Salvors hope to start pumping lubricant and hydraulic oils from the engine of the stricken Rena today, but it is not yet known how much remains on the ship.
Hundreds of tonnes of oil have been pumped off the Rena and onto the Awanuia since the container vessel grounded on the Astrolabe Reef near Tauranga on October 5.
However, about 358 tonnes of fuel oil remains in the Rena's submerged starboard five tank, while an unknown amount of engine oil remains the engine room.
Maritime New Zealand salvage unit manager Bruce Anderson this morning said said a team of three salvors had remained on Rena overnight to pump lube and hydraulic oils in the engine room into a centralised tank.
Salvors hoped to begin pumping engine oils onto Awanuia by the end of the day.
A Maritime New Zealand spokesman this morning said it would not be known how much engine oil was on board the ship until later today.
Plans to remove the fuel oil from the starboard tank were also progressing.
Divers yesterday continued work to re-establish a dive station, while work was also progressing on a "hot tapping'' technique to transfer the oil from the starboard tank.
Hot tapping involves penetrating an oil tank underwater in a way that does not release oil into the environment.
Meanwhile, a team of