After completing a timing belt and water pump job on a Lexus LS400, the owner has a coolant leak with unknown source, low idle, and weak heat at idle, needing help diagnosing the exact leak point befo

After completing a timing belt and water pump job on a Lexus LS400, the owner has a coolant leak with unknown source, low idle, and weak heat at idle, needing help diagnosing the exact leak point before disassembling again.