I have a 2011 Prius with 180,000 miles. I’ve noticed I need to add extra oil in between oil changes so it looks like I may have a case of some oil consumption. I don't know the specifics yet (how many quarts per mile). I’ve used the BG hybrid kit (https://www.bgprod.com/services/hybrid/) and maybe it worked a little, but I still find myself needing to add some extra oil. I’ve been reading through these forums and wanted to try a piston soak with Berryman’s B-12 Chemtool and I saw this video () and was surprised by how well this worked. I wanted to follow a similar process with my Prius, but since this is a hybrid that uses the MG to start the engine, I’m concerned about cranking the engine by hand. Is it safe to turn over the engine manually using the crank pulley? I guess I’m wondering if the HV system will care if the engine is rotated from where it last turned off. I would think I’ll just remove the spark plugs, pour in enough B-12 to cover the top of each piston, agitate it a bit by rotating the crank pulley bolt, wait a couple days, agitating occasionally, then suck out the remaining fluid, change the oil, then start it up. Is there anything else I should be concerned with? Is there a way to have the engine crank without trying to start to work the B-12 into the rings?
Yeah work out your consumption rate first. If it's a cup or three between oil changes, maybe fugedaboutit. Hopefully NOT "quarts per mile"... BTW: Considering the 180K miles, have you ever cleaned the EGR components, including intake manifold?
That guy has updated his video this week and found he still has excessive oil consumption at the rate of 1.25 quarts per thousand miles. His new video indicates he's going to try it again. I would be very careful about Hydrolock and oil contamination.
I will figure out the consumption rate, I cleaned all the EGR stuff, manifold replaced the PCV at about 160K.
So how about the question about cranking the engine by hand (using a wrench)? Is that OK? On a "normal" ICE car I wouldn't worry about it, but wasn't sure how the HV system would respond if the crank position changes with the car off.
No problem turning the engine with a wrench.... It's the same and any "normal" engine, because it is. With the car off, the hybrid is off too.
I just topped off the oil. We'll see what happens for the consumption rate. In addition, I thought I could add the B-12 so it covers the whole piston, rotate the crank by hand till it's on a compression stroke and all the valves are closed, then install the spark plug and crank it a few more degrees to give some compression in the cylinders. This would force the B-12 through the rings and give it more penetration. Just a thought. It would also prevent evaporation of the B-12. Doing this would mean I can only soak/compress 2 cylinders at a time but that's OK. I also thought I could drain the oil first, then just pour a bunch of B-12 into the cylinders so I can better monitor what drips out, meaning it's gotten through the rings.
Add fluid to all cylinders, temp install all plugs, rotate? It’s doable, not too hard to turn by hand. I cranked engine by hand thus, checking valve tappet clearance on various Hondas we had.
CR94, the 2 outer cylinders move together, so it would be 2 at a time. But I can also try what Mendel suggested.
Only ONE piston at a time is under compression, I believe. And the two that are at the top, only one of them is on the compression stroke. If you line up all the pistons, fill with whatever you're going to use, then slowly move them up and down a little, then let them soak. You should be the best results.
Only one of those at a time be on the compression stroke. The other is in its exhaust stroke. Same goes for the inner two that move together. If you believe you need each cylinder to go through its compression stroke (slowly, cranking by hand) to push the solvent into the rings, you'd have to rotate the crank pulley two revolutions (as on any other multicylinder 4-stroke engine).
Random timing. It seems like we all came to the conclusion to do a piston soak. Mine spurred from cleaning a gas tank lol. OP did you do your piston soak?
