One Nation leader Pauline Hanson's Battler Bus has broken down on its way north to Mackay.

The bus began making a loud hissing noise near Marlborough and was parked at a local petrol station awaiting a mechanic on Thursday morning.

One Nation leader Pauline Hanson is seen inspecting the engine bay of the Battler Bus. Credit:AAP

The federal senator boarded the bus in Rockhampton on the fourth day of her tour of key seats in central and northern Queensland ahead of the November 25 poll.

Ms Hanson started the morning when she refused a halal-friendly McDonald's breakfast on the Queensland election trail, instead taking up a fish and chip shop owner's offer of instant coffee.