Hi to all, I grew up in the Motor City and I'm cursed with a little knowledge of the internal combustion engine. I put thirty years in at Ford and I continue to repair, modify and play with vehicles with gas and diesel engines. My latest adventure is with a 2005 Subaru 2.5L non-turbo boxer. It consumes oil at a rate of about 1 quart every 300 miles on the expressway. I suspect piston oil rings that are stuck as a result of carbon/sludge and I am considering a serious engine flush. My first question is: Am I at he right place in the forum to start such a discussion? I would like to post my initial findings and my proposed method of defeating the assumed stuck piston rings in an attempt to get input. Many of my past searches have brought me to this site and here i am again, so thanks for being here.
Newbie intro and guidance request
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BG109
Then short changes with a 10w40 HM oil like MaxLife
Replace the PCV valve
Then short changes with a 10w40 HM oil like MaxLife
Replace the PCV valve
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Piston soak on this engine is a waste of time, its a horizontal engine and only the lower part of the piston will get any of the solvent and with the high consumption rate you are experiencing it will pass right by the piston.
The good news is you can pop the pistons on this engine without splitting the cases the bad news is you have to remove the engine.
What you could try is replace the PCV as posted in this thread and do a idle only flush for 15 min with Berrymans Chemtool, change the oil and filter and fill with a 5w40 HDDO oil and a pint of Kreen.
Run it for 1K then repeat a few times, it may help. You may have broken rings and in that case its not going to help but its worth a try.
The good news is you can pop the pistons on this engine without splitting the cases the bad news is you have to remove the engine.
What you could try is replace the PCV as posted in this thread and do a idle only flush for 15 min with Berrymans Chemtool, change the oil and filter and fill with a 5w40 HDDO oil and a pint of Kreen.
Run it for 1K then repeat a few times, it may help. You may have broken rings and in that case its not going to help but its worth a try.
I’m considering doing a fast flush on a 2005 Subaru 2.5L non-turbo boxer engine. The oil consumption has gotten pretty bad and I have reason to believe the oil rings could be sludged and or the piston oil ring return holes are plugged. I’ve read of others that have had this problem and saw pics of carbon-ed oil rings and pistons. Apparently the boxer lends itself to this type of problem when you are not super critical about frequent oil changes and synthetic oil. The owner has been doing his own oil changes at an interval of 4-5k miles with low cost dino-oil. This, along with the customer working at a local university and only driving 3 miles each way to work lends me to think that stuck oil rings are a strong possibility.
I’m trying to devise a plan and my first step was to find a solution that would completely dissolve carbon from a piston without having to scrape, scour or rub to accomplish this. I went to the lawn mower shop and found a nice crusty specimen piston, probably out of a V-twin zero turn. I then gathered up a bunch of snake oils: Fuel oil, ATF, MMO, Motor Medic, Autozone lifter treatment, Berry carb cleaner dip, brake cleaner, MEK, Acetone and Simple Green. I tried soaking piston in all solutions for 4-5 hour periods in non-diluted compositions on a portion of the piston. The only one that had any noticeable effect at all was Simple Green. I even tried combinations like Diesel and carb cleaner, MMO and Acetone etc. After a 12 our soak in Simple Green 98% of the carbon was completely gone and the portion that was dipped is like brand new. There were a couple of little spots of carbon that were still present. This concerned me as in my mind this extra tough carbon represents the oil return holes under the oil ring. I then soaked it for 12 more hours and 100% of the carbon was dissolved. I have repeated this experiment with Simple Green and I’ve had the same results.
Assuming the engine runs good, has good compression and a borescope shows no scored walls I would like to try soaking the oil rings with SG. The question becomes how to accomplish this and how to clean up afterward. My thought is to drain the oil, replace the oil filter and then over fill the crankcase with simple green and allow a 24 hour soak. I suspect the SG would find its way into the combustion chamber so I plan to drop the exhaust manifold to avoid getting stuff in the cats. After the 24hr soak I would flush a second time with SG in an attempt to flush more solids out. Next I am thinking about flushing the crankcase with a mixture of 90% diesel 8% motor oil and 2% 911 (water dispersal) to flush out more solids and the Simple Green that may still be lingering. This followed with a couple of fast oil changes.
Prior to the attempting the fast flush I started with a slow flush. We added MMO and 200 miles later I added a half can of Kreen (Nano Labs internal engine cleaner) and the customer is currently driving the vehicle. This will probably go on for 200 more miles before I drain it out and start the fast flush.
So now I’ll put my bullet proof vest on and ask for your comments and what you think my pitfalls will be . I’ve probably missed some obvious things, there may be some hidden dangers and some will question my sanity but that’s why I’m posting. Thanks
I’m trying to devise a plan and my first step was to find a solution that would completely dissolve carbon from a piston without having to scrape, scour or rub to accomplish this. I went to the lawn mower shop and found a nice crusty specimen piston, probably out of a V-twin zero turn. I then gathered up a bunch of snake oils: Fuel oil, ATF, MMO, Motor Medic, Autozone lifter treatment, Berry carb cleaner dip, brake cleaner, MEK, Acetone and Simple Green. I tried soaking piston in all solutions for 4-5 hour periods in non-diluted compositions on a portion of the piston. The only one that had any noticeable effect at all was Simple Green. I even tried combinations like Diesel and carb cleaner, MMO and Acetone etc. After a 12 our soak in Simple Green 98% of the carbon was completely gone and the portion that was dipped is like brand new. There were a couple of little spots of carbon that were still present. This concerned me as in my mind this extra tough carbon represents the oil return holes under the oil ring. I then soaked it for 12 more hours and 100% of the carbon was dissolved. I have repeated this experiment with Simple Green and I’ve had the same results.
Assuming the engine runs good, has good compression and a borescope shows no scored walls I would like to try soaking the oil rings with SG. The question becomes how to accomplish this and how to clean up afterward. My thought is to drain the oil, replace the oil filter and then over fill the crankcase with simple green and allow a 24 hour soak. I suspect the SG would find its way into the combustion chamber so I plan to drop the exhaust manifold to avoid getting stuff in the cats. After the 24hr soak I would flush a second time with SG in an attempt to flush more solids out. Next I am thinking about flushing the crankcase with a mixture of 90% diesel 8% motor oil and 2% 911 (water dispersal) to flush out more solids and the Simple Green that may still be lingering. This followed with a couple of fast oil changes.
Prior to the attempting the fast flush I started with a slow flush. We added MMO and 200 miles later I added a half can of Kreen (Nano Labs internal engine cleaner) and the customer is currently driving the vehicle. This will probably go on for 200 more miles before I drain it out and start the fast flush.
So now I’ll put my bullet proof vest on and ask for your comments and what you think my pitfalls will be . I’ve probably missed some obvious things, there may be some hidden dangers and some will question my sanity but that’s why I’m posting. Thanks
Thanks I did read the procedure for popping the pistons and this is not beyond my abilities however it may not be worth the investment considering the cost verse worth of vehicle. I believe to be successful a solvent that is known to cut the carbon has to be used and the entire piston needs to be submerged. I am not confident in combustion chamber flush or additives/flush that you can add to the oil. Also thanks to the heads up on the PCV valve. That would be sweet if that was all i needed.
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At this point, why not fill the engine with SG, combustion chambers and all, then drain and flush and flush and... Prime the oil gallery with oil before restarting. But remember, SG is not all that powerful and will not attack or dissolve thick hard carbon deposits. I'd guess it will not free stuck rings.
Or you could try Chem Dip and/or sister products such as liquid paint gun cleaner. These products will dissolve hard carbon. https://www.youtube.com/watch?v=MI2eLGlkE8Y
Or you could try Chem Dip and/or sister products such as liquid paint gun cleaner. These products will dissolve hard carbon. https://www.youtube.com/watch?v=MI2eLGlkE8Y
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Any compression test or leakdown test done ?
I would try spraying some sort of cleaner in through the throttle body like Amsoil Power Foam or CRC D.I./Intake/Turbo cleaner. This will get into the ring packs and if it's going to un-stick it will happen with one of these products in your case.
Be sure to change the oil after application.
The only reason I'm recommending this is because a piston soak is not going to be effective in your case due to the engine design.
Be sure to change the oil after application.
The only reason I'm recommending this is because a piston soak is not going to be effective in your case due to the engine design.
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Op said, "...and then over fill the crankcase with simple green and allow a 24 hour soak. I suspect the SG would find its way into the combustion chamber...".
You mean completely fill the crankcase so the cylinders are filled / submerged from behind? If so I think turning the crank 15º back and forth would contribute to working any solvent around the rings. Have the plugs loosened so the air can get out (displaced by the solvent) and so that "hydrolocking" doesn't interfere with your goosing.
The underside of my oil fill cap was chunky with black oil bits. I set it into a small dish of Purple Power (another "modern cleaner", likely the same as Simple Green). It worked well but my faith in such a product eating encrusted diamonds from teeny-weeny oil return holes drilled into piston skirts isn't strong.
If I was doing anything like what you're suggesting I would consider following the SG/PP step with something else. It's been my experience that "multiple wave attacks" are better for hard dirt / stains. There's a "WTH" factor given you're already doing it.
My engine has an oil return pathway which includes a "breather box" (or drip catch box) behind the intake manifold, a short tube to the side of the block and an internal passage conveying said caught oil down to the oil pan to a point below the oil's level.
This passage can become blocked with sludge. I've seen pictures.
