looks like the exhaust pipe has been left open , so pretty sure that is an engine tear down job. the soaking thing only works on lightly stuck from condensation or a quick catch on it when rain has entered.
any tractor with the 282 engine. common problem on these engines. make sure the head and block is flat. plus do the job correctly, with a retorque and valve set after an hr or 2 of running. I have a 560 and the head has never been off, has 5600 hrs.