Seafoamed no smoke.

[3000GTCSULB]

Put 1 can in the gas can.
Half in the crank.
Half in the brake booster.

Let the car idle for 10 mins and in that time I go no smoke. Is the smoke the result of seafoam in the crank or in the vacuum lines?

I took the car out for a 10 min drive then I changed the oil.

[EthanS]

I assume by brake booster you mean you took the line off for the brake booster on the plenum then poured it into the port on the plenum side? And you poured it into the plenum with the car running correct? If you did it with the car off it probably all just leaked down the open intake valves. Which would probably still smoke for a short bit... unless you let it sit for awhile then it probably would have just leaked down past your piston rings too...

Always want to change the spark plugs after you seafoam the intake (so I have heard).

Smoke comes from adding it to the intake plenum (via vacuum line port)

[Hym3n]

Always change the oil after a seafoam treatment. Spark plugs... meh, if they're coppers go for it.

[RL7]

You want to add it to the manifold/brake booster with the engine running and shut it off/stall it out as soon as the seafoam is added. Too much seafoam too quickly will probably stall the car, not a big deal, not enough fluid to "hydrolock" the engine. Then let it sit for a while. I let it sit overnight. The seafoam sitting in the upper end, hopefully dissolving deposits, is what causes the smoke. Start the car and let it idle and then drive/rev it a little, getting the RPMs up. There should be smoke. Drive until there is no smoke. Change the oil. Fixed a stuck ring for me. Seafoam can work wonders.

[x2xtreme360]

You have to stall the engine right after you put the seafoam in the vac line.