Pretty common on those engines. It's time for a new motor.
Piston Soak made smoking way worse ?
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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.
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