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bobar

Marvel Mystery Oil to unstick ring on piston

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i have an '85 22re with 2600 miles on it using about 1 qt of oil every 500 miles had a compression test done 140,135,100,140. I have been told i may have a or some stuck rings. I have been told that i can take the plugs out and soak each piston with marvel mystery oil over night (crank the motor over with the plugs out then put them back in) then change the oil and add a qt of mmo run it for 3000 miles and it may fix or help it. Any thoughts about this thanks!

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i have an '85 22re with 2600 miles on it using about 1 qt of oil every 500 miles had a compression test done 140,135,100,140. I have been told i may have a or some stuck rings. I have been told that i can take the plugs out and soak each piston with marvel mystery oil over night (crank the motor over with the plugs out then put them back in) then change the oil and add a qt of mmo run it for 3000 miles and it may fix or help it. Any thoughts about this thanks!

My "thought" is it's a waste of time. But probably won't hurt anything either; Having one cylinder 40 PSI lower then the others is usually indicative of a valve problem or ALL rings on one piston stuck. One ring stuck or even missing completely won't lower the compression that much. Easy to verify. If it's NOT a valve problem, and you squirt some motor oil into the cylinder, and then check, the reading should climb right up where the others are. If adding oil does not increase the reading, it's a valve/seat issue.

Hopefully when the compression check was done, all plugs were out and cranking RPMs were at least 400 RPM? Also the valve lash was checked to verify all valves are actually opening and closing as they should and when they should? Valve lash determines valve timing.

I've had to pull out pistons to free struck rings and I'll tell you this. Nowadays with an engine that's been run with high-detergent oil (and just about all engine oil for highway use is), the rings IF stuck, usually have to be pried out due to mechanical damage to the aluminum piston groove. Not stuck from sludge. I've had a few modern engines that had stuck rings due to being not run for 10-20 years and getting water in the engine. With them, I had to break the rings to remove, recut the piston ring grooves, and then install a Hastings ring-groove repair kits.

I'll tell you something I've seen work on rings that were not seated properly, but am NOT recommending it. Just commenting that I've seen it work for a "short term" fix. It was done in a diesel shop I worked in for engines known to be fairly unworn but oil burners. That was caused by unseated rings, not stuck rings. A bunch of Bon Ami detergent would get dumped down the air intake while the engine got revved up. It's kind of like running liquid sandpaper through an engine. It scours the cylinder walls and causes some "controlled" wear. It works short term in some engines but in the long run - probably not a great thing to do. I would not do it to anything I wanted to keep a long time.

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Bon Ami I heard that story years ago, and tried it, you will be putting more than rings in it, it will mess up everything. You may have heard of dusting a eng Air filter with a hole in it in a dirty environment or not seated properly, Thats what happens with Bon Ami.

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Bon Ami I heard that story years ago, and tried it, you will be putting more than rings in it, it will mess up everything. You may have heard of dusting a eng Air filter with a hole in it in a dirty environment or not seated properly, Thats what happens with Bon Ami.

Not exactly. Dumping Bon Ami into the air intake of an engine is somewhat controlled. Driving down a dirt road with a bad or no air cleaner, is not.

Note that I DID say it was like dumping liquid sand paper down an engine and did NOT recommend it to any Toyota owner. I stated I've seen it done. I've also seen it work for its intended purpose. That purpose is to help seat rings that are fairly unworn but glazed, i.e. were never broken in properly. Can't say I kept count but I've probably seen it done over a dozen times. In the late 70s, John Deere had a mess of new engines burning oil and using Bon Ami was one of the suggestions from a Deere engineer. They had little to loose because if we tore any engine apart, it would automatically get new pistons, rings, and sleeves anyway.

Bon Ami had some specks of feldspar in it. A little bit put in the air intake did stop excessive oil consumption in a few machines. In the others - after the treatment they were no better, and no worse. Those wound up getting torn apart for new set of pistons, rings, and sleeves.

You said you heard the story and tried it, but did not mention what the problem was to start with. I also assume you are talking about one attempt?

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Iron bores iron rings maybe but not likely don't even think about trying it on a modern engine unless you are planing on reboring it any way. The old timer's used to try that trick by the time our machine shop got the engine it look as if some one had run a rat tail file down the cylinders bores. Rings don't stick unless there is a reason. Marvel Mystery oil used to be an old time fix it did not work either.

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Bobar;

It won't hurt. might help. What the heck, try the $8 fix before you do the $800 fix.

Each cylinder should hold an ounce or two. Do NOT install the plugs. crank the engine for 30 seconds, then let it sit for an hour or two (or a day or two). the longer you can do this, the better, a week or two, go out and crank it whenever you get a chance.

when your ready to give it a try, put the plugs in it and fire it up. It will smoke like hell for a few minutes to burn out the mystery oil.

