How To: Cleaning Engine, Fuel System & Crankcase with Seafoam™

Submitted By: Dingo


This general cleaning procedure is a great way to keep your engine running great. Steps 1-2 will clean fuel injectors and carburetor jets, clean carbon as you drive, lubricate the upper cylinders, de-ice and remove any moisture in the system, stabilize the fuel and act as a full diesel-fuel conditioner and anti-gel agent. Steps 3-4 will free sticky lifters and rings; increase RPM's, vacuum and compression; clean any dirty parts; remove moisture; and clean the PCV valve system. The remaining steps (5-11) will clean any carbon buildup, clean the intake valves and pistons, create a smoother idle, clean the catalytic converter odors, cure hesitations and pings, and restore power and pickup. Overall, this is a great maintenance that should be performed on a fairly regular basis.

Required Material


  1. Pour entire can of Seafoam in gas tank.

  2. Fill gas tank the rest of the way with gas.

  3. Pour one-half of the second can of Seafoam into the crankcase.

  4. Change oil within 100 miles.

  5. With warm engine running, SLOWLY poor 1/2 pint through carburator, throttle body or direct manifold vacuum line line that will feed ALL CYLINDERS. Possible sources are P.C.V. valve or brake booster line. Reference your Maintenance Manual for further information.

  6. Turn the ignition off. Keep the vehicle turned off and then restart engine after 5 minutes. Be sure exhaust is well ventilated. Fumes will be extreme for a short period of time.

  7. Open hood and locate the vaccuum hose going to the Vaccuum Assist Booster (aka Brake Booster). Reference your Maintenance Manual for the correct location of this hose.

  8. While the engine is running, remove hose from booster.

  9. SLOWLY tilt the can toward end of hose, allowing engine to SLOWLY suck in nearly the rest of the can. If you pour it too fast, you'll hydrolock the engine. You DON'T want that. The best approach is to hold the can with one hand and hose with the other.

  10. Turn off the engine. There should be about an ounce of Seafoam left in the can. Pour the remainder of the can down the hose.

  11. Replace the hose and close the hood. Wait 5-10 minutes.

  12. Start the vehicle. Note that it may be difficult to start. Once running, 'drive it like you stole it' until the white smoke stops. The average vehicle will smoke for 10-15 minutes.

  13. Enjoy your clean engine!

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