Ok, this thread caught my attention in part because I have been reading threads on the OS for a few weeks that seemed to have a lot of conflicting advice and opinions, and in part because on the whole I still felt there was a benefit to be had, and have been in the middle of my own application of SF. IMHO, there is a lot of misguided advice and "not quite correct" application methodologies out there so I'm going to chime in with my opinions and comments, hopefully substantiated by facts where possible. This is now mostly intended for future readers since OP has already completed hers, but maybe it'll serve as a useful future reference too.
Background: Several weeks ago (2 weeks after purchase) I cleaned my throtte body. I noticed at the time that the interior of the intake manifold was covered in the same black varnish crap that the TB was, and assumed it must also permeate much of the engine. Also I'd seen multiple claims of quiter engine operaton post treatment, and after changing out a bad idler pulley I still wasn't satisfied with engine bay noise levels so I wanted to make this my next cheap maintenance step.
So, having now put 7000 km on it since July, my OLM is showing 30%, I've been planning on the SF treatment in the crankcase just prior to changing the oil. It seemed wise to also treat the rest of the systems in conjunction with this, so a week ago I added 1 full can SF to a full tank of gas. From
Seafoam's own website the recommended mixture is 1oz/gal AND "Mixing at less than two-thirds oz. per gallon will impair the effectiveness of Sea Foam." 16oz into 25 gallons is just slightly less than 2/3 oz/gal, so I added another 1/2 can at the half tank mark and continued to run on that gas for the remainder of the week, holding 1/2 can in reserve for brake vaccuum booster line application. Because none of what I had read or saw prior to this had convinced me the vaccuum line application method was better than the spray application through the throttle body plate, I also bought a bottle of the spray to apply that way.
Voymom said:
(3) Do I clean the throttle body before or after the smoke show or does it not matter? I'm trying to get a bit religious about cleaning it with every oil change.
If you're convinced the TB really needs cleaning and/or you intend to use the vacuum line application method then my approach would be to clean it first otherwise if it's only been a short time since TB cleaning and/or you're planning the spray application, then it doesn't seem necessary. Just my opinion but doing full out TB cleaning every oil change seems to be a bit of overkill, as roadie says also later. FYI I'm still sitting on the fence as to whether the "smokeshow" is the real evidence of SF doing what it claims or just a side effect.
Voymom said:
Here is the video I watched. You will see why I ask how long the truck sits turned off. The guy in the video let the truck sit turned off for about 30 minutes after sucking the SF through the break booster line.
Blckshdw said:
When we did mine, and Decembersend's too, we let them sit for about a half hour. We were working on other mods and running our mouths, so that could just be coincidence..
I think the main idea here is to give the SF enough time to dissolve the varnish without being so long that the solvent re-evaporates leaving the varnish deposit behind again. For those that have done their own TB cleaning, you may have noticed that the cleaner evaporates somewhat quickly, especially on a warm day, and the varnish left behind is almost as much a sticky mess as when you started...in my case I waited about 20 minutes before restarting, which seems well in line with Seafoam's guideline of "... a minimum of 10 minutes"
With respect to the video you referenced as your guideline, I am of the
opinion that it is not the optimal method of application for two reasons. First, SF's website seems to recommend revving the engine up a bit during application ("SLOWLY POUR 1/3 to ½ can of Sea Foam Motor Treatment into the vacuum hose, while at the same time revving the engine to about 2000 RPMs"). Second, dipping the vacuum line into the SF results in periodic surges of large-ish volumes of SF being ingested, which has the potential of inconveniently stalling your engine, especially if it's only idling. Again I think the main idea is to give the SF a chance to saturate the crap it's trying to remove, and think the best way to do that is keep the engine running and apply it quickly enough to get a good volume of intake in fairly short order to make it as effective as possible. Also, as shown in the video, dipping the vacuum hose gets SF all over it...you'll find that at 2k rpm, the vacuum strength is quite strong, and direct application from the bottle is possible with no leaks/mess. Hell I did mine at midnight under a streetlight, and didn't spill a drop.
tbuckalew14 said:
You can either plug the tube with your finger to shut it off(although I've only had luck doing this with my jeep not the TB)
FWIW right at the end of applying the can contents, I was able to plug the line with my finger and get the engine to stall...some youtube vids on the subject advocate using the last bit of fluid to give the engine one last large volume dose which can also stall it (prob moreso at idle speeds) so this may be a preferable way to approach getting a good saturation level just prior to the "soak" period.
Voymom said:
Okay, I will wait for others to chime in, I want to be safe and not sorry lol
I do recall having seen some threads on the OS where application of SF was claimed to be the source of some problems, but sorry I don't recall the specifics. A search over there might be prudent. As for my own personal experience, I did hear a couple of engine knocks occur during application when the engine was close to stalling. I suspect the PCM attempted to alter timing to compensate, just prior to me shutting it down for the soak....when I restarted 20 min later I had a CEL on but wasn't terribly concerned immediately because I was almost sure it would clear itself shortly. After 3 subsequent ignition cycles where the light remained on, I used OnStar ODD (on demand diagnostics) to see what the code was (my scan tool won't arrive for a few days yet), BUT just as they put me on hold to run the scan the CEL cleared itself...when I get the scantool, I will look in the history to see what the code(s) were. Otherwise I had no issues. (In fact this CEL may be unrelated, as I know I also have a sticky t-stat which has dropped a P0128 on me about a week ago before clearing itself)
Voymom said:
To late lol it's all done! I noticed that the truck drives so much smoother, shifts smoother, and has a lot more throttle response. IF I created any problems, they haven't popped up yet.
Agreed...I would have to say it runs a bit quieter, slightly smoother and sort of seems to have a little more "snap" at mid-range revs. As for shifting smoother I can't say I noticed that, mine already shifts so smooth it's barely perceptible unless running pretty close to WOT. I also can't quite wrap my head around what the theoretical explanation would be for smoother shifting... can anyone else weigh in with their knowledge/experience on that for me?
Also, Voymom, with respect to the
other thread that we both added comments on, did you experience any measureable performance improvements?
McGMT said:
It is made for this purpose and all there is to it is a small amount of kerosene and propane for combustion....
Just correcting a bit of misinformation here...there is no propane in Seafoam - non-pressurized propane would become gas at above something like -40 deg F IIRC ...check section 2 of the
MSDS for the contents: Pale oil, Naptha, IPA {isopropyl alcohol}
Voymom said:
Like hubby wanted to add seafoam to the gas tank while the truck was running....I told him HELL NO! If you cant put gas in it while the engine is on, your not putting seafoam in it while the engine is on.
jrSS said:
U can fill up while the truck is running. Its not looked upon very nicely but it can be done.
Voymom said:
It is illegal here, and you can get a BIG fine for it.
Just as an FYI, the main reason that fueling up with engine running is frowned upon and illegal, is that there is a greater likelihood of more volatile gasoline vapors reaching the LEL (lower explosive limit) AND being near a potential source of ignition at a gas station. Adding SF to your gas tank in a reasonably well ventilated area has, IMO, near zero chance of reaching it's LEL, partly because of it's lower volatility/higher flashpoint (which is why it can't be used as a cold start agent in gas engines) and because it's also less likely those vapors will be near a source of ignition (notwithstanding dummies who choose to smoke 3" from the filler neck while adding it to the gas tank). I think it's VERY HIGHLY unlikely anything will EVER happen from simply adding Seafoam to your gas tank... but shutting the engine off can't really hurt either.
I even asked him before he put it in the truck if it was safe, and he assured me that all would be okay. Until my SES light came on, and the truck sounded like a trashed out dump truck 
