Bad gas, rough idle?

[Jimmy9190]

I posted this here in the fuel adds section because it really has more to do with fuel and MMO than it is a mechanical problem. A few months ago I started working from home, so now I don't drive my truck nearly as much as I used to now. Maybe every other day I will drive to the grocery store a mile away or out to eat, movies etc which are all within 5 or 6 miles from home.

I have been using MMO in my gas for amost two years now but I bought gas a few days ago and did not add any MMO. I wanted to see how my truck ran without it. It was not good, the idle was noticeably more rough, not nearly as smooth and my truck seemed a bit sluggish, like it had less power. The gas was from the local Marathon station. I have had no problems with Marathon up until this point.

I did make a few short trips last week and yesterday took about a 50 mile round trip to Orlando and back. I did not like the way my truck was running so today I added about 3/4 pint of MMO to my oil and 6 ounces MMO to the gas tank.

I drove today about 10 miles and already the truck runs smoother like it always has with MMO and seems to have more power. In other words, it runs like it did before I skipped the MMO last week.

Just wondering if anyone else sees a rough idle from a vehicle that does not get driven very often or very far? If so what has anyone done to alleviate it? Anyone else have any noticeable differences without MMO as opposed to with it?

Please don't turn this into an MMO bashing post. I just want to see if any of us here has had a similar experirnce.

 

[WMSmotorhead]

I used MMO regularly for awhile... and didn't see a huge result. But no harm. I've not used it in a year or so. Any time a motor isn't smooth at idle, I taka the time to clean the Air Intake. I suggest a cleaner that's safe to "let the motor suck in". Berryman B-12 Throttle Body, and my fav, Justice Bros. are in an easy to use spray can. Others like Sea Foam... Air intake dirt/clogs, PCV or Emmssion reciculation stuff will muff up your idle if it's dirty. Cleaning the intake and MAF sensor may solve the problem.

A good intake cleaning always gave me a bump in MPG, back to where it "should be"...

 

[Oregoonian]

Fuel Filter.... been changed lately?

 

[Jimmy9190]

Fuel filter is part of the fuel pump assembly. I changed the whole assembly out last year. I believe the difference is due to the improved compression and better ring seal from MMO helps my truck run better.

 

[Jimmy9190]

I drove my truck again today, it seems to be back to its old self again. It has better power, more get up and go on the butt dyno and my engine is back running smooth again too.

Yesterday when I added the MMO to the gas I did that here at home, I had a little more than half a tank when I added it. I drove less than a mile to 7-11 and topped off with about 8 gallons of gas. I think I may have gotten some bad gas at Marathon last week and the 7-11 gas has helped to dilute it out. Or maybe my truck just had some very noticeable differences without MMO, since I have been using it for a long time.

I went back and checked my gas purchases on my fuelly.com page and it looks like about 75 or 80% of the time I was getting a little better gas mileage on 7-11 gas. My truck seems to run a little peppier on the 7-11 gas too. I had not been using Marathon that long but wanted to try it out and see how it did.

Even though I would like to continue to support Marathon because they are an American fuel company and I read that they do not use any Middle Eastern or South American oil, I believe I will just stick to 7-11 gas now. Of all the gas I have tried I seem to get the better MPG on 7-11. I have read that 7-11 has its own proprietary blend of gas and additives and that they do not use Middle Eastern oil either.

If I go on a trip where there is no 7-11, I guess I'll look for a Quik Trip or Chevron. 7-11 is everywhere around here where I live. And I won't forget or skip the MMO dose again either. My truck is getting up there in age and MMO does help it run better. I may even start adding a pint of MMO to my oil every 1500 miles again. The stuff works and in my case anyway it works very well.

 

[CROWNVIC4LIFE]

Originally Posted By: Jimmy9190

I have been using MMO in my gas for amost two years now but I bought gas a few days ago and did not add any MMO. I wanted to see how my truck ran without it. It was not good, the idle was noticeably more rough, not nearly as smooth and my truck seemed a bit sluggish, like it had less power. The gas was from the local Marathon station. I have had no problems with Marathon up until this point.

Just wondering if anyone else sees a rough idle from a vehicle that does not get driven very often or very far? If so what has anyone done to alleviate it? Anyone else have any noticeable differences without MMO as opposed to with it?



About 2 weeks ago I drove my moms 2005 4.6 Vic [which does a ton of short trips] and noticed it was real sluggish and idling rough..She uses Marathon gas..I took it on a run then filled it up with Mobil gas..The car runs amazingly smooth again.

I do not want to make the bottom line for Exxon-Mobil any higher then it already is but in my neck of the woods the Mobil stations are very well maintained plus they have the lowest prices..Marathon and Mobil are the same price where I live..My sister used to get Chevron gas [which is always at least 7 cents higher then anyone else down here] and now uses Mobil and she says her 4.6 [07] GMQ runs alot smoother.

I have never used MMO but I know one person who uses it in his 2009 P71 and loves it.

 

[Jimmy9190]

Yeah I think I will stay away from Marathon. Maybe it's their STP additives or some other problem but it just didn't work for me. My truck is back to its normal self now but I am just going to run this current tank down as far as I safely can and refill it with 7-11 gas, and continue on using MMO in my gas like always. Thanks for the reply.

 

[moto94536]

I never use additives. My camry is 220,000 miles, and keep going. what is the secret? I use top tier gas from chevron..

Don't waste your money on additives, and start using top tier gas.