and life of the engine.

The same build up occurs inside the fuel system as well, clogging the injectors or carburetor jets, gumming up the intake valves and on the tops of the pistons too. If the valves don’t move freely, then your engine’s breathing is greatly hampered. Carbon deposits on the pistons and valves can lead to hot spots which cause detonation, which lowers your engine’s performance. Carbon can also build up in places along the engine intake tract making for reduced and turbulent air flow. The trick is how do you clean these hard-to-reach places in your engine? Virtually every engine, from 2-stroke lawnmowers, to boat engines, to big rig diesels face the same problem. But there are ways to keep things clean inside your engine. Let’s take a look at Sea Foam Motor Treatment and how it can benefit your engine.

What Is Sea Foam?

Sea Foam has been around for over 70 years, and it is one of the most trusted treatments for all engines. While Sea Foam makes a range of excellent products, the main one is Sea Foam Motor Treatment. Sea Foam is specially formulated to safely and slowly re-liquify the gum, sludge, varnish and carbon deposits from the hard parts in your engine so they can be flushed out of the system.

Sea Foam helps lubricate the moving parts, particularly in the fuel system. Ethanol additives dry out the seals and leaves a varnish that makes it harder for oil to lubricate the parts. Removing this varnish brings the engine back into top working order. Inside the fuel tank, Sea Foam absorbs water, allowing it to be burned up in the combustion chamber without issue.

How To Use Sea Foam

When deciding how to use Sea Foam Motor Treatment there are three options: in the crankcase, in the fuel tank, and in the diesel fuel filter. For cleaning the top end, use Sea Foam Spray as directed as it is no longer recommended to apply liquid Sea Foam directly into the intake tract. Sea Foam spray is a much better method for top end cleaning, as you will see later on.

Using Sea Foam In The Crankcase

When added to the oil, Sea Foam will clean up sludge, quiet noisy lifters, and remove oil varnish. One can treats 16 quarts of oil so you get two treatments in one can for most vehicles. The best method is to add the treatment 500-1,000 miles before the next oil change, and then add the rest after you have changed the oil. This will get the big amounts of varnish and sludge out, and the second treatment keeps things clean.


Pop the cap on the oil filler neck. You can add Sea Foam before or after an oil change.
Pop the cap on the oil filler neck. You can add Sea Foam before or after an oil change.
Pour up to 1 ounce of Sea Foam per quart of oil into the engine. We used about ½ of the bottle.
Pour up to 1 ounce of Sea Foam per quart of oil into the engine. We used about ½ of the bottle.

Using Sea Foam In The Fuel Tank

One can treats up to 16 gallons of fuel. This will remove deposits from the fuel pump, injectors or carb jets, control moisture, and stabilize the fuel. In diesel engines, it will de-ice and has anti-gel properties.

One bottle treats up to 16 gallons of fuel. We poured in 1/2 of the bottle to make this a one-bottle job.
One bottle treats up to 16 gallons of fuel. We poured in 1/2 of the bottle to make this a one-bottle job.

Using Sea Foam In The Diesel Fuel Filter

During your next diesel fuel filter change, instead of priming the filter with diesel fuel use Sea Foam instead. Start by remove the oil diesel fuel filter. If you have a drop-in filter use a siphon to remove any diesel fuel from the housing before pouring in the Sea Foam. If you have a spin-in filter simply fill the filter with Sea Foam and install it. Sea Foam will clean the diesel fuel injectors. Start the engine and let it idle for two minutes, then shut off the engine. Let the engine sit for 15 minutes to let the Sea Foam work. After 15 minutes drive the vehicle as normal for at least 30 minutes.

Using Sea Foam On The Top-End

To clean carbon deposits from air intake systems, intake valves, and combustion chambers inside the engine, including GDI engines, Sea Foam recommends using Sea Foam Spray Top Engine cleaner and lube (Part # SS-14). Sea Foam Spray is the same great Sea Foam only in aerosol spray instead of liquid form and is a better way to distribute Sea Foam into where it needs to go. Sea Foam Spray is used by inserting the included application hose and patented “HOOK TOOL” into the air intake just in front of the throttle plates in the throttle body.  Then start engine and let it warm up to operating temperature. Increase idle speed to 2,000 RPM and spray the contents of the container into the engine. Shut the engine off and allow it to “Hot Soak” for 15 minutes. After the Hot Soak period restart the engine and road test the vehicle aggressively until the exhaust is clean (road test normally takes 5 to 10 miles of driving). Easy to follow directions are also available right on the Sea Foam Spray container.

Treatments like this may seem complicated, but with a little bit of prep work, you can do it yourself and restore your vehicle’s power and performance. If you have any concerns, stop by your local NAPA Auto Parts Store or NAPA Auto Care Center.

Sea Foam Spray Top Engine cleaner and lube

Check out all the chemical products available on NAPAonline or trust one of our 17,000 NAPA Auto Care locations for routine maintenance and repairs. For more information on how to use Sea Foam Motor Treatment, chat with a knowledgeable expert at your local NAPA Auto Parts store.

Jefferson Bryant View All

A life-long gearhead, Jefferson Bryant spends more time in the shop than anywhere else. His career began in the car audio industry as a shop manager, eventually working his way into a position at Rockford Fosgate as a product designer. In 2003, he began writing tech articles for magazines, and has been working as an automotive journalist ever since. His work has been featured in Car Craft, Hot Rod, Rod & Custom, Truckin’, Mopar Muscle, and many more. Jefferson has also written 4 books and produced countless videos. Jefferson operates Red Dirt Rodz, his personal garage studio, where all of his magazine articles and tech videos are produced.

3 thoughts on “How To Use Sea Foam Motor Treatment: 3 Ways To A Cleaner Fuel System Leave a comment

  1. Thanks for the information I used it in my zero turn motor and it helped a lot and saved me a lot of money

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