Marvel Mystery Oil

[TommyDodge]

I am hoping that it is ok to post this question here since it doesn't "fit"
any other category that I can see.
My engines in both my vehicles are old and either use or leak oil, or both.
I remember reading someplace about Marvel Mystery oil, and can't remember where it was.
I looked at the bottle and saw you can use it in the gas or with your oil, or both.
I am curious as to whether any of you on here use it, or have used it in the past, and what your thoughts on it are.
Not to be smart, but I don't make enough money to throw any away. I am somewhat leery of "miracle products"Thanks in advance
Tom

[Tom Petroff]

I remember Dad having Marvel on the shelf at his Shell stations back in the 60's .
As you know it been around for a Long time.
I have only used it in old partially stuck engines I was trying to revive.
IMO
Stuff like this and Sea Foam or anything that claims can be used in both fuel and oil
I use with Extreme caution and usually only in the fuel.
Reason being you want to be very careful putting chemicals in the oil that can clean,and loosen sludge and varnish.
In your case I would add heavier oil,and something like STP or Lucas to help keep the viscosity high.
And then there's a whole new debate.lol
I'm just not a believer in most "snake oils"
Tom

[John Waak]

I researched Marvel Mystery Oil about 15 years ago. What I remember is that it is basically a very high grade, light weight (5 weight) oil, and a wintergreen detergent. Not a lot of mystery to is actually. At the time, even the FAA was ok with it for use in air planes. Used as directed in an engine that is relatively clean, it will remove minor tarnish, and also lubricate.

I used it in both the crankcase and fuel tank of a VW diesel. Along with regular oil changes and fastidious maintenance, the engine still met VW factory specs for new at 225,000 miles. Whether the Mystery Oil did any good, I don't know. It didn't seem to do any harm. As mentioned above, I would not recommend using it in an engine that might have heavy deposits lingering around inside.

[Gordon Maney]

First, yes, this is a great place for the question! We are all about questions here, so ask away....

My calculator tells me I have had an earnest interest in automotive repairs for 48 years. At the age of 14 I became a sponge, learning all I could. Marvel Mystery Oil has been around for a very long time. I have fond memories of the appearance of the can.

In 48 years I have never used it, and I have never seen anyone use it. I have seen many people who had some, and I believe I have some. I can't recall how I came by it, but I got it somehow. Being a pack rat, I keep it in case I ever need it.

We live in a market place that sells all kinds of products that are supposed to be capable of all kinds of things. Many of those products don't achieve the purported results. Marvel Mystery Oil is said to be good for what ails you, in a manner of speaking. Meaning, good for everything.

I have nostalgic feelings about it simply because it has been around for so long, and I can't even say why. I also have nostalgic feelings about 3-in-one oil. I first saw that as a little kid. My dad used it in knife sharpening, and it has a distinctive smell.

OK, so I am a bit worried I am sounding sarcastic here and that is not my intent, truly. Sometimes marketers try to sell us things we don't really need in the first place. I am not sure we need it.

Recall STP. A can of really thick stuff you poured in your engine. A web search tells me it is still sold. At one time I used it as an assembly lube in engine building. Many did. Then I read something that said under certain circumstances using straight STP as an assembly lube resulted in some sort of granular, slightly abrasive substance forming and damaging bearings. Supposedly it needed to be mixed with oil. I can't say if there was any truth to that, but I stopped using it and move on to Valvoline X-all grease. Non-melting but oil soluble. The only thing I used oil on were the rings. A web search tells me X-all is no longer sold, but it is sold on Ebay as automobilia. Antique cans of old grease? Who'da thunk it?

OK sorry, rambling.

I don't know that I will ever use the can I have, but I do intend to keep it, even if only to sell it on Ebay someday.

[DrPepper]

I keep a can on the shelf all the time...

never put it into my oil or gas, but I have used it exclusively in my 1970's real Chicago Pneumatic 1/2" impact that I bought new. The tool still works great. I use it sometimes for a penetrating oil, seems to work real well.
If your engines are old and either leak and/or use oil, MMO isn't going to make them new again. Sorry...!

Best of luck,
DrPepper

[Gordon Maney]

You remind me, I have seen it used as an air tool oil.

[Chris Olson]

I have used it to free up engines that have been sitting for a long time just to lubricate the cylinders as you Bar over the engine, It claims to free up stuck rings so I guess it wouldn't hurt... most of it probably sprays out when I would spin the engine on the starter with the sparkplugs out.

[Charles Talbert]

Many differing opinions

Maybe that's why they call it mystery oil.

I've used most everything on the market at sometime over the years, lots of claims; some seem to work , some didn't. I can say this for a fact though; there is no miracle product to repair a badly worn engine that either already does or soon will need a rebuild. I'd put my money toward the rebuild if a compression test pointed me in that direction, rather than hoping for a miracle if the engine has seen its better days.

Now if you are trying to free sticky rings, etc, in an engine that should have life remaining, that's another story, however better products than Mystery oil are out there for that purpose these days.

[NNICKB]

Now if you are trying to free sticky rings, etc, in an engine that should have life remaining, that's another story, however better products than Mystery oil are out there for that purpose these days.

I had very good luck using Liquid Wrench to free up the engine in my Dodge when I first got it. It is harder to find than the ubiquitous WD40, but much more effective. I also use automatic transmission fluid to clean and lube crusty parts.