MMO is Marvel Mystery Oil. It's a fuel and oil additive you can buy at Walmart or most any parts store. It has been around since the 1920's and is a great fuel system additive. I use it in my fuel all the time, occasionally I put a pint in my oil. I don't talk about MMO much on here. Some people do not like fuel and oil additives much. I have not seen it here on DF much but on other boards additives and those who use them get beat up a lot. I use MMO, have been using it a long time and it sure helps my truck run better. It costs about $4.00 at Walmart and about $5.00 at parts stores. One quart lasts me several months and it does a good job, not only in my truck but also in my lawn mower and chain saw too. My mower always starts up on the first pull, even after sitting all winter without being used at all.

Jimmy

 

Thanks again for all the advice Jimmy. You always take the time to write very precise and well thought out posts. I enjoy reading what you have to say and have learned a lot.

When I change my oil before winter, I'll substitute a quart of MMO.

If I add MMO to the gas at every fill, how much do you add?

Some people were meant to live in the south, some people were meant to live up North. I was one of those people meant to live up North. I love the cold. I love the snow. I've been to FL several times since my sister lives there and hate it!

 

YW Brad. Glad to help you out. With adding MMO to the gas, you need to first use a good strong Polyetheramine (PEA) based cleaner like Regane, Regane High Mileage (has more PEA than regular Regane) or you can use Techron Concentrate or Red Line Si-1. Those are really the only fuel treatments out there that actually do any good. If you can find BG-44K for sale somewhere or maybe find it online, it is real good too but is real expensive. The other cleaners like STP are mostly just kerosene. Lucas fuel treatment is mostly just a light oil and not much else is in it. Once you run out the tank with the cleaner in it, then you can start your MMO regimen. The idea is to use a good cleaner first and then keep it clean with regular use of MMO. You could even take it a step further and have a good fuel induction service done, like the BG or Everwear service you can get at a lot of tire shops. BG is great but is not cheap. You can look at www.bgfindashop.com for more info and maybe call around about it. Some tire shops down here do the Everwear service. There is also a DIY home fuel induction service kit from 3M that you can buy at Autozone for about $30.00 but I have no idea how good or bad it might be. Most 3M products are always good though.

After the fuel cleaner you need to make your first dose of MMO to the gas tank proportionate to the tank capacity. The recommended MMO dose is 4 ounces to every 10 gallons of fuel. So if you have a 22 gallon tank, the first dose should be a little over 8 ounces. After that you dose the amount of fuel it takes to fill up. I always fill up when I get to the 1/4 tank mark on my fuel gauge. I know from experience that it will usually take about 15 to 16 gallons to fill up from that point, so I add 6 ounces of MMO to the tank before I pump the gas in. I have done some experimenting with the dose and found that to be the best dose to get the best results in my truck. I carry the MMO with me in an old Regane bottle, it is real easy to carry and add to the gas tank that way.

The trick to using MMO in fuel is that you have to be consistent with it. You have to add it at every fuel fill otherwise you may see reduced benefits or no benefits at all. It also may take you a few tanks before you notice any improvements. It did with me, about the time I was on my second tank of gas with MMO I found I had a lot smoother and steady idle, my throttle response was better, truck felt like it had a bit more get up and go and a nice side benefit was I got about 1 or 2 more MPG. I track my MPG on www.fuelly.com. My truck also starts easier with MMO in the gas. It only takes just a half-second blip of the key and it fires right on up, every single time. MMO helps to combat the negative effects of ethanol in gas, and it can help restore the lubricity that is lost in ethanol based fuel. It lubes the fuel pump (so it works better and has a longer life span) and helps keep the injectors and fuel level sending unit clean. MMO is not as strong of a cleaner as PEA but it will help keep an already cleaned injector clean for a long time.

