Although E85 is an awesome fuel, high octane, cheap, cool burning, it can cause a lot of harm under certain operating conditions. This is an EJ257 that failed in my daughter’s car. When she was in high school, she only drove about 1.2 miles to her school from a cold start and after the car sat all day, then she drove the same distance home. Because of the short drive cycle, the engine never really got warm. I knew that E85 makes a lot more moisture than gasoline and was concerned about oil contamination from the mixture of blowby, E85, and water and had upped the oil change intervals to every 2000 miles with high-quality synthetic. Suddenly the car developed a lot of blowby and a loss of compression, I assumed it was a typical blown Subaru engine and yanked it out and it sat in the corner for a few years. Last week we decided to take the engine apart to see if it was any good to use as a core engine and we were amazed at what we found!
First off the pan was filled with a black tarry sludge, the kind you find in neglected engines, not ones that had the oil changed this frequently. The moist running E85 had created a ton of milkshake in the oil and with a big radiator and oil cooler, the engine never got hot enough to boil the water off so it coalesced into the sludge after time.
The underside of the cases had some varnish but it was not too bad, this shows that the oil was changed. The top end of the engine looked like new with no varnish or anything.