Good luck

John Mc

88 Dolphin 4 Auto

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Iron bores iron rings maybe but not likely don't even think about trying it on a modern engine unless you are planing on reboring it any way. The old timer's used to try that trick by the time our machine shop got the engine it look as if some one had run a rat tail file down the cylinders bores. Rings don't stick unless there is a reason. Marvel Mystery oil used to be an old time fix it did not work either.

No diesel we ever worked on had cast iron rings. All were at least chrome plated (top rings) and most were plasma-Keystone rings. The old low compression gas engines - yes. Built with soft cast iron rings and hardened cylinder walls. Designed to wear rings before the cylinders wore. That design was done so an owner could repair his/her own engine without special tools or machinery.

None of my comments about Bon Ami had anything to do with ring sticking anyway. Just in certain situations to promote ring seating. I saw it work a few times. We had a full service automotive machine shop besides our general repair shop. I can't say I recall anybody bringing anything to our machine shop that was working well before they tore it down. I.e. if someone had successfully conducted some sort of remedy on their engine at home - and it worked - they would not then come down to our machine shop to tell us their success story. We dealt primary with worn parts and bad news. We rebuilt fuel injection pumps, hydraulic pumps, cylinder heads, did engine boring, rod resizing, rod rebushing, etc. Even knurled piston skirts and recut piston lands on the old split-skirt cast-iron pistons.

Our repair and sales shop was a different story. We got to see the failures and the success stories. Standard procedure for a engine known to be fairly unworn but burning oil was to put 10W pure mineral oil in the crankcase and then run it for a half a day on a dyno with intermittent loading. The idea was to promote some controlled wear to get the cylinders to seal. If that had no positive effect - we either tore it down - or if we owned the machine (not a customer's). we might dose it with Bon Ami. I saw a few that improved afterwards. I also saw some that did not. I saw none that "self destructed" and got worse - but we careful with what we were doing. Can't say what some others have done to destroy their equipment.

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Many OEM engines even to this day still use premium grade iron compression rings including diesels the scrapper and oil control rings not as much as they once did. There is no way having rebored more then one engine trashed by Bon Ami I would ever consider it under any circumstances. Did they dump too much in who knows how much is too much? If an engine even a new one is burning oil to excess there is some thing wrong with it and it needs to come apart.

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2600 miles? curious if this engine has been sitting.... I got an old ford running that had set for a few years - after running it some the compressions improved a lot

Another approach is to pull the 4 spark plugs - use a fitting (aviation is one source) that pressurizes each cylinder (with piston at TDC) and listen to the 3 sources for leakage (tailpipe, air intake, oil fill cap). If you hear/ fill air hissing out of one or more of those you can have a better idea of what you are dealing with,

The only way I see marvel mystery oil helping is if you have a scenario were the engine has not been run for a while and rust has set in.

I used ATF to get my engine moving. It smoked like hell but it worked.

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just got my rv back from being worked on and discovered that i was wrong about the compression numbers should be 120,100,120,120. does this change any ones thoughts. The rv runs good and i have climbed some big mountains for arkansas (2700 ft) with no problems. i have drove about 2000 miles i don't know how long it may of set up. thanks

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just got my rv back from being worked on and discovered that i was wrong about the compression numbers should be 120,100,120,120. does this change any ones thoughts. The rv runs good and i have climbed some big mountains for arkansas (2700 ft) with no problems. i have drove about 2000 miles i don't know how long it may of set up. thanks

I'd drive it and not worry about it - other then making sure the valve-lash was adjusted properly. If the low cylinder was being caused by a valve too tight. continued driving could burn it up. As I stated earlier squirting some motor oil in the low cylinder and then taking a compression reading will usually tell you if it's a cylinder - or a valve problem. If a cylinder problem, compression will rise after adding oil. If from a leaking valve, it won't.

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when i was doing a used car business my main mechanic was a toyota truck specialist.

What he used for stuck rings was actually brake fluid. its going to work a lot better with the whole head off.

thats what he did Im not sure of the logic involved but he worked on millions of them.

obviously changing the oil a lot afterwards whether it works or not is pretty key.

that being said... I never let him do that to any of my cars I took to him. mechanics have a different definition of fixed than I do sometimes.

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to the best of my knowledge marvel mystery oil is essentially kerosene.

It is on the milder scale of the additives you can use. so while it is not likely to hurt its not likely to be the extreme fix you need.

Ive poured bottles of this stuff into carberators and it made no difference where as something a little more caustic like sea foam would.

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