This may turn out to be a longer post than most others but I will tell you that around 50,000 miles my truck developed the preignition ping that 3.9's are known for. I tried a lot of things to get rid of it, including the BG and Everwear fuel services. I finally put in a 180 degree thermostat and a set of 3923's. That got rid of the ping. That was about 5 years ago. I started using MMO in my gas about 3 years ago. Last year when I did a tune-up on my truck, I switched over to NGK plugs in the stock heat range. I changed to NGK because I had read some horror stories about Autolites being junk now that they are made in China. I was worried that the ping would come back since I was using the stock heat range plug again, but that was about 16 months ago and still the ping has not returned. I believe the MMO has kept my pistons and combustion chambers clean and stopped carbon from forming, so that is why I have no pinging now.

As far as adding the MMO to your oil I don't know how much oil a 4.7 calls for. When I ran MMO in my oil I always used just a pint. My 3.9 holds 4 quarts and I put in 3.5 quarts of oil and one pint of MMO, kept the half quart of oil and used it to top off the oil later on. In my truck I topped it off around 800 miles after that oil change. You can use the full quart, just don't exceed 20% of your total oil capacity. And be prepared to see the oil turn black quicker because MMO does do some good cleaning in the crank case. You may notice pretty quick with MMO in the oil that your truck starts easier and idles smoother and quieter. I know my truck just felt like it had more pep in her step when I had MMO in the oil, but that can happen any time the oil is thinner than usual. MMO is said to enhance the oil's lubricating properties and my truck ran very well with it.

One other thing is that MMO is not a magic-cure-all-in-a-bottle. Most everyone I know who has used it has had at least some good results from it, some more than others. Some say it did not do squat for them, but you find that much more often with newer cars and newer engines/fuel systems. I believe MMO provides much more benefits to older engines that can really benefit from the improved piston ring seal and increased compression that comes from the upper cylinder lube properties of using MMO in the gas. That is the most noticeable thing I see about it. I did some experiments last year without MMO in my fuel and there was a definite loss of power and idle quality without it.

You can find out more about MMO at their web site www.marvelmysteryoil.com. Check out the "ask the mechanics" forum for a lot of good posts and questions/answers. www.bobistheoilguy.com has a lot of MMO posts too, both in the oil additive and fuel additive forums. Some people there bash MMO because it has no scientific proof that it does anything, and other people post a lot trying to defend MMO too. I used to post about it a lot but got real tired of defending my MMO use. I am Jimmy9190 on the Bob is the Oil Guy site too. Here is just one MMO post you might read up on:

http://www.bobistheoilguy.com/forums...07#Post2656307

If you keep an open mind and try it for a long enough period of time you may find good benefits from MMO too. It sure won't hurt anything to try it out for a while.

Jimmy

 

mmo best thing it did for me was freeup some piston rings in my 2.5 engine. How popped off all my sparkplugs pored about 2 oz. in each cylinder turn the engin over by hand a few times to get it down the cylinders let soak for a few hours then repeat I did this about 5 times then let it sit over night.

Gained lost power with my 2.5 it worked great.

mmo good stuff

 

Again, thanks Jimmy.

I really think MMO could help with my winter driving conditions. My gas mileage drops like a rock in the winter. I can do 18mpg all day on the highway at 70mph in the summer and as soon as winter hits, I am lucky to see 15.5 - 16. I'm not sure exactly what is different about the gas in the winter but it sure makes a difference. That, and the fact it is blended with ethanol, makes for awful gas in my opinion.

Recently I've felt that my truck is a little more sluggish than it was a couple years ago. I doesn't feel like the power and throttle response is the same. This is understandable due to the fact it almost has 150k miles on it, but I would still like to see it come back. Perhaps with the use of a fuel system cleaner and the regular use of MMO, it will slowly come back. I don't except to add MMO and it turn into a rocket ship, but I would like to recover some of the power I feel like I've lost over the past year.

The 4.7 takes 6 quarts of oil and I feel like even 6 quarts is a little low. I changed the oil last weekend, filled it up with 6 quarts, and it was barely in the "safe" area of the dip stick. I've checked it a couple times and it seems to be consistent. Maybe I use 5.5 quarts of oil and 3/4 - 1 quart of MMO?

