AutoRX seem to be effective at removing sludge. Is there a product that can safely remove hard, coking-type deposits?
Coke removal
- Thread starter GMorg
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Why worry about those deposits?
Start using a synthetic oil, practice a reasonable OCI based on time or mileage, and forget about it.
And if you want, prior to an oil change, toss in a quart of kerosene or biodiesel, as a 5-10 minute no load cold engine flush!
Start using a synthetic oil, practice a reasonable OCI based on time or mileage, and forget about it.
And if you want, prior to an oil change, toss in a quart of kerosene or biodiesel, as a 5-10 minute no load cold engine flush!
Bingo!
Yes, that is how it comes to me. It is called a flush, simple one and call it a day.
If you use a good oil from the start, coke is not an issue. At least it was not for me in 100K miles on a Powerstroke.
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Folks, just a bit related to this subject here:
Recently, I've been dealing with a friend's Vee6 with minor oil burning issues (oil seeping through oil control rings, compression rings, etc., 1qt per 4000kms, you can smell the oil smoke from exhaust, etc.) and I was looking into Molasoak and for possible remedy (I'm aware of AutoRx in cleaning out the oil control ring deposits, thus restoring proper oil scraping functionality, etc. but I'm saving this option until later).
For a bit of experimentation, I filled 2 oz LC into a glass mason jar and then put some of my old Coleman carboned up lantern generators in it and let it soak for several days (try to figure out if Molasoak actually work in dissolving deposits trapped in piston ring grooves) but with very limited success:
After several days of soaking, those carbon deposits on the copper lantern generator surface faded a bit but not by much; on the other hand: steel parts previous coated in light rust or deposits seem to be working out fine. I tried introducing larger piece of carbon deposits I scrape off of an old intake valve into the jar of LC and then let it "melt" but to my surprise, it doesn't seem to "dissolve" at all.
Please advise...
Quest
Saving my precious AutoRx as a very last resort...
Recently, I've been dealing with a friend's Vee6 with minor oil burning issues (oil seeping through oil control rings, compression rings, etc., 1qt per 4000kms, you can smell the oil smoke from exhaust, etc.) and I was looking into Molasoak and for possible remedy (I'm aware of AutoRx in cleaning out the oil control ring deposits, thus restoring proper oil scraping functionality, etc. but I'm saving this option until later).
For a bit of experimentation, I filled 2 oz LC into a glass mason jar and then put some of my old Coleman carboned up lantern generators in it and let it soak for several days (try to figure out if Molasoak actually work in dissolving deposits trapped in piston ring grooves) but with very limited success:
After several days of soaking, those carbon deposits on the copper lantern generator surface faded a bit but not by much; on the other hand: steel parts previous coated in light rust or deposits seem to be working out fine. I tried introducing larger piece of carbon deposits I scrape off of an old intake valve into the jar of LC and then let it "melt" but to my surprise, it doesn't seem to "dissolve" at all.
Please advise...
Quest
Saving my precious AutoRx as a very last resort...
Thanks for the wonderful tips on preventing coking, but my question has to do with removining it. The question applies to used cars with unknown history and obvious thick, black, hard, flush-resistant carbon build-up. I have not seen a product that will actually remove this type of stuff without tearing the engine apart first. I was hoping that some else had seen such a product. My concern is that small oil passages may be restricted. I am not the sort that wants shining innards. However, I do like the idea of good oil flow.
GMorg, some folks have discussed the idea of draining the oil and literally filling the crankcase up with kerosene or biodiesel and letting it sit overnight. I don't know about that though as, when I dropped my oil pan, I tried to use a spray bottle of diesel to clean things up. It didn't seem to do anything and I ended up wetting a rag with chemtool. It cleaned things right up but it seems it needs to be fairly undiluted to do anything.
When I took my infamous pic of the bottom up view of my engine inards, I had already done a chemtool flush, 2 arx runs, and an LC treatment or two.
