Marvel Mystery Oil as a motor flush? We try it out!

One of the downfalls of buying a used car from a dealership is that you have no idea what the maintenance history is. This is especially true of oil changes. Did they use good oil, the right oil or did they change it on time? I've used Marvel Mystery Oil as a motor flush every time I buy a new car and I've had awesome results. The wife just purchased a 2017 Nissan Rogue so I decided to use this as a test vehicle for this process.

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[FrenchyCanuck]

I used it in my wife’s car and it helped a lot with tic and the oil went so dark it was insane. Now it runs smooth and the oil stays clear.

[TainoXtreme]

They all came out darker because Marvel mystery oil remove some buildup from the inside of the engine. Very good video. I appreciate your sharing this video. God bless you.

[heavymechanic]

Back in the day MMO came in a metal can and recommended 4 oz per quart of oil, I still use that amount with great results. MMO cleans oil deposits and reduces drag on the rotating assembly. Use MMO annually and leave it in for 1K miles as a minimum for great results. I even use this stuff in my mowing equipment (gas + Oil) and have fewer problems.

[thesetruths]

I have a 2005 5.3L automatic 4x4 Yukon with 223, 000 miles. It holds 6 qts of oil. I changed oil (10w30 conventional) and filter (walmart brand base filter) before a 6, 500 mile mostly intestate trip from CO mountains to Mid-Atlantic to South and then back up to CO mountains.

In the first 4, 000 miles of trip Yukon burned 1.75 quarts of oil. Before making the last 2, 500 miles of trip (uphill to CO) I added .75 quart MMO (conventional formula) to bring level to Full.

It burned none in 2, 500 miles to and around CO before I changed the oil/filter. So it went from burning 1.75 qts in 4, 000 miles mostly downhill driving to not burning any in the next 2, 500 miles of uphill and mountain driving.

On the trip I averaged between 16.8 and 18.1 mpg, checked by gallons and miles tracking and compared to vehicles MPG gauge. The computer was very close, always within .1 to .2 mpg.

Can someone explain this dynamic?

I'm going to test it again on another 3, 500 mile road trip soon to South and back to CO again. If I have to add a quart I'm going to add 1 qt MMO to see if it stops the consumption again.

[imgonnagogetthepapersgetth]

I love the southern accent EXCEPT the "ol" instead of "oil". Thanks for the vid.

[donaldburton]

I put a half a quart of marvel mystery oil in my honda vtec every 3k . It runs so quiet . I bought the car with 50k on it and my first 3 oil changes at 3k came out black ., now at 140k every oil change comes out very light brown .
2 thumbs 👍 up .

[franknew]

I have a 2002 Chevy truck that now has 146k miles on it. About two years ago, it had a noticeable lifter ticking noise. It was a quart low on oil, so I added a quart of Marvel Mystery Oil to the crankcase. A few weeks later, the lifter ticking noise was gone. When I next changed the oil, it was the dirtiest I've ever seen it, telling me that the MMO was cleaning some of the sludge out of the engine. Now, once between oil changes when the truck is a quart low on oil, I add a quart of MMO to the crankcase for preventative maintenance.
I have also been adding MMO to the gas of my car, truck, and lawn mower at every fill up at 4 ounces of MMO for every 10 gallons of gas since 2016. Since I started using MMO in the gas, my car's highway miles per gallon has increased by at least an extra 1.5 to 2 mpg. With Walmart selling the quart size of MMO at $3.88, I am actually saving money using it, as I am now using less gas.

[williamoneal]

I approach in a different way. I get a full gallon of diesel fuel. When changing oil ..I do this.
Drain old hot engine oil. Leave drain plug out. Now take gallon of diesel fuel and add to engine.
Do not start engine. I am just flushing out oil pan. Much sludge and gunk will drain from oil pan.
You have now cleaned up pan. You may do this method as often as needed. Also you may
Strain the old diesel fuel so no sludge or gunk is present. Now you can use this again for
cleaning your oil pan. Works for me. This will not harm engine as you have not run your engine
with diesel fuel, only flushed your oil pan. No harm done to engine. 😊😊

[billlincolnmd]

I just used a quart of MMO with four quarts of conventional oil in a toyota engine
badly gunked-up from neglect. After running 500 miles I dropped the oil which was
filthy. Put new oil in and the engine is smooth and runs excellent. MMO dissolves
varnish and frees up valves, rings and reduces deposits. Great product. Love it.
Also, improved compression.

[jake]

I've been running about 15% MMO in my girlfriend's Chevy Prizm, it was not terribly bad in terms of carbon, but when I did the valve cover and top end was very varnished. In 5k miles, there's no longer hardly carbon where there previously was.

[TanManFixes]

MMO is amazing stuff. You can also use .5-1 quart of automatic transmission fluid. cleans the motor VERY well.

[Ian-ijof]

I use atf, 1 litre in with oil for 50 to 100 miles, seems to get rid of everything and the new oil stays clean for at least 1000 miles, even after 3000 miles its still pretty good.

[northwestmechanic]

I will be putting in a full quart of MMO in our 2017 Mitsubishi mirage g4 at the next oil change in a couple of days. I will also be filming it too. I also have to replace the coolant at 120, 000 miles too. But great video man. I subscribed.

Update. I did make the video and after putting it in, our car sounds a lot better.

[michaelquillen]

MMO is quite gentle and slowly liquefies the gunk in the engine. I've been using it since the 80s. With today's modern synthetic oils, it's probably overkill. Nevertheless, about 500-1000 miles before I change my oil, I top off the crankcase with MMO. Never had an oil-related problem with an engine.

[Ifyoucantdodgeitramit]

Gotta be careful running full synthetic in a car that's always had cheap conventional oil. Synthetic oil has more detergents in it to help clean the engine which is a good thing. However, in a lot of older engines some of that sludge at the bottom of the oil pan can actually help to stop leaks from poor maintenance. If you switch it to synthetic (same as what he said in the beginning of the video about engine flushes) it can clean some of that sludge away that was helping to plug those leaks. Secondly, synthetic oil is slicker. It's NOT thinner, as some people think, but its SLICKER. So on top of cleaning up those sludge areas, the slicker synthetic oil can find weak spots that conventional oil couldn't, and also cause leaks. I would suggest on an older unknown engine running synthetic-BLEND if you're gonna run any kind of synthetic at all, also try to find a syn-blend that's high mileage. High mileage oil has additional addatives to help seals and gaskets "swell" and help stop leaks. I'm not saying every engine is gonna have a problem switching to synthetic after poor maintenance or high mileage. I'm just telling you it COULD. There's thousands of additives, oils, filters, flushes, etc. Honestly there is no definitive combination that works 100% of the time for every car. They're all different. All you can do is try stuff.

[konstantinostselios]

Yes that's good stuff my mercedes e320 have a lifter ticking colapsed and I put 2 quarts in with motor oil I'm running it for about 3k miles and the ticking almost gone

[scottmingersoll]

I would have went with at least a 5w30 being the MMO thins it out so much. When I use it in my F150 i always mix a little Lucas in because it really brings the viscosity down to a level I’m not confident with.

[JA-rnqv]

Those Nissan's are notorious for transmission failures, make sure you change the trans fluid every 30k to 40k miles max.

[chuckspeer]

I agree tried it works great cleaning sludge

[lobbyrobby]

I have a 2011 f150 5.0 that is close to 100, 000 miles. I use heet in the winter and occasionally dump in some seafoam. I'm good with maintenance and even occasionally send in oil samples. I'm going to start using this in the gas and maybe add some to the oil before my next change.