While we're on the topic of oil... Do you typical use conventional Q-State or the high mileage conventional version? Some people say that the high mileage oils are no good, others say they help... just wondering your opinion. I know your truck has similar miles to mine. I've been using Purolator filters, nice to see Wal-Mart sells them now. Hopefully they're the same Purolator filters that other auto parts stores sell and not a lesser quality filter just so Wal-Mart can sell it cheaper. I'm not sure if anyone knows the answer to that. They just stated selling them at my Wal-Mart.

No worries about the long posts Jimmy, I enjoy reading them.

 

Wow, 6 quarts, I had no idea a 4.7 had that big of a sump. I don't know about it reading low on the dipstick, maybe there is another half to 3/4 quart still in the filter when you check it? I like to check my oil when the engine is dead cold or my truck has not been driven for at least 3 or 4 hours. I think that gives the most accurate reading.

If it were me I would just do the 5 quarts of oil and only 1 quart of MMO. With that big of an oil capacity I would not overfill it, just so you don't worry about frothing and cavitation from the crank whipping up the higher level in the oil pan. It might be OK, maybe other 4.7 guys have overfilled with no problems but I have no idea on it. Whenever I have added MMO to my oil I always use only a pint of MMO and 3.5 quarts of oil, just because I have a lower oil capacity. Either way just keep a close eye on the level and add oil when you need to.

I use Quaker State conventional Advanced Durability 10W30. I don't really care much for the high mileage oils because they are blended at the thicker end of their given viscosity and the result is lower MPG. I ran Maxlife in my truck for a while and took a hit on MPG and power too. I switched back to regular oil and everything went back to normal. High Mileage oils do have their place though, if you have a problem with bad oil consumption or leaky gaskets or seals. I know some guys online who had Maxlife fix a leak problem right up in just one oil change. Over on Bob is the Oil Guy the new Quaker State Defy is getting some good reviews too. For now though I use plain conventional QS. QS is about the best oil I have used in my truck. I bought a couple of cases year before last when Advance had it on sale with Purolator Classic filters. Each quart and filter in my stash only cost me about $2.17 apiece. Not even Walmart can beat that price. The Puro filters at Walmart are the same as the ones at the parts store, as far as I know. The Mopar filter you can buy at Walmart or the Dodge dealer is also made by Purolator. Purolator is a great filter for a normal 3,000 mile oil change. I have been using them for years, never had a single problem with them.

As far as the power loss a good fuel system cleaner and MMO can possibly help out, but maybe check the O2's? If yours are original they could be getting lazy so your PCM might be leaning you out a bit or dumping more fuel in the mix depending on what the O2's are doing. Does a 4.7 have a MAP sensor? If it does maybe your MAP spec is on the low end of the acceptable range so the PCM retards the timing. I don't know about a 4.7 but I changed my own upstream O2's and my MAP sensor around about 80 or 85K and it helped a pretty good bit on power. It helped on MPG too. There is a thread on here some where called "MPG and Power Loss Solved" or something like that. That is where I learned about the MAP sensor. I think the MAP, O2's, keeping the fuel system clean and running good gas and the right oil and regular tune-ups with good quality parts are the most essential parts of getting good power and MPG. I change my PCV valve and air filter out on a regular basis too.

I hope the MMO works out well for you. My own theory is that it does work best in older engines. If you are a bit low in the oil sump, maybe remove the oil filter and drain it out, then add a pint or 3/4 quart of MMO and see how it runs after that. You can chcek for foaming and cavitation by running the engine for a few minutes and then pull the dip stick out right away after turning the engine off. If you see small bubbles on the stick, you have too much oil in the pan and the crankshaft is foaming it up. I was kind of skeptical when I added that first pint of MMO to my oil, had to kind of convince myself to do it, but man there was a real good difference in the way my engine ran and sounded after that. It felt like it was running "slicker" and a bit more loose and it ran really quiet. The difference in power was not huge but it was noticeable right away, at least in my case it was. 3.9 is not really known for having great gobs of power to begin with anyway.