But, yes, if you buy a used car, your hands are tied and you have to make due with what you get. On the bright side, this SAAB has not seemed to be affected by it's sludgy past. MPG is excellent and there doesn't otherwise seem to be any serious problem. I've put 40k miles on it since I got it a year ago Saturday.
When I took my infamous pic of the bottom up view of my engine inards, I had already done a chemtool flush, 2 arx runs, and an LC treatment or two.
But, yes, if you buy a used car, your hands are tied and you have to make due with what you get. On the bright side, this SAAB has not seemed to be affected by it's sludgy past. MPG is excellent and there doesn't otherwise seem to be any serious problem. I've put 40k miles on it since I got it a year ago Saturday.
That's interesting. As a Passat owner with the 1.8t engine I'm familiar with tales of woe regarding coke / sludge clogging the screen to the oil pump. Given that you have to either raise the engine or remove the subframe to get to it for replacement I've been wondering lately if you couldn't just drain the oil and pour a solvent down the dipstick tube -- just enough to cover the oil pump screen -- and let it sit for.. well, days really if that's what it takes. I'm certainly not enough of a mechanic to recommend this to anyone but if that issue happened to me (knock on wood) I might just have to give it a shot.
I believe the wording on the LC20 jug states that it helps dissolve "carbonaceous" deposits. Whether that includes bona fide carbon or not, I don't know. My feeling is that it ought to.
Is it possible that there was not enough heat for the LC20 to "melt" the carbon you speak of? I've been out of the loop on this stuff for a while, but I've always been under the impression that LC20 becomes more effective with heat.
Is it possible that there was not enough heat for the LC20 to "melt" the carbon you speak of? I've been out of the loop on this stuff for a while, but I've always been under the impression that LC20 becomes more effective with heat.
I don't see any point on 'soaking'. Most solvents become more effective with heat and movement.
If you want to fill your engine with gallons of solvent and let it sit, add an airline tube through the dipstick. The airflow percolating would help. Having an oil pan heater to warm the solvent should help even more.
Otherwise, don't bother. Stick with better oils, more frequent OCIs, quick flushes, or oil additives.
If you want to fill your engine with gallons of solvent and let it sit, add an airline tube through the dipstick. The airflow percolating would help. Having an oil pan heater to warm the solvent should help even more.
Otherwise, don't bother. Stick with better oils, more frequent OCIs, quick flushes, or oil additives.
Normally, I would just consider tearing it down and then blueprint/rebuild it (LOL! this is my favourite part). But with this friend's engine he has not decided yet as to how much $$ he wants to spend, so a bit of chemical help should get him going.
Thanks for the good tip though. I tried soaking an old sparkplug and it does help in dissolving/dislodging some carbons and brownish gasoline related deposits, which is kinda reassuring. I just need to find time to do the Molasoak now to see what happens.
(*bet ya the oil control rings been jammed due to excessive deposits*)
Thanks for the good tip though. I tried soaking an old sparkplug and it does help in dissolving/dislodging some carbons and brownish gasoline related deposits, which is kinda reassuring. I just need to find time to do the Molasoak now to see what happens.
(*bet ya the oil control rings been jammed due to excessive deposits*)
One flush ain't gonna do it if the engine is gunked up. It may clean out the rings but if your worried about the residual deposits rolling around in the pan, well...
When I removed the oil pan in my SAAB, there were pea sized hunks of carbon that could have been mistaken for those little hunks of coal you used to use in aquarium filters. No flush or arx was gonna dissolve that.
When I removed the oil pan in my SAAB, there were pea sized hunks of carbon that could have been mistaken for those little hunks of coal you used to use in aquarium filters. No flush or arx was gonna dissolve that.
I started burning oil after a molasoak, be careful.
Shaman-
How's your PCV valve coming along? Any luck finding one so far?
Quest
How's your PCV valve coming along? Any luck finding one so far?
Quest
If it were my engine, I would do what Frank (as in Frank is the oil guy) once did. I would add a container of Neutra and AFT and to the oil. There was a before and after picture of his results. Good luck.
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