Pretty common on those engines. It's time for a new motor.
Piston Soak made smoking way worse ?
- Thread starter mops
- Start date
If you love the vehicle and if it makes financial sense have a new motor put in it. If not, like others have said...two bottles of Lucas Oil thickener, some Engine Restore, and some 20W-50 to top it off. Trade it in.
I'd say these piston soaks are as detrimental as a power flush of a high mile automatic transmission.
That carbon and goo may be the glue that keeps things sealed for the time being.
The piston soaks are not the cause of the cylinder bore wear.
The piston soaks were done way too late, long after the cylinder bore wear was past the point of no return.
People should actually do a borescope and leakdown test before performing a piston soak, in my opinion.
If you perform the borescope and you see that kind of damage to the cylinder bore, before you start the piston soak process, you know you might as well not even bother.
It's why I get perturbed when I see people trying to troubleshoot issues with their cars and motorcycles completely out of order that makes any logical sense.
But, then again, I don't like wasting my own time on things that won't make much difference in the long run.
Yet I still post on the internet, hoping beyond hope, that someone, somewhere, will take my advice one day.
I never said they were. I said like the goo in an automatic transmission being displaced during a power flush, the same is with the piston soak, that carbon and oil residue maybe what is helping seal the old rings etc. Just saying.
Thanks for feedback.
I would have never expected this type of the damage in the engine, but now I understand. I bought the car cheap to me it makes sense to fix it.
Even If I traded it in I would have to spend heaps more money to get something else. I decided to keep the car and rebuild the engine. Most likely with installing steel liners - but will get the feedback from the local engine builders once i get the block out (likely today). I have done a very successful engine rebuild before (BMW e30/m20b27 turbo still being abused 15 years later).
My biggest concern now is getting the right pistons. I do not like the design of OEM ones. The have undercut ring land over the wrist pin so its very thin and these pistons often fail there. I'll do a thread at audizine about the engine rebuild and link it up once its there.
I would have never expected this type of the damage in the engine, but now I understand. I bought the car cheap to me it makes sense to fix it.
Even If I traded it in I would have to spend heaps more money to get something else. I decided to keep the car and rebuild the engine. Most likely with installing steel liners - but will get the feedback from the local engine builders once i get the block out (likely today). I have done a very successful engine rebuild before (BMW e30/m20b27 turbo still being abused 15 years later).
My biggest concern now is getting the right pistons. I do not like the design of OEM ones. The have undercut ring land over the wrist pin so its very thin and these pistons often fail there. I'll do a thread at audizine about the engine rebuild and link it up once its there.
Given it is a thread about piston soak, and I have performed the said procedure, then disassembled engine, there was unique opportunity to inspect the the results.
All rings were free, but this was not the issue in this particular case. The procedure was performed primarily to dissolve the caked-up building on the oil control rings - a known issue in this engine model.
The picture of the ring itself, the left pats has been cleaned up manually, the right side is as it came out. all the oil rings, on all the pistons were caked up like that.
On the photo of the bottom of the piston (as in where the soak fluid would be most concentrated because of the position of the piston) areas between the rings appear to be cleaner than on the photo of the side of the pistons, but the top of the piston looks similar to the bottom, which makes me think that its the piston rocking motion that keeps these areas clean.
All the pistons looked pretty much the same (other than the ones with the scoring damage)
All rings were free, but this was not the issue in this particular case. The procedure was performed primarily to dissolve the caked-up building on the oil control rings - a known issue in this engine model.
The picture of the ring itself, the left pats has been cleaned up manually, the right side is as it came out. all the oil rings, on all the pistons were caked up like that.
On the photo of the bottom of the piston (as in where the soak fluid would be most concentrated because of the position of the piston) areas between the rings appear to be cleaner than on the photo of the side of the pistons, but the top of the piston looks similar to the bottom, which makes me think that its the piston rocking motion that keeps these areas clean.
All the pistons looked pretty much the same (other than the ones with the scoring damage)
Very interesting! Thanks for taking the time to follow up with the details.
A caked-up oil control ring would explain why the cylinder walls were not receiving lubrication, right?
FWIW -- B12 main component is methylene chloride (if memory serves).
A caked-up oil control ring would explain why the cylinder walls were not receiving lubrication, right?
FWIW -- B12 main component is methylene chloride (if memory serves).
