Piston soak procedure

With the engine at rest, I'd guess two of the pistons are at or near Top Dead Centre, the other two around Bottom Dead Centre: does that matter?

Something else you could try: remove the passenger side wheel, and run a socket (on extension(s)) through to the crankshaft nut, and turn the engine over a a few revolutions, by hand. Wait a few minutes, repeat. With all the spark plugs out it'll be easy to turn over.

I'd be cautious as to how much volume of seafoam you pour into each cylinder though. Determine (say by dropping a slim dowel down each spark plug hole) which pistons are high, which are low. Then pour till it's full only on the high ones, note how much you poured in, and pour the same volume on the low ones, to avoid overflow when you turn the engine.

As far as the need to suck it back out: I watch a video of seafoam (or similar product?) being shot into the cylinders with the head off, and it seeped through within a few minutes, IIRC. Due to the gaps in all the piston rings I guess.

Yeah I think you'd definitely want to change the oil immediately after.

I've never done a soak like that btw, purely winging it, lol.

 

For those who have done the soak, need your comment.

I pour in around 100ml (3.3oz) of Marvel Mystery oil into each piston. After 24 hour, when I check each of the piston are all dried up. Seems like the oil seep down below the piston. Is that normal? How much liquid is right amount to pour in for the soak?

 

I used Mopar Top End Cleaner which is in an aerosol can and is of a much thinner viscosity than oil (almost as thin as water) and none of it leaked past the rings. So it would seem you have serious ring sealing issues.

 

Well, the idea is to get the oil to the rings. So if there is no oil on the pistons, they it's gone through the rings.
Pour more on the pistons and let it soak through. If it just sits on top, then it's not getting through the rings.
I am not sure how long it should take for the oil to get through the rings. It's probably different for each engine.

While you have the head off, I would replace the valve guide seals. I would say there is where most of the oil
is getting sucked through the valve guides. Inexpensive and easy to do while the head is off!

 

Thanks for the comment. I did this on my other car and the oil stayed there over night. That's why I find it weird all sipped pass the rings.

Your comment make sense too! The point of the soak is exactly to allow oil pass through the rings to clean it.

I guess like you said, it's different with different car. I just didn't feel comfortable seeing my piston full of carbon. One of these days, when I skilled enough, I might take up the challenge of doing an overhaul. Till then it's smaller project for amateur me.

BTW, I didn't take off the head. Only took off the sparkplugs and pour the oil from there.

 

Okay, I "assumed" you had the head off! And you know what happens when you assume....

 

I've been prepping for a piston soak and I have a few questions if anyone has experience with this.

1.) The crackshaft pulley bolt. This should turn clockwise, right? How easy is it to access? And it's definitely 19mm, right?

2.) Seafoam seems to be the preferred soaking solution here, but I read (on another forum I'm not allowed to link, but it's my top google result for "best piston soak") that it's kind of ineffective with a more serious buildup problem (my 2010 is at 196k with about 100k of that being city ubering), so they recommend top engine cleaners, including Toyota's (002891TE00) which is pretty cheap. This should work the same or better with no downsides, right?

3.) While I understand the procedure, if someone more aware of the mechanical principles can explain where the carbon deposits and soaking solution will be going when the engine is cranked that would be great. The options to safely remove them as i see it are;
1- change oil immediately after the cleaning and hope the deposits are removed with the oil.
2- drain oil before the soak and leave plug out so soaking solution drains out (would this work?)
3- add bg epr to oil after soak, run for 30 min at 1200rpm, then change oil (would this flush the deposits from the oil better or would this just make it worse by spreading them around?)
4- do number 1- then number 3- (this is what i'm leaning towards).

4.) During the soak/crank cycles, some people suggest re-installing the old plugs finger-tight to 'prevent anything from going down the plug holes and prevent evaporation' while some people seem to accomplish this with clean rags over the pistons. Is this necessary/important? Any reason not to? Is oxygen necessary for the reaction in some way? And several people recommend replacing the old plugs only after driving a few days after the soak. What would this accomplish?

5) The whole idea of cranking the shaft to move the pistons. Some say to soak for a while and then turn, others say to crank it to some ideal position where all 4 are basically level at some midpoint which allows the soak to penetrate to the rings or something? What's the best way to approach this? Planning the job to coincide with either downtime (8 hour/overnight soak before cranking) or while doing other non-engine work on the car (2 hour soak before cranking).

6.) As I understand it, the soak solution should drain during the cranking slower after each cycle until it basically no longer drains because the rings have re-formed a seal with the piston/cylinder. This would be the ideal outcome, so it seems like this might take quite a few cycles on a 196k vehicle that burns the semi-standard 1 qt/1000 miles.

I recently cleaned the EGR cooler for the first time and have used bg epr/moa/44k for the past two oil changes. I'm hoping the piston soak is the solution I'm looking for to get the oil burning under control. I tried an oil catch can, but it made the cabin smell like oil/exhaust. I just want to be able to extend the life of the car for another 100k miles (which might only be another two years at my current rate) and safely limiting the egr/intake/throttlebody cleaning interval to 25k miles (bought new cooler to reduce downtime). I've been using 0w20 pennzoil platinum full synthetic since i got the car at 55k miles and high-mileage version since about 100k. I don't want to use heavier oil, but If there's anything else I'm missing to reduce oil burning, feel free to advise. And I'm attempting this reduction not because I don't want to keep buying oil, it's to keep those egr/intake parts from getting so dirty and clogging which leads to heat problems and the head gasket failure as I understand it. I think my use case of ubering with excessive start/stop is sort of a worst-case scenario for this issue and i just want to avoid it if i can.

 

Do not crank the engine after leaving the soaking agent. It might cause hydrolocking on the engine. You need to extract the liquid out of it using something like turkey baster or some suction tube. Drain as much as possible leaving as little as possible liquid on the piston. Then do a few crank with the plug removed. Put some towel on the open plug hole to catch any liquid that shoot out during the crank. I think you can do this by putting the car in maintenance mode which cranks the engine immediately when you start the car.

Once you manage to remove as much liquid as possible, you can install back everything and start the car. Let the engine run for maybe like 15 minutes. If you want to drive the car around, make sure to exit maintenance mode and drive for maybe 15 minutes. After that you should drain all the "dirty" oil and replace with new fresh oil.

This was how I planned to do mine but the Marvel Mystery oil that I put into the piston all flowed through the piston down into the oil pan. This means my pistons are already not in tight condition which is the reason why the engine is consuming oil in the first place.

Anyway, I am no expert and I also just experimenting with what I learn from various sources. Hope it can give you a bit more insight when you do your "cleaning".