I am doing a bunch of work on a neglected 98 4runner w/ 165k on it. I just starting reading about seafoam, unfortunately after I changed my oil. I am planning on changing the spark plugs and wires and just want to make sure I understand how to use this stuff correctly.

If I don't put it in with the engine oil then I don't have to change my oil again, correct?

If I put it in the gas tank and the PCV hose then I should do it before I change my spark plugs?

Can I run it through the oil before I change it later (scheduled change) and not have it effect my spark plugs?

I know I have read some people say it never effects the plugs but just trying to be extra careful and not waste any more time and $$.

Thank you, this forum has been amazing for help and knowledge

 

Whenever I've added SeaFoam to the oil I always did it when I did an oil change. It thins out the oil pretty good and I never took the chance of driving it like that. It makes the oil run like water and my thought is that it wouldn't do anything to protect the metal if it's thinned out that much.

I don't know about the plugs. I've never had it affect mine on anything I've used it on.

 

I use about half the can in the gas tank every few months, and occasionally through the vacuum. It shouldn't effect the plugs, if anything it could clean them. If you use it in your oil then I would do it about 25 to 50 miles before you change it, but I've heard if you leave it in there too long it could cause damage.

 

I'd put it in the tank, and order the spray to do the throttle body and intake areas.

 

I usually do half in the tank, 1/4 to 1/3 into a vacuum line on the intake, and the remainder in the oil right before an oil change.

 

I have recently had very good luck with the Redline fuel system cleaner. SG-1 or SI-1 or whatever. Made my truck much smoother and responsive. Put it in the tank when I filled up and it was great. Just a suggestion...