Earlier this year I was struggling with a bad oil consumption problem on our Toyota minivan. It was burning a quart of oil with each fillup very consistently. No leaks or seeps anywhere, and sometimes oily stuff would come out of the tailpipe. From what I had read it is common for the late 2000s to mid 2010s Toyota engines to have stuck rings. I experimented with a couple different flushes (stuff you add to the crankcase, run for a while, and then drain out) but it never did anything.
The guys at Bobistheoilguy.com turned me on to the idea of a piston soak procedure with
Berryman B12 Chemtool. After a good soak over a couple of days the van took a solid 3 minutes of cranking to restart, belched a tremendous amount of black-blue smoke and permanently stained the concrete under the tailpipe. After that it completely stopped consuming oil and ran better than ever. I had such good success with it I thought it would be interesting to try it on the 4Runner as well.
Pull plugs, pour 2.5 oz into each cylinder, and crank it over slowly by hand to help the solvents work in and splash the backs of the valves too. Wait a few hours, and do it again a couple times. This used up two cans (less than $10). Drain the oil and filled with fresh.
After I started it the engine cranked right up and only gave a couple small puffs of whitish smoke out the tailpipe. Cardboard underneath caught a small sprinkle of black carbon soot.
Took it on a short drive then drained the oil and filled with fresh again. Drove it a couple of days and then did a proper oil change with filter. Ran perfectly without any perceptible difference.
I then tried another compression check and found that the compression went up a bit in all cylinders: 180, 193, 186, 190 psi. Was interesting that before starting it up after the soak I checked if there was residual solvent above the piston -- only piston 1 retained any (which I pulled out with a dropper) and that's also the cylinder with the lowest compression of the four.
It was interesting to see the difference between an engine with a bad carbonization problem and one without. Regardless I think it was a marginally helpful procedure.
PSA -- Do NOT run the engine without first draining out the sump with the solvent in it. After that nasty stuff goes into the oil it is NOT a lubricant anymore. You can find any number of people on YT and forums who report rod knocks after attempting to run the engine with solvent in the crankcase. Don't do it!
Thanks for reading! :whoo:
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