My truck in my sig has 195,000 Kms so I thought I would put some Seafoam in the tank to clean up the insides of the engine a bit. On my way home it began to have an awful odour and lost some power. It ran more or less the same as usual but it was definitely down on power.
My question is, what can I expect from my truck with the Seafoam in the tank? How long will the effect last and will it gradually improve? Or, is what I'm experiencing the result of a horribly gummed up engine finally getting cleaned?
I have never put any additives in my truck since dad gave it to me. Just regular oil changes with Castrol GTX so it could be gummed up from the previous owners.

 

When i had my 87 f150 i did the seafoam through the vacuum line. it was interesting to watch, but it didn't really help in all honesty. i noticed a slight power gain, but nothing too big. i ended up just rebuilding the engine a few hundred miles later because of how frustrating the lack of power was. it wasn't one of my best sea foam experiences, but then again i've never tried in the tank. give it a shot, it should help over time. it will help get some gunk out of it. (experience with 1987 f150 lwb 5.0 efi)

 

So, in other words, in spite of the numerous recommendations on here about Seafoam it's the equivalent of a travelling salesman's magic elixir? That's disappointing.

 

I have used it in the past. Its not gonna solve lots of problems, but it does do well at cleaning many parts. I personally haven't added it to my crankcase, but have in the fuel tank and through the brakebooster line.

And yea, it basically falls in the category of Snake oil. But it's abilities to produce results can be objective and is different for everyone who uses it.

 

I had mixed results on my two trucks I used the same procedure mainlined thru the brake booster hose. My ranger 2.3 176k smoked like crazy aND my 97 f350 460 didn't 168k.

 

I add Seafoam to the gas tank, and then fill the tank up.

My back-tank fuel pump runs much quieter than it used to... Previous owner ran the front tank, only.

Over time, the engine idles much better than it used to. I think the injectors are probably spraying better than before.

In a related topic, I own a Lawn Boy mower with the venerable 2-cycle engine that sat unused for a couple of years with fuel in it, and was very hard to start.
I mixed a little Seafoam with some fresh mixed gas in the tank, and after lots of pulling, got it started. Then, I let it sit for about 3 weeks.
At the end of this time, I noticed that the engine would now start on the 4th or 5th pull of the cord. I mowed the grass, and put it away with the same gas mix with Seafoam.
The next time, it started in the middle of the first pull of the cord. It's been running perfectly ever since.

I'm a believer in Seafoam.

 

SeaFoam is good, without a doubt-but if used often, can be quite expensive. I've been using Berryman's for maybe close to 10 years (about 3.25/bottle) in every 4th or 5th fill-up and have NEVER had a fuel-related problem. Now, this is the type of situation that you cannot prove or disprove. There is the possibility that I may have never had those problems anyway, but I'd like to just think that it's cheap insurance!

Roger

 

Thank you everyone for the replies. After driving my truck for about 50 Kms I noticed it was idling smoother and seemed more responsive on take off. Unfortunately my truck has suddenly developed a miss or hesitation so I will have to wait to see what, if any, more improvements I will see with the Seafoam.
BTW, I don't think the miss or hesitation is related. I pulled the codes today and my KOEO test passed without an issue and the KOER test only gave me one code. If you are curious you can look it up on my other thread I started.

Thank you again for the replies.