I had the idea to drain the oil and fill the crankcase up to a point above the short tube in such engines.
Mine is showing no signs of being clogged because the vehicle has seen good maintenance. When (and if) the PCV system's catch box needs replacement I'm going to use a bottle brush on the block side hole and reach down as far as aI can. MAYBE I'll consider flooding the crankcase with deadly solvents.
Maybe you can erect a big rig which can hold that Subaru sideways so you can do piston head soaks. Drain the oil, gas tank, ashtrays and coolant reservoir if the cap isn't airtight.
You mean completely fill the crankcase so the cylinders are filled / submerged from behind? If so I think turning the crank 15º back and forth would contribute to working any solvent around the rings. Have the plugs loosened so the air can get out (displaced by the solvent) and so that "hydrolocking" doesn't interfere with your goosing.
The underside of my oil fill cap was chunky with black oil bits. I set it into a small dish of Purple Power (another "modern cleaner", likely the same as Simple Green). It worked well but my faith in such a product eating encrusted diamonds from teeny-weeny oil return holes drilled into piston skirts isn't strong.
If I was doing anything like what you're suggesting I would consider following the SG/PP step with something else. It's been my experience that "multiple wave attacks" are better for hard dirt / stains. There's a "WTH" factor given you're already doing it.
My engine has an oil return pathway which includes a "breather box" (or drip catch box) behind the intake manifold, a short tube to the side of the block and an internal passage conveying said caught oil down to the oil pan to a point below the oil's level.
This passage can become blocked with sludge. I've seen pictures.
I had the idea to drain the oil and fill the crankcase up to a point above the short tube in such engines.
Mine is showing no signs of being clogged because the vehicle has seen good maintenance. When (and if) the PCV system's catch box needs replacement I'm going to use a bottle brush on the block side hole and reach down as far as aI can. MAYBE I'll consider flooding the crankcase with deadly solvents.
Maybe you can erect a big rig which can hold that Subaru sideways so you can do piston head soaks. Drain the oil, gas tank, ashtrays and coolant reservoir if the cap isn't airtight.
The vehicle belongs to my son in-law who lives in Missouri, I plan to visit over Xmas vacation. At that time I'll attempt the leak down test, replace the PCV and take one of the "through the throttle body" cleaners. Thanks for product recommendations and methodology to all.
Don't use non-petroleum products in the engine, regardless of such advice. If you have the time, take out the plugs and fill the cylinders with diesel. Let it set for a couple of days, then push out the diesel, button it up and drive it, see how it goes. To do this, you want to remove the exhaust pipes to avoid damage to the cats.
Something I did long ago was to drain the oil and fill with 3 qts 40w oil and 2 qts of diesel. Started and let it idle for 20 minutes or so. Drained and checked the oil. It was black! Changed the filter then did it twice more. Finally filled it with the normal oil of the day and gave it back to my dad. Told him the change the efing oil once in a while. It seemed no worse for the wear.
Something I did long ago was to drain the oil and fill with 3 qts 40w oil and 2 qts of diesel. Started and let it idle for 20 minutes or so. Drained and checked the oil. It was black! Changed the filter then did it twice more. Finally filled it with the normal oil of the day and gave it back to my dad. Told him the change the efing oil once in a while. It seemed no worse for the wear.
Yes Kira, My proposal was to overfill the engine beyond piston height with Simple Green, pull plugs to prevent hydro lock, drop the exhaust to monitor what is coming by the pistons and occasionally roll the engine over by hand. Oldmoparguy, after Simple Green flush, my plan was to flush crankcase with mixture of diesel, oil and an alcohol (Drygas/911) using the same method as the Simple Green flush. Of course I would follow up with some quick oil changes as well. I hope you can expound on why you are opposed to non petroleum products being used. I know this is very out of the ordinary and I am unsure myself of the results/pitfalls. I would like to hear your thoughts and experiences. I have not yet committed to any method. Thanks again to all.
On the contrary, I have run numerous test on carbon-ed pistons. After 24 hrs in SG the carbon is 98% gone without wiping or rubbing. After 48 hrs even the toughest carbon is completely gone. the active ingredient in Simple Green is Tetrapotassium pyrophosphate crystal, .05% Interestingly, the soap you get at the paint store for washing walls prepainting, TSP, is the same stuff, Tetrapotassium pyrophosphate crystal but at a 5% concentration. I have added the TSP soap to the Simple Green and now running a test with this solution to see if required soak time is decreased.
If you were to fill it with SG and allow it to soak overnight which SG would you use? The green or the light purple? Light purple is aluminum friendly, the green not as friendly. Would you plan on turning the engine over by hand around 12 hours into the soak?
My only concern would be my assurance of getting all the simple green out of the engine before even thinking of starting it up.
My only concern would be my assurance of getting all the simple green out of the engine before even thinking of starting it up.
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