Ok, I've been lurking here for years, but simply never post.
In a nut shell... I don't know anything about oil other than what I like to piece together from some of the opinions here.
However... I do have two edges when it comes to Seafoam.
1) I've been using it longer than it looks like any of you have.
2) I remember the much more exact directions on the cans from years ago, and yall don't!
Like I said... I don't pretend to know anything about anything.
I'll pretty much hit common things at random & ramble my butt off.
Seafoam either smokes white, or black. That's it.
Seafoam smokes, mostly (IMworthlessO) because of it's contents mostly, and the carbon partly.
40-60% Pale Oil
10-20% Isophthalic Acid
The smoke is mostly the pale oil burning in the combustion chamber & exhaust manifolds.
I have found the amount used has a some influence on how much smoke pours out.
More so than the amount of seafoam used, is the length of time between pouring it in the combustion chamber, shutting off the engine & cranking the engine.
Seafoam mainly cleans the combustion chamber, face & backs of valves.
Seafoam cleans some
of the intake & exhaust track in the heads
. Simply put... You're in la-la land expecting a spray cleaner, or sucking a cleaner is going to do much to the intake track itself (Intake manifold<s> throttlebody area & majority of the head area)
If you want to clean those things, you need to bust out a brush/grinder, some solvent & do it by hand.
Here's a combination of the actual directions for use, with what I have found to be the best way to use it.
Fully warm the engine up before starting.
For the intake, the amount used should grossly depend on displacement. (Can = pint)
My good rule of thumb:
1/4 of a can for 4 cyl / through 2.4L
1/3 of a can 6cyl / through 4L
1/2 a can for 8cyl / 5.7L
My reasoning for this is that it has been my personal experience that if you go using a lot more than you need, a lot of it is simply going to blow right out of the chamber before you get it cut off & it does any good.
This stuff will also cause the engine to diesel if you're using too much... (i.e. you turn the car off, but it keeps running because the combustion chamber temp + compression temp rise is enough to ignite the seafoam)
(Yes... In my few years of recommending it & following it's use on several *huge* Toyota oriented forums, there has been a case of ONE person damaging their engine with it. The engine hydrolocked & spun a rod in the process. It's wasn't a small engine... It's was a 3.4L 5vz-fe V6. The guy accidentally dropped his vacuum line into a full can while a friend held the engine to a cruising speed.)
In light of the above, you want to pour the amount you're going to use in a separate container!
Don't worry about revving the engine up during use.
What you want to do is suck all of it up at one time, or put a funnel on your vacuum line & pour all of it in at once.
If the engine dies from being rich, that's great! If it doesn't, you IMMEDIATELY
want to cut the engine off.
(At worse case - You can stall the engine, but won't hydrolock one using the amounts I recommend - less it is some odd ultra high compression)
When the engine is off you want to wait 5 min
From here we go back to the old directions.
Let the engine idle for 10 min so that the billowing cloud of smoke isn't as bad.
Now you want to go drive until it stops smoking. It is helpful to to hold some gears into your red limit a few times...
If you've got a "smoker" I seriously suggest taking the can of Seafoam with you... If it's bad, you can fill entire city blocks (blocks!?) with smoke, or obscure drivers behind you.
Just incase any cops are anal retentive, you can show him the can & claim ignorance.
When you have finished, [u]you need to repeate the process 2, or 3 times![/u]
On my 3.0L v6, I do it 3 times back to back in one session. There is no point having partly empty cans laying around LoL! (Come on... $5 a can!)
Most people like to put Seafoam in at the end of an oil change, or with new fluid, and do a quick change after a few hundred miles.
This is actually AGAINST what the old directions use to call for. The old directions suggested it's use with fresh oil, over the operating period - without degrading it's service life.
(Trans-tune still says "Fluid can be changed at regular service basis.")
Trans-tune is the opposite ratio of normal Seafoam.
Seafoam swept through about every Toyota based internet forum like wildfire. The stuff works.
It offends some people, but it basically works as good as most people have lucky with a kit of Auto-RX in a short amount of time, for $5 a can. (Not 100% accurate, but you might as well chunk Auto-RX to the bin of stuff that works really well, but is overpriced.)
Another tip... Take a 16oz spray bottle full of water. Put the nozzle into whatever port you have that squirts directly into the post throttle plate manifold. Squirt fast enough so that the engine idle slows down, but isn't sputtering to death.
Make sure it's a mist & not a stream.
It won't "clean" any fuel residue, or oil from the PCV system out, but it will de-carbon any combustion chamber it get's to better than nearly anything else will.
For anyone that doesn't know, water injection is the most awsome thing of all time LoL!
When I rebuilt my engine from a head gasket blowout on the rear bank @ around 96,000 miles. (Ported & polsihed them myself & did a boat-load of misc. work) here's what things looked like.
Don't think anything of the fluids on the pistons. I had a pressure + oil leak on one cylinder. All the fluids you see are anti-freeze & oil that spills into the combustion chamber when you break the seal on our lower intake manifold & heads respectifly.
Anywho... I purposely didn't clean the pistons to see how seafoam would do. I don't have any pictures, but I have examined the front bank twice. After the above Seafoam regimin & after I installed a serious amount of water injection when I turbo'ed the car.
The Seafoam reduced the carbon, the water injection nuked all of it LoL! [ September 14, 2005, 11:50 PM: Message edited by: Toysrme ]