marvel mystery oil

[xvr843]

Using Marvel Mystery oil in motor and gas tank. Does this stuff really works?

[Bonnefied_GM]

The old guy I work with at the shop who maintains the company vans and various other stuff SWEARS by it. Claims it completely quieted a bunch of valvetrain clatter that one of the vans had (all Chevy's and GMCs). Granted, he said it did it over time with successive oil changes. I personally don't feel comfortable using cleaners and whatnot in my motors, but don't let me change your mind

[willwren]

It won't quiet valvetrain clatter if you put it in the tank. You have to put it in the OIL for that to work.

No, don't add anything to your fuel or oil unless you need a short-term bandaid for a failing motor. Additives of any type just empty your wallet and generally don't do you any good under the hood.

[LeSabre in Buffalo]

Look over at Bob is the Oil Guy's forum section to see if it works. It's been covered about 30-40 times in exhaustive detail over there.

Short summary: It works as advertised. It also needs time, such as over an oil change, to work in the oil. In the gas it's more of an upper cylinder lubricant than a cleaner.

I used it in the gas, and found it to be very fiddly regarding dosing. Too much and fuel economy went down. Too little, and there was no effect. I'm planning on using it in the oil in my mom's car to de-gunk that poor Scooby's EJ22 that sees only short trips at light throttle.