Technical issues were reported on 9 May
The Isle of Man Steam Packet Company says repairs to one of the Manannan's engines is complete and is now operating to schedule.
Just over a week ago, technical issues arose with the inner main engine on the starboard side.
Trips to and from Liverpool were subsequently extended as a result.
The company has thanked passengers for their patience.
Police 'respect' death by dangerous driving acquittal
Constabulary asks for privacy of family to be respected
Bank to withdraw three ATMs
There has been a series of ATMs withdrawn across the Island in recent years
Long closed pub could have a future
It was bought by government in 2007
'Tourist tax': Will the Island follow our neighbours in implementing levy?
England set to become latest place to impose a charge