How to Seafoam an Eighth Gen F150 (1987-1991)
#65
seafoaming
Instead of trying to pour the sea foam into the brake booster line, get a plastic cup and pour 3/4 ounces into it, start truck then place tube into the cup. Vacuum will pull the sea foam into the line
#66
This stuff works!!! Had a friend that had a trailblazer that would not idle, put in the sea foam for 30 minutes, started and drove. Smoked like a freight train, but when I got back to the house it idled smooth
#67
You guys have to be super careful when adding it until the engine dies. I would not recommend that AT ALL. You run the risk of Hydrolock which is NOT worth it.
The way I did mine; I removed the intake tubes, so I had direct visual access to the butterfly valves. I removed the brake booster vacuum line, and held the seafoam up against the line so that you can see the vacuum pulling out the liquid through the Venturi effect.
I let it lightly draw seafoam at idle, just enough to make the engine stumble. Then, I manually open up the throttle to increase RPM's to roughly 2000, and add lots of seafoam. At this point, the engine won't die because the seafoam is burning too quick to kill it. I would add as much seafoam as I could, and if the engine almost died, I revved it more. The truck blew smoke like a train the whole time. I did this with the entire can, and afterwards, my idle was significantly smoother, and the throttle response was fantastic. IMO a much safer way to clean out the engine.
The way I did mine; I removed the intake tubes, so I had direct visual access to the butterfly valves. I removed the brake booster vacuum line, and held the seafoam up against the line so that you can see the vacuum pulling out the liquid through the Venturi effect.
I let it lightly draw seafoam at idle, just enough to make the engine stumble. Then, I manually open up the throttle to increase RPM's to roughly 2000, and add lots of seafoam. At this point, the engine won't die because the seafoam is burning too quick to kill it. I would add as much seafoam as I could, and if the engine almost died, I revved it more. The truck blew smoke like a train the whole time. I did this with the entire can, and afterwards, my idle was significantly smoother, and the throttle response was fantastic. IMO a much safer way to clean out the engine.
#68
Senior Member
I know this is an older post and I love Seafoam. When I was younger an old-school mechanic helped me on my 4.9 and he poured ice water into the motor the same way as with the Seafoam and it was amazing how much carbon that blew out! I still do this today from time to time while also using the Seafoam in the oil and fuel.
#69
Yes,water trickled in the carb throat is an old school way of cleaning the carbon out of the top end. FWIW, it need not be ice water.