We have an LG dishwasher that sat in storage brand new unboxed for 10 years, until we moved and installed it in the new house. Well, it's making an awful grinding noise only during the first 20 minutes of pre-wash, after which it goes away and washes the dishes perfectly. When I open the door in pre-wash there's barely any water dripping down. What's it doing so different in pre-wash? My guess is the food disposer is running. Is this dishwasher past its lifespan or saveable?
Edit: Model is LDF6920ST