I just got my Marvel's today and added 16oz to my oil. The 4.0 sounds better already. My question is: The label says to add to gas as well. Is this a good Idea and how much to add? 1990 Cherokee Limited 303k miles.

 

Run what it says on can...4 oz for every 10 gal gas....so 6-8 for a fill up

 

Homestd, have you looked through the oil filler hole to see how much sludge you have, if any?

 

Cruiser, I did the valve cover gasket a while back, and I was surprised that the top end looked pretty good, better than my 88 with 75k more miles. I did pull the crankcase vents out the 88, as you suggested, and they have the 1/2" hole already. They're soaking at the moment. That stuff is nasty.

PS: It still has a miss, but I'm going to "drive it like I stole it"! I'm working on my first hundred miles in it.

 

The MMO will melt that sludge.

 

I've run MMO in my '88 since I got it 20 years ago. No sign of any sludge when I did my VC and RMS.

I don't typically run it in the fuel. About once year (and always before smog testing), I run a can (or two) of Seafoam in the tank and down the intake.

 

MMO is amazing.
For fuel system and combustion area/valve cleaning, nothing beats BG 44K.
Add a can to a full fuel tank. Run the tank down to half. Then fill the tank and run to about a quarter tank.

 

hi
turkish citizenship
Cruiser, I replaced the valve cover gasket a while back and was pleasantly impressed by how wonderful the top end looked, even better than my 88 with 75k more miles. As you indicated, I removed the crankcase vents from the 88, and they already had the 1/2" hole. They're now soaking. That's really awful thing.