I have a 04 accord V6 - I’ve religiously done oil changes with synthetic high mileage every 5000 miles, and it’s coming up to 215k miles. Engine runs fine. I was thinking of adding a bit a Seafoam high mileage to engine oil before upcoming oil change to help clean out gunk for general maintenance - I always put Seafoam in the fuel tank every 5k miles to clean out fuel system but never did it in crankcase. However, seeing as how I have never done it in the oil, and always did good oil changes, a buddy said better maybe not add it as I don’t have engine issues and it may knock stuff loose after 215k miles that’s better to just leave in place… thoughts? Better to add it or just leave it be in the engine oil? Thanks

 

I would argue Seafoam is a complete waste of money, regardless of whether you put it in your gas tank, your crank case, or use it to polish your paint and wheels.

 

"I would argue Seafoam is a complete waste of money, regardless of whether you put it in your gas tank, your crank case, or use it to polish your paint and wheels."
+1.
No flush or additives are necessary. Just change oil every 5k miles. avoid the snake oils.