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Front main seal thanks to MMO

bluXkid

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So I was due an oil change like a week ago. Of course I run OEM filter and Mobile 1 advanced full synthetic 5w-30. Drained oil for about 45min then added my 5qts. I knew I was lacking .5 qts roughly so this past Sunday I added .5qt of MMO thinking it couldn't hurt, being that it's at 120k miles. Well I thought all was good until today I noticed some splatter on the LCA. I get under the truck and oil is splattered under the front of the truck. Looks like it's coming from crankshaft main seal. But I'm worried it's the pan.
Anyways, is this normal after adding MMO? And how much should I expect to pay for this repair?
 

Torspd

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What is MMO? Marvel Mystery Oil?

Very likely just the age of your seal.
 

Coupe

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The front seal is pretty to change. The hardest part is breaking loose the bolt on the crankshaft pulley.

I don't think the MMO caused your problem.
 

Gadget

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Oil leaks can be good or bad.....

On the older radial aircraft engines, if they are not leaking oil everyone freaks out and needs to figure out why, like maybe none left....

Anyway, if the main seal is leaking it will likely sling oil of the back side of the pulley. If it is not doing that it might not be the main seal.

I had a bad oil leak on my X a few years ago. It was from the front of the engine. Thought it was the main so I got a new one and pulled the pulley off and found a bolt behind the pulley had fallen out.
 
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