I agree with making sure you dont have a contamination source of coolant or PS fluid before proceeding to far. Once you have ruled that out, or fixed that issue. this is how I would go about "flushing" the crankcase, I dont like seafoam or other
Get a change worth of cheap on sale oil. 1 qt of decent ATF. A change worth of your prefered oil load. and 2 filters
1 Drive around get things warmed up add 1/4 to 1/2 of tha quart of ATF and drive around for a while longer and then let idle and run for a 10 to 15 min longer after you get back to the barn. Drain oil, and change filter with the cheap oil, go for a drive, a longer one about an hour or longer. Come back to barn drain oil and change it and the filter to your preferred loading. ( I like Mobil Delvac 1 myself). Then Keep an eye on the color and whats going on, with in the system, and keep it on a short change cycle (3000k miles or less) until the issues are flushed. I would also use the CJ-4 Diesel oils as they are much better and picking up and moving crud to your filters and cleaning things. Also I found my 1FZ is MUCH happier with a 40w running weight oil than 30w variants, plus I only have to keep 1 oil on the shelf for my Duaramax and My 80