Could a 98 Toyota Avalon XLS need the engine flushed at 105K miles if oil has been changed every 3K miles?

It is generally not necessary to flush the engine of a 1998 Toyota Avalon XLS at 105,000 miles if the oil has been changed every 3,000 miles. Flushing the engine involves using a chemical solvent to remove built-up sludge and deposits, but if the oil has been changed regularly, there should not be a significant amount of build-up that requires flushing.

Regular oil changes help to keep the engine clean and lubricated, removing contaminants and preventing the formation of sludge. If you have concerns about the cleanliness of your engine, you can consult with a trusted mechanic or refer to the owner's manual for recommended maintenance procedures. They may recommend inspecting the engine oil and conducting any necessary maintenance based on the vehicle's condition and driving history.