Marvel Mystery Oil

BUBBA0420 · Mar 23, 2004

Has anyone ever used Marvel Mystery Oil as a
fuel additive ?? I use it religiously in my vehicles for an upper cylinder lube and cleaning agent. I have never heard of some of these additives in the Forum like Auto RX. I had a motor apart one time that I had used Marvel Mystery in and internally it was clean as a whistle. Let me know your thoughts

Bob Woods · Mar 23, 2004

Its hydrocarbon solvents, works good as a cleaner. Been around for ages, I remember it from the late 60's when I worked in a gas station. On really dirty engines we would put in in and tell the customer to come back in a week for an oil change.

[ March 23, 2004, 06:55 PM: Message edited by: Bob Woods ]

csandste · Mar 23, 2004

It did a pretty good job of cleaning an 87 Nova (throttle body f.i.?--not sure). Unfortunately the transmission went out soon after I got the engine cleaned. Do like the smell. I'd always heard that it was similar to Sea Foam-- something I've never used.

kev99sl · Mar 23, 2004

I did for a while, but it made me go through spark plugs like crazy. Other than that, no noticeable effects.

JohnBrowning · Mar 23, 2004

Funny you should mention this. I decided to do an experiment.

I have been wanting to do this for some time. I hate to waste the oil but sometimes curiosity just gets the better of me!

I have been running 5W50 in the wifes car. It has been experinceing flucuating oil pressure since I put the 5W50 in. It has also developed more varnish as visable throught the oil fill hole. Seeing how the car has been generateing negative pressure through the heads for roughly 7000 miles I felt that the varnish was unrelated.

This car does not and has never had flucuateing oil pressure. It is as regular as the north winds! SO I can only figure it is the large viscosity range of the oil!

I wanted to do two things. I wanted to see how effective cheap solvents are on cleaning varnish that AUto-Rx did not remove and I wanted to see how the vechile would respond to greatly thined out oil.

I added 1 quart of Marvels Mystery oil to the crank case. My hot idle oil pressure used to be 40-45 PSI and now it is between 30-40 PSI with even more pronounced flucuations. My average oil pressure off idle hot is normaly 65-75 psi now it is 40 psi! That is a 10-15 psi drop at idle and a 25-35 psi drop above idle at 1800-2500 RPMs.

The MMO was added to 5W50 Syntec. It has failed to reduce the varnish in the head to any amount that can be witnessed with the naked eye. It has lowered oil pressure quite a bit. It is still high enough to not be alarming in any way but the lack of positive pressure change in relationship to RPM is trouble some. IT has been in about 150 miles at 55 MPH. It will be comeing out this weekend!

The engine does not sound any different and it is not behaveing any differently since adding this to the crankcase other then the reduced oil pressure. I have checked for foaming and their is no foaming at all. I did not reduce the crankcase capacity at all. I can only imagine what would happen if you left out a quart and substituted MMO. This was with a 5W50. Can you imagine what would happen with 5W30 or 5W20 instead?

Based on this small and short test I would not recomend that any one use MMO in an engine when Auto-RX is available. Seeing how the volume is so much more reduced for things like Nuetra and Lube Control I think they would be fine. I think the total volume MMO to be used in accordance with the directions is just too much!

Take this as a Public Service Anouncement!!! What not to add to your oil!!!

[ March 23, 2004, 10:09 PM: Message edited by: JohnBrowning ]

darkdan · Mar 23, 2004

Isn't MMO really thick? So all you did was make your oil thicker.

Bob Woods · Mar 23, 2004

Isn't MMO really thick? DarkDan

If I remember right its about like 5w oil.

tenderloin · Mar 23, 2004

150 miles? How well would ANYTHING INCLUDING Arx clean in 150 miles

Bror Jace · Mar 23, 2004

BUBBA try searching this subforum using "MMO" or "Marvel Mystery Oil" as key words.

Of course this has been covered before.

--- Bror Jace

JohnBrowning · Mar 24, 2004

MMO is solvent based not gentle cleaner like Auto-Rx. MMO can be burnt in your gasoline. The solvent type cleaners often work in as little as 5-15 minutes. I have already tested B-12 Chemtool applied directly to the varnish in a small test area and it instantly disolved the varnish. 150 miles is a long time to have a solvent based additive in the system.

MMO is super thin! It is slightly thicker then kerosine. My point is that this stuff is not good to add to your oil! I do not think a 25 PSI drop in oil pressure can be called a good thing!

Any one that puts this stuff in their engine can not say that they were not warned about it's effects on oil pressure! I encourage any one with an accurate oil pressure gauge that moves in responce to rpm's to test it as well. If you have an external oil pressure guage that is even better. My Buick's oil pressure guage is not buffered much so you see readings real time.

I am going to go and change out the oil tonight or tommorow and will report back what my oil pressure changes were! I am guessing that they will return back to normal!

I belive that MMO is mostly Naptha. I belive I read that as the primary ingredient on their MSDS.

While my testing was a small sample size it is still a statement of fact! The fact that off idle oil pressure was reduced by 25 PSI is not opinion it is fact.

P.S. Origanly Auto-Rx was only used for 500 miles. So 150 miles is not that far off with a solvent based product.

[ March 24, 2004, 08:51 PM: Message edited by: JohnBrowning ]

Schmoe · Mar 24, 2004

Adding that much MMO is going to thin out the rest of your oil and oil pressure will correspondently go down as well. I"ve used this stuff as an engine fogger on my boat. Works well, better than the spray fogger from Mercruiser and quarter the price.

BUBBA0420 · Mar 27, 2004

Gentleman I don't add it to my oil I add it to the Gas for an Upper Cylinder Lubricant for the rings and the fuel injectors

Bror Jace · Mar 27, 2004

Bubba, please try that search and you'll find discussion about this stuff as a fuel additive. In my opinion, that is all MMO is good for.

I believe that MMO is moslt (60-65%) pale oil ... a thin petroleum oil. Then naptha and something else ... stoddard solvent?

A search should bring up the composition as it has been posted here before.

--- Bror Jace

pfgslg · Mar 28, 2004

Your oil pressure dropped because the oil being thinner is flowing much faster.Cant see as that is such a bad thing.If you think high oil pressure is so important put in straight 50 wt. Now when you think about that I think that we all agree 50wt. with the resulting higher oil pressure isnt the desirable result either. IMHO I dont think your hurting anything with 25 lb idle and 40lb at run speed.

Donald · Mar 30, 2004

I agree that MMO should not be added to the oil. I do not people have good results pouring MMO down spark plug holes in cases where an engine had been sitting for awhile and there was rust on rings and cylinder walls. Mostly boat engines.

CoosBayDave · Apr 7, 2004

I've been using MMO for over 30 years with good results. I run a few oz in the gas, and if pulling a trailer or hard driving I run a pint in a tank of gas. I only put it in the crankcase a day or two before an oil change. The only engine of mine that was torn down after high mileage was clean as a whistle. (57 Ford) I've helped out several people who had things like a lifter tick on start up with it in the gas and just before a change. I buy it at WallyWorld, it's in-expensive, and I've seen it work in dozens of cars. I know several people that put a couple of tablespoons of MMO in their manual trans and differential. I gave my Camry to my daughter over a year ago, it had 420,000 on it and passed Calif. smog.... It's still running great she drives it every day.
The company gave me an overhead oiler in '72, it's now on my '82 Chevy van and it runs good at over 250,000. I am basically against MOST additives, but have proven to myself that a FEW do work.

Bror Jace · Apr 7, 2004

CoosBayDave, I think you've had luck with MMO in the crankcase because of the amounts you are using. You use small amounts diluted in a full sump of motor oil and it is only in the crankcase for a day or two.

I don't recommend doing this to others ... although I've done the same thing myself.

The key is to use MMO sparingly in this role.

--- Bror Jace

Gary Allan · Apr 11, 2004

I don't have the can in front of me (I add it to my oil burner fuel oil) ..but I seem to recall that only 10% was recommended for crankcase additions. 1 quart in 5 reads like a double dose to me.

I've never used it as an oil additive.

Marvel Mystery Oil

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