Good for you on doing the work yourself! If you had to drop this car off somewhere and pick it up with a new or rebuilt engine I'd say it wouldn't be worth it.
Will you be assembling it yourself or have the machine shop do that for you?
Let us know what pistons you end up going with. The undercut ring land is pretty common in engines these days. I wouldn't worry about it too much unless you plan on increasing the performance or racing it or something.
Will you be assembling it yourself or have the machine shop do that for you?
Let us know what pistons you end up going with. The undercut ring land is pretty common in engines these days. I wouldn't worry about it too much unless you plan on increasing the performance or racing it or something.
I wouldn't worry too much about the pistons unless it's tuned--though OEM look very expensive. What options are you looking at?
Just did a soak on my 2011 q7 today. Also in NZ, brought some Toulene added 25% atf.
Turned motor over using belt and torx on one of the pulleys.
Ended up just pouring the mix in all cylinders every few hours and turned over by hand.
Left it overnight, today it smoked, I mean for 20min idling still smoking.
Took for a drive lots of smoke, blue smoke on acceleration.
Thought the engine was gone, maybe the rings where sealing because they were clogged, and cleaning made it worse.
After a 20 min drive, no smoke
Fingers crossed, its either out of oil, or its happy again.
Turned motor over using belt and torx on one of the pulleys.
Ended up just pouring the mix in all cylinders every few hours and turned over by hand.
Left it overnight, today it smoked, I mean for 20min idling still smoking.
Took for a drive lots of smoke, blue smoke on acceleration.
Thought the engine was gone, maybe the rings where sealing because they were clogged, and cleaning made it worse.
After a 20 min drive, no smoke
Fingers crossed, its either out of oil, or its happy again.
This is why a piston soak should always be followed by some kind of lube dosing. Even if it's diesel fuel, at least there's SOME lubricity vs a harsh solvent.
For a post-soak lube, I like the Lucas Upper Cylinder stuff.
That engine is toast. Heavier oil will stop it. 20W50 mixed in with some 10W40. Adjust as needed
4WD
$50 site donor 2025
OP has been gone a while …
We don't know if most of this damage was done before he bought it, BUT, I am one not into piston soaked as the carbon and soot can get packed into the oil ring and lands. Not always, but still a risk. I would first use a high ester based oil or Valvoline Restore and Protect and let this carbon slowly and safely flush out. Choices...... Redline Performance, Motul 300 with high ester. Valvoline Restore/Cummins diesel oil. HPL oil and say 2 qts HPL Engine Cleaner. with your regular oil for 4 oil changes. Many piston soaks have made it through with no issues, I understand that too. I would just take the ease route of oil choice known to clean bad carbon deposits in the ring land area. Redline Performance Euro 5w-30 cleared my massive fuel dilution problems, with "what I feel " where jammed top and 2nd rings. I also in the fall/winter/ spring time ran 5) oil dumps every 3,000 miles to lake sure the ring lands were clean.
Last edited:
13' CRV was on a constant oil burn around 300K. Did a piston soak first. Helped a little bit. Then tried 2 rounds of BG PN 109. That cleared it up 100%. Cats finally died at 614K, so I think I caught it in time before they got ruined. Still do the 109 every now and again. Once my stash is used up, I'm switchin over to 5W30 Valvoline Restore and Protect, if the K-24 is still alive. Unfortunately, I had stashed a lot of oil before learning about Valvoline Restore and Protect on this forum. But it's quality oil, full synthetic, Pennzoil / Mobil 1 / Valvoline / Quaker State. 3k oil and filter changes.
Is everyone removing the exhaust from the manifold when first running the engine after that soak?
Or is it no care about the Cat's or sensors?
Or is it no care about the Cat's or sensors?
In my 13' piston soak, ummmm,,,,,,no I did not. Actually, never crossed my mind. My bad big time. But, you are 100% correct. All that smoke plugs up the CATS and fouls the sensors. I guess I got lucky, no damage was done. Soak was done at 300K,,,,,,,,both CATS died at 614K. Replaced with OEM Honda CATS and OEM sensors while it was apart. I did use Techron & Cataclean on a regular basis after the soak. Usually every 6k. Maybe that helped ???
Have you done a compression test after the piston soak?
I believe worn bearings can allow too much oil to be splashed up onto the cylinder walls. More than the oil control rings can handle.
I would think solvents like acetone or lacquer thinner or benzine or even gasoline would work in a piston soak.
How many miles on this engine?
