I popped open my valve cover and saw this peanut butter looking substance inside. I'm thinking it may just be spoiled grease that I use to seal the valve cover to the head. Any ideas?
The only thing that's changed is that I started using Marvel Mystery Oil this past year. Maybe it's how it interacted with the grease?
BTW - I'm definitely a believer in Marvel. Cold compression test before: 160/150/150/165. Cold Compression test after: 160/170/160/180. Might also have something to do with me getting better at making my valve adjustments.
The only thing that's changed is that I started using Marvel Mystery Oil this past year. Maybe it's how it interacted with the grease?
BTW - I'm definitely a believer in Marvel. Cold compression test before: 160/150/150/165. Cold Compression test after: 160/170/160/180. Might also have something to do with me getting better at making my valve adjustments.