good or bad

 

cant really tell,is that back driverside plugged completely?

 

Typical build-up and deposits , but would seem to indicate more frequent oil changes should be done , also the water passages ... plain water for coolant or weak antifreeze for an extended period . I've always run a number of short OCI using the good engine cleaning ability of mobile one synthetic oil along with new oil filters to bring back neglected engines with excellent results - never liked the idea of putting solvents in the engine oil ... now I use Napa full synthetic oil since I got a truck load of it on sale recently good stuff made by valvoline I believe .