You're not supposed to put it through just any vacuum line. It has to be a line that most evenly distributes between all cylinders....in most cases, it's the brake booster line.

A note of caution since chances are this might freak you out when you pull the brake booster line, your engine will rev higher. This is normal. Don't pour the Seafoam in either, let the vacuum of the engine "slurp" it in. If the engine starts to die, you're going too fast so slow it down. As mentioned, 1/3 can will be more than enough. You can use a whole can....but this is ill advised. And no, it will not hydro lock the engine, even if you use a whole can. There will be a crap ton of smoke. This is all the carbon build up in your engine being blown out.

Also, you don't need a helper to keep the engine running. At no point should the engine die. If it does, you went too fast. Let it sit for about 10 minutes before you start it back up. This lets it heat soak in the engine and does a much better job. I've used Seafoam a dozen times in my own vehicle and I use it at the shop. I'll post you a vid of what happens when you use a whole can.

 

But does the stuff actually work?

 

Yeah, it works. I've been using it for years, (make that decades), in cars, snowmobiles, boat motors, lawn mowers, weed whackers, chain-saws, motorcycles.... It's also great for 'pickling' an engine that's being stored during the off-season

Like said above, add it very slowly in thru the brake booster vac line. Do not use the vac line up near the MAF, MAP or thru the vac line for the HVAC.

On a warm engine, 'meter' it in at a slow, controlled speed. You'll have some smoke as you put the stuff in. About 6oz would be good for starters. Then shut the engine off, revonnect the brake boost line & wait 20 minutes or so before restarting the engine, and idle the car out of your neighborhood.

Once you are clear of the neighbors, hit it! The smoke will be epic!

It'll only take a few moments for the exhaust to clear, and the cat will be hot enough to burn off all the residue. Add the rest of the can to your gas tank and you are done.

Now, just add one half can to a full fuel tank, (6oz to 15 gal fuel), every 3000 - 4000 miles & you are good.

Adding it to your engine oil is a way of 'pickling' for the off season, and it will break down sludge, carbon & stuff like that. Be ready to change your oil/filter within a couple operating hours if you do that trick (filter may not be able to hold all the crap), and do a oil/filter change AGAIN after another few hours (200 miles), of operation. That oil filter will be working overtime to grab all the crud.

Naphtha is the active ingredient, so wash your hands good if you get em wet with the stuff, and keep it outta your eyes.

 

Only part i disagree with in this post is not having a helper. Your supposed to keep the engine reved 2k RPM, its hard to do yourself. Sea foams says this btw. Also Sea foam will not idle the engine up anywhere near 2k RPM on its own. It actually idles it lowers and lower as you add it through the hose, hint the helper. Of course when you stop adding it, it will idle it slightly higher. More then likely you wont even notice.

If you have a cup you can set it some where on the intake and 1 hand the throttle and the other hold the hose a little above the cup(it will suck it out).

P.S: Does not matter how slow you add it, the engine will always try to die at some point. If it does no biggy, start it back.

 

I would never add it to my engine and shut it off for 20 minutes. To each his own, but sea foam does not say do this either.

 

Pulling a vacum hose(brake booster) will cause high rpms. I never had help while pouring seafoam in

 

I'm going to give this a try then. Confusion remains. Put it in and let it sit....running or off? Drive it afterwards?

 

I've never seen a Seafoam bottle that says to keep it revved at 2k and I sell this stuff on a daily basis. And yes it does matter how slow/quickly you add it. You're not supposed to pour it in. The vacuum from the engine is supposed to slurp it in. The engine will try to die, but you're supposed to back off if it starts too. Will it hurt any thing if he does let it die? No, but it's a waste of fuel to let it die and then start it back up again.

This is straight from SeaFoams website and correct me if I'm wrong, but it is pretty much what I said in my first post.

It is important to make sure the engine is at operating temperature. Then find a vacuum line that feeds all cylinders, usually the PCV hose or the vacuum brake booster line may feed all cylinders. If you are in doubt as to which vacuum line to use, YOU MUST check with a certified auto technician. If a technician is not available or if your engine doesn't have any vacuum lines, then use the Sea Foam Spray method described in another section of this web site.

After the correct vacuum line has been located, start engine and disconnect vacuum line. With engine running at idle and at operating temperature slowly pour Sea Foam into vacuum line. It is important to control the rate at which Sea Foam goes into the vacuum line. The engine will labor while applying Sea Foam. Pour enough Sea Foam into the vacuum line to make the engine labor at idle, but not enough to stall engine.

After 1/3 to ½ can of Sea Foam has been induced into the engine, shut engine off and let sit (hot soak) for about 5- 10 minutes and reconnect vacuum line. After the 5-10 minute hot soak period, restart engine in a well ventilated area as exhaust may be extreme for a short time. Road test the vehicle immediately after start up, driving aggressively until exhaust looks normal. This usually takes up to 5 miles. It is always better and safer to road test car to clean the gum, varnish and combustion deposits out of the engine.

By doing this you have done an intense deposit cleaning procedure to your engine. This operation is recommended once a year or every 15,000 miles.

Not trying to be an ***, but I have to explain this to pretty much every customer that buys it. To make the instructions short, start engine, pull line off brake booster, let vacuum slurp in about 1/3 of a can, shut engine off for 10 minutes, then go back out and drive it somewhere where you can hammer it to the floor.

 

Sorry for the quality, but this is what happens when you put a whole bottle of Sea Foam in your fellow employees car, without him knowing. Haha

 

I'm pretty sure i never said anything about just dumping it in. Also it was a Sea Foam REP that told me it works best if you keep the engine reved to 2k. I'm not going into details on why he said all this beacues I'm to damn sleepy to keep typing, but it made complete sense.

Anyhow this is how i do it, and works for me. Every one as their on method on sea foam.