8.1L Chevy Workhorse Engine Issues

Thanks for all of the input. I did a search online and found that the water temp sensor could be loose. I crawled under and saw coolant on the exhaust manifold on the driver side. I tightened down the water temp sensor, 3/4 turn and I think I need to clean off the coolant from the exhaust manifold and crawl under while it is running and look for any spraying coolant. Please let me know if you have anything else that I should be checking and thanks.