Community Forums

tuffr2 · 04-24-2016, 02:52 PM

Good idea or bad idea. A friend is thinking of doing this on his 2003 Ford Diesel with the trouble prone engine.

Anyone doing this?

tombones49 · 04-24-2016, 03:38 PM

Marvel Mystery Oil is a very old product that is still being made today. Basically it is very lightweight oil with a chemical compound added. That chemical compound causes rubber to swell. Rubber "O-Ring" seals in valve guides was the the original intended target. Additional targets are other rubber seals and rubber gaskets. When added to gas or diesel fuel it will clean carburetor jets and now, fuel injectors.

If your engine sends out a puff (or a cloud) of smoke when pulling away from a stop light or when starting the motor after sitting for awhile, Marvel Mystery Oil added to the crankcase oil will probably help lessen the problem. It is not an overnight fix, give it a week. Note that some valve guides have nylon or composite O-rings which Marvel Mystery Oil doesn't affect.

Best wishes, Tombones49

wingnut60 · 04-24-2016, 07:24 PM

"trouble-prone engine'? is he having problems are thinking he will head them off?
Can't see where this would help with the 6.0L problems I am aware of.
Joe

tuffr2 · 04-24-2016, 10:54 PM

Would it keep the injectors cleaner? That would help the engine...correct?

1bigmess · 04-24-2016, 11:07 PM

Injectors would normally be clean. Usually if you need a "mystery oil" to keep the engine running well or well enough, it would be better to find and fix the main problem instead of pouring band aids into the fuel tank or oil.

lynnmor · 04-25-2016, 03:37 AM

The older diesels used fuel with a higher sulfur content. That fuel is not available at most fueling stations today. The sulfur added lubricity. The newer diesels have emission systems that require ultra low sulfur fuel and will not tolerate additives that weren't designed for them.

Highway 4x4 · 04-25-2016, 11:09 AM

I had a 03 Cummins and I added lots a stuff, MMO also, to the fuel tank with no issues. I now have a 14 and will never put anything but the best #2 diesel I can find in it. With all the new smog devices the days of fuel additives are over, for me.

chertz · 04-25-2016, 03:25 PM

Ditto what highway said... my 05 cummins ate a steady diet of fuel additives due to being designed pre-ulsd. My 14 just eats clean #2, except in winter she will get some anti-gel.

Dave-R · 04-25-2016, 08:26 PM

In my days, I have used it to free sized engines. Mainly when the rings have stuck to the cylinders in marine engines. That it does . Anything else I would question. Dave-R

Ste · 04-29-2016, 05:41 PM

Search online for stiction additive(it is real!) Some International engines with HEUI injectors needed this to run properly. Helps with lubricity which is a real concern as the lubricity rating that is "acceptable" for most fuel refineries is lower than the minimum requirement that engine manufacturers want.