Let us know how it turns out for you.

Jimmy

 

The 4.7 has a MAP sensor. It could be a portion of the loss of power. It doesn't feel like I've lost a ton of power or anything, but just doesn't quite feel like it used to. Again, this is probably just due to the miles. The O2's may be showing age and combined with the MAP sensor, may be sending some false information to the computer. Unfortunately, I just don't have anywhere to work on my truck. I'm planning on taking my vacation time in October and will probably make a trip to my parents. I can use their garage to go completely through the truck. I'm kind of gathering a list of things to do for then so I can get as much done as possible in one weekend. Good time to get it ready for winter.

So far I plan to:
Change the front diff fluid (rear was done when the pinion bearing was replaced)
Clean my air filter (k&n drop in)
Change the oil
Change the wipers
Clean the battery terminals good
Fix the lug nuts that have broken caps so I don't need to carry two different size sockets
Rotate the tires while I'm at it
Grease the ball joints

Those are the basics. How can I test my current O2's and MAP sensor?

 

Well you got me sold! Lol. I've got the typical 3.9 ping as well, sounds like a trip to the parts store and the garage for an injector clean. Thanks for the tips fellas...cheers!

 

@Bpark-to check the MAP sensor, you probe the center wire on its electrical connector plug. Turn on the ignition to "Run" but do not start the engine. The center wire should read somewhere between 4 to 5 volts. Then start the engine and let it idle for a few minutes. The voltage on the middle wire should slowly and steadily decrease to about 1.5 to a maximum of 2 volts. If it drops below 1.5 volts the sensor is bad. I replaced mine even though it was on the low end of the acceptable voltage, it read about 1.6 volts or something like that. I don't know if the MAP sensor is the same for a 4.7 as a 3.9 but I bought my new one at Auto Zone, it was $66.00. If you have an IAC valve, clean it too, when it and the throttle body get dirty it can make the truck run poorly. Usually you have problems with a bad idle or stalling when the IAC is gunked up. You can remove it and clean the pintle end with a shop rag soaked in TB cleaner. Be careful with it and don't drop it or you will need a new one.

I don't know of a DIY test for an O2 sensor. The voltage output on those fluctuates so much that you really need an oscilliscope to check them. Or the Dodge dealer can check them with the DRB scan tool, for a price. I wonder if some of the new OBD scanner tools can check an O2? Someone else here might know for sure. On mine I just replaced both upstream sensors as maintenance and it made a good improvement in how my truck ran.

I had the problem with the silver caps popping off of my lug nuts too. Every time I put an impact wrench to my wheels or a tire shop had to remove lug nuts I would always lose one or two of those caps. I was buying new ones at the Dodge dealer, but that got expensive, they cost 6 or 7 bucks each. The day I went and got my V8 TB cable at the you-pull-it yard I also found a Durango there with all of its lug nuts scattered on the floorboards. I filled both of my front pockets with lug nuts, probably 20 in all and the yard charged me 5 bucks for all of them. That was a fun trip to the yard, it was July or August, it was raining off and on, it was very hot, humid and muddy tromping around the yard, but I got what I needed at a good deal. I have not lost any lug nut covers in the last year or two now though.

Let us know how it turns out.

@BCDakota-I hope the MMO does as good a job for you as it does for me. Just remember, you have to use it for a while to really get any results from it, as far as the pinging goes.

Jimmy

 

Thanks for the tips on checking the MAP sensor. Pretty straight forward.

As for the O2's my father-in-law has an oscilloscope at his shop. He owns an electric motor & generator repair shop. One weekend when I'm over there I can go down and check it. I know he knows how check them with an oscilloscope so I'll have him show me. I forgot that's a way to check them.

Thanks for the 23rd time Jimmy haha! I love picking your brain on this stuff, you leave such detailed and professional posts and I appreciate it. I've learned a lot over the years on this forum, especially from you.