where does this stuff go? Straight into the gas tank?
For a complete seafoam treatment you would do the following:
1) Have new oil, plugs and oil filter.
2) Take 1 full can of seafoam and divide it into 3rds.
3) Pour 1/3 of a can of seafoam into your oil. Then start your engine. Let your engine idle for about 20 minutes.
Do not rev your engine or raise your RPM in any way.
4) Drain old oil, replace oil filter and put in new oil.
5) Locate a vacuum source routing into the intake on your engine. For cars its typically a brake booster line. For my motorcycle I dumped it right into the intakes. Once you've found out where to put it, start the engine and have a friend work the throttle.
6) As the engine is idling begin to pour another 1/3 of a can of seafoam in. The engine will want to sputter and die on you, instruct your friend to raise the RPM of the engine in order to keep it alive as your pour the rest of the seafoam in.
7) At this point you will notice smoke coming from your exhaust, don't worry it's supposed to do that.
8) Once you are done pouring seafoam into the intake shut the engine down and let the engine sit for about 15-20 minutes.
9) After that time start the engine. There will be a lot of smoke coming out of the exhaust, and when I mean a lot of smoke...i mean a LOT of smoke. Don't panic. Just rev the engine moderately until it stops smoking. Some people like to take the vehicle out for a ride to blow it out to put a load on the engine. Thats up to you but I doubt anyone driving behind you will be able to see the road so keep that in mind.
10) Once the exhaust has stopped smoking shut off the engine and pour the final 1/3 of the can directly into a full tank of gas. Drive normally until you have depleted the tank.
Voila your done.
Now a warning about Seafoam. It is a cleaner, it will clean and lossen all that crap that is in your engine and your fuel system. It does what it claims to do and it does it well. However, IF your engine is extremely neglected you "may" encounter a problem but thats your fault, not Seafoam.
For instance, if you have a high mileage engine that has so much carbon crap built up that its literally holding the engine together from leaking oil from a gasket that blew about 20k miles ago. Once you remove that buildup, you will expose the leak. Seafoam did
not cause the leak, the leak was already there. Seafoam just exposed it.
If your fuel delivery system is so gummed up with large deposits of crap. Seafoam will dislodge this and that crap may very well cause a blockage. Again, this was a problem you already had. Not Seafoams fault.
If you run Seafoam into a fuel injected engine that has suffered years of neglect and tons of carbon buildup, keep in mind that your computer will have made some adjustments to fuel trims etc to compensate for your neglect. Seafoam will wipe away all that crap but your ECU might throw a fit because it no longer understands how to operate a properly running engine. Again, your fault. Not Seafoam. Reset your ECU and move on.
I could go on and on but the at the end of the day it's this. If you run Seafoam regularly, like every 3rd or 4th oil change its fine. But if you have neglected your engine, used cheap gas etc etc. Then you already have problems. Using Seafoam will uncover and shine a spotlight on your neglect.
This is why you get so many "mixed reviews" about it. No one, ever admits to neglecting their vehicle.