Marvel Mystery Oil

[Joeype70]

Has anyone used Marvel Mystery Oil? I am being told to add it to my oil change on my 79 Pininfarina 2000 and to add some in the fuel tank. Many swear by it. Just want to see if anyone has and what results if any did you see? Thanks as always!!!

[aevansgatech]

I've used it both in the oil and you can add some to the gas tank as well (amount shown on the label). Can't say I noticed any real difference, but I certainly don't think it hurts!

[Joeype70]

Thanks for the feedback!

[GeorgeT]

I have used it in two cars, a 1968 Mercury Cougar 302 V8 and a 1987 Sterling 325 (Acura V6) and both had stuck exhaust valves. I replaced one quart of regular with one quart of MM Oil and the valves started functioning. If I stopped using the MM Oil the valves would start sticking within 100 miles. Both engines had hydraulic lifters so we suspect that there was some "trash" somewhere in the valve train.

[Joeype70]

Great feed back thank you!

[RRoller123]

I use it just before an oil change.

I put in about a cup or so to the oil, (even if it means slightly overfilling), then go for a 10-15 minute run on the highway (to make sure it gets really warm and flung around everywhere), then change the oil and filter.

It definitely seems to help remove sludge, and after a few cycles of oil changes doing this, my oil stays pretty clean now. The new oil used to get pretty dark quickly, but after a few cycles, it is staying cleaner much longer.

I believe that it is putting a lot of the oil pan sludge, etc. into suspension, then you drain it off with the oil change. I personally would not add it to the oil and leave it in there, as the suspended sludge particles are most likely abrasive, maybe corrosive, and will likely clog up the oil filter. Just my opinion, no data to back that up.

caveat: The high detergency of the Shell Rotella 15W-40 Diesel oil may be doing this by itself, or in concert with the MMO?

Pete

[Joeype70]

Excellent feedback Pete, thank you.

[Turbofiat124]

I tried using it as the bottle instructed in the fuel to remove carbon buildup on my Trabant 601's cylinder heads and pistons. It's a two stroker so these engines tend to need de-carbonized more frequently.

After about 1000 miles, I removed the spark plug and took a peep. I couldn't tell that it did any good.

After watching this video, I'm more convinced this stuff doesn't work. Well as far as removing carbon buildup.

https://www.youtube.com/watch?v=vVyin2n24X8

[bluespider262]

I don't think putting it in your oil might be that beneficial - it might actually do more harm than good.

If nothing else, it is simply diluting all the helpful additives in your oil so they are now maybe 75% as effective as they were before.

Modern oil seems pretty good about keeping sludge down to essentially nothing. If the motor is so bad its like jelly inside adding a quart of this stuff isn't going to help and I'm not sure I'd want all that sludge and carbon running around in the engine anyway.

[Turbofiat124]

I don't think putting it in your oil might be that beneficial - it might actually do more harm than good.

If nothing else, it is simply diluting all the helpful additives in your oil so they are now maybe 75% as effective as they were before.

Modern oil seems pretty good about keeping sludge down to essentially nothing. If the motor is so bad its like jelly inside adding a quart of this stuff isn't going to help and I'm not sure I'd want all that sludge and carbon running around in the engine anyway.

If the engine is sludged up that bad, filling it to the rim with gasoline or kerosene and letting it sit for a week, drain then repeat would probably work just as well.

[GeorgeT]

Back in "The Day" some shade tree mechanics would put a mixture of oil and varsol (mineral spirits) 50/50 in the crankcase and run for a few minutes; this would break up the deposits and solubilize the sludge. The mixture would be drained and the process repeated until the fluid came out clean. If there weren't oil in the mix, even at idle the bearings would gall.

[DieselSpider]

Marvel Mystery Oil has been around for almost 100 years now and does a good job of freeing things up.

it is made primarily of petroleum distillates, including mineral oil (60-100%), mineral spirits {10-30%}, tricresyl phosphate (an antiwear and extreme pressure additive in lubricants, 0.1-1.0%), ortho dichlorobenzene (a softening and removing agent for carbon-based contamination on metal surfaces, 0.1-1.0%), and para dichlorobenzene (a precursor used in the production of chemically and thermally resistant polymers, <0.1%).

It was originally intended for use in aircraft to help minimize carb and oiler system clogs. The pressure additives allow the thinned oil to continue providing protection against scuffing.

[Joeype70]

Great information!!! Thank you

[Europa]

You have a Trabant in the US?

I tried using it as the bottle instructed in the fuel to remove carbon buildup on my Trabant 601's cylinder heads and pistons. It's a two stroker so these engines tend to need de-carbonized more frequently.

After about 1000 miles, I removed the spark plug and took a peep. I couldn't tell that it did any good.

After watching this video, I'm more convinced this stuff doesn't work. Well as far as removing carbon buildup.

https://www.youtube.com/watch?v=vVyin2n24X8

[DieselSpider]

I tried using it as the bottle instructed in the fuel to remove carbon buildup on my Trabant 601's cylinder heads and pistons. It's a two stroker so these engines tend to need de-carbonized more frequently.

After about 1000 miles, I removed the spark plug and took a peep. I couldn't tell that it did any good.

After watching this video, I'm more convinced this stuff doesn't work. Well as far as removing carbon buildup.

https://www.youtube.com/watch?v=vVyin2n24X8

That was a video showing how a short usage of Seafoam started removing carbon from a lawn mower head so regular use before it becomes a problem would be wise. Even better though would be Berrymans B12 for that purpose. For remediation though a drip unit should be used and not the pour with a funnel method as you would be standing there dripping a whole can through the system for over 30 minutes in order to do it correctly however even with the job not being done right the product he was using did start showing improvement in the video.

The issue most have is that they do not take action to clean these things up until they have major buildup/problem to deal with. On a 4 stoke engine though much of the build up is going to be on the underside of the valves and on the valve stems in the intake and exhaust ports causing them to stick and run hot. You can see build up in thick rings making the stems look more like a poodle dogs legs.

You can see this level of build up on newer engines with only 25,000 miles on them: