# Marvel Mystery Oil in Fuel

**URL:** <https://community.cartalk.com/t/marvel-mystery-oil-in-fuel/50736>\
**Category:** Maintenance/Repairs\
**Tags:** damage, engines, toyota, camry, oil\
**Created:** [June 23, 2010, 2:20am UTC](https://community.cartalk.com/t/marvel-mystery-oil-in-fuel/50736 "2010-06-23T02:20:45Z")\
**Posts on this page:** 10\
**Page:** 1

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**Author:** ![Techniker](https://avatars.discourse-cdn.com/v4/letter/t/bcef8e/32.png) [@Techniker](https://community.cartalk.com/u/Techniker)\
**Post date:** [June 23, 2010, 2:20am UTC](https://community.cartalk.com/t/marvel-mystery-oil-in-fuel/50736/1 "2010-06-23T02:20:45Z")

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So I generally add MMO in the recommended quantity (maybe a bit more if I haven’t used it in a while) to my gasoline. I like to think that it serves some purpose as a top lubricant even if it probably doesn’t make any difference.  
  
  
  
 I drove the car for a while (about 100 miles) and parked it at my house. Since I am the one who always drives around, I used my wife’s car so some of the wear could be shared on her vehicle (I am a poor engineering/medical student). I let the car sit for about three days. When I started it up, it took a little bit longer for the engine to catch as expected but then I heard a metal clank sound. It sounded exactly what you would expect to hear when a car drives over a sewer cover. I couldn’t tell if it came from my car or if someone actually did just run over a sewer cover behind me (my wife was on one of her talking sprees where you can’t even process the information as fast as she can ramble and so I am really not sure).  
  
  
  
 Now, assuming it was my car, what do you think that sound would be coming from? Do you think the Marvel Mystery Oil could have caused an autoignition (I have heard an autoignition before but it didn’t sound like it- autoignition tends to have a more dieseling kind of sound).  
  
  
  
 Thank you in advance,  
  
 Techniker

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**Author:** ![MG-McAnick](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mg-mcanick/32/188_2.png) [@MG-McAnick](https://community.cartalk.com/u/MG-McAnick)\
**Post date:** [June 23, 2010, 3:01am UTC](https://community.cartalk.com/t/marvel-mystery-oil-in-fuel/50736/2 "2010-06-23T03:01:21Z")

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I suspect the sound was the starter re-engaging the flywheel as it was still turning. I’ll be surprised if it does it on a regular basis.

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**Author:** ![Goldwing](https://avatars.discourse-cdn.com/v4/letter/g/e68b1a/32.png) [@Goldwing](https://community.cartalk.com/u/Goldwing)\
**Post date:** [June 23, 2010, 3:28am UTC](https://community.cartalk.com/t/marvel-mystery-oil-in-fuel/50736/3 "2010-06-23T03:28:14Z")

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Save your money for tuition, you’re probably wasting money putting it into your gas tank.

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**Author:** ![Techniker](https://avatars.discourse-cdn.com/v4/letter/t/bcef8e/32.png) [@Techniker](https://community.cartalk.com/u/Techniker)\
**Post date:** [June 23, 2010, 5:09am UTC](https://community.cartalk.com/t/marvel-mystery-oil-in-fuel/50736/4 "2010-06-23T05:09:11Z")

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That was my bet too, I was hoping someone else was thinking the same thing. Now I can rest with ease and know it wasn’t just my own wishful thinking. Thank you.

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**Author:** ![Techniker](https://avatars.discourse-cdn.com/v4/letter/t/bcef8e/32.png) [@Techniker](https://community.cartalk.com/u/Techniker)\
**Post date:** [June 23, 2010, 5:09am UTC](https://community.cartalk.com/t/marvel-mystery-oil-in-fuel/50736/5 "2010-06-23T05:09:58Z")

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If it saves my engine a bit of wear and maybe even prolongs the life of my fuel injectors just a little, it’s worth it. Besides, even a placebo is worth it to me, MMO is dirt cheap as it is.

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**Author:** ![Caddyman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/caddyman/32/23_2.png) [@Caddyman](https://community.cartalk.com/u/Caddyman)\
**Post date:** [June 23, 2010, 5:10am UTC](https://community.cartalk.com/t/marvel-mystery-oil-in-fuel/50736/6 "2010-06-23T05:10:17Z")

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Whatever made the “clank” it was not the Marvel Oil…Whether adding top oil to the gas offers any real benefit is a debate that has been going on for 90 years…it certainly does not hurt anything…

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**Author:** ![ZombieWoof](https://avatars.discourse-cdn.com/v4/letter/z/91b2a8/32.png) [@ZombieWoof](https://community.cartalk.com/u/ZombieWoof)\
**Post date:** [June 23, 2010, 7:38am UTC](https://community.cartalk.com/t/marvel-mystery-oil-in-fuel/50736/7 "2010-06-23T07:38:17Z")

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What happened when you immediately shut the car down and restarted it? Did you hear the sound on the second trial? You didn’t mention that in your post.

Engineering? Medical? Okay…

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**Author:** ![Techniker](https://avatars.discourse-cdn.com/v4/letter/t/bcef8e/32.png) [@Techniker](https://community.cartalk.com/u/Techniker)\
**Post date:** [June 23, 2010, 11:31am UTC](https://community.cartalk.com/t/marvel-mystery-oil-in-fuel/50736/8 "2010-06-23T11:31:53Z")

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Undergraduate: Chemical/Pharmaceutical Engineering  
Currently: Medical School

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<div class="post-metadata">

**Author:** ![Techniker](https://avatars.discourse-cdn.com/v4/letter/t/bcef8e/32.png) [@Techniker](https://community.cartalk.com/u/Techniker)\
**Post date:** [June 23, 2010, 11:39am UTC](https://community.cartalk.com/t/marvel-mystery-oil-in-fuel/50736/9 "2010-06-23T11:39:15Z")

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Glad to hear it. I thought it might be partially responsible for the atypical hard start. The issue has not resurfaced.

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**Author:** ![geeaea](https://avatars.discourse-cdn.com/v4/letter/g/6f9a4e/32.png) [@geeaea](https://community.cartalk.com/u/geeaea)\
**Post date:** [June 23, 2010, 11:39am UTC](https://community.cartalk.com/t/marvel-mystery-oil-in-fuel/50736/10 "2010-06-23T11:39:32Z")

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Did it happen only once?

MMO didn’t cause it. Continue using as recommended (dosage rate) if you so desire.

Using too much too (as in WAY TOO MUCH) often will soot up your plugs. The recommended dosages should be fine.
