My friend and I have been having a debate over seafoaming the motors.
I did it to my celica before my rebuild, some in the crankcase, some in the intake. none in the fuel.
I did notice an increase in performace - very small, possibly just placebo effect
Thing is, when i tore my motor apart a few months later, i found a number of oil seals leaking, my o2 sensor was shot (20L/100km or 10mpg) and the exhaust was starting to smoke more than normal. It only has 65k km, however its an '89
I only ran the seafoam in the crankcase for 50 km. I did a 50/50 split of seafoam through one of the vacumme lines on my TB, and the crank case.
When i tore into the motor, i found lots of carbon deposits on the top of the pistons, and all the valves. It had appeared as though Seafoam didnt even nick the surface.
So i tried pure seafoam on a rag, and scrubbed hard - all that was really removed was trace amount which appeared as a black smudge on the rag.
I let some valves sit over night in seafoam - no effect. Still had to scrape the stuff off.
So, there is no way im going to risk seafoaming my motor now thats its rebuilt with brand new seals.
My friend on the other hand, who has a 3rd gen, and is also rebuilding, has been squirting pure seafoam into his motor for a while now lol. We're hoping nothing bad has happened to it. kinda late now.
I dont know for sure if the seafoam caused the leaks, or if it just made them worse. But im not going to risk it.
There were also some black oily deposits (not carbon) on the Toyota Variable Induction System Butterfly Valves, which control airflow to the motor after the TB, right before the intake valves.
Sea foam failed to clean these off also.
My 2 cents.
Last edited by Corey Darling; 04-01-08 at 03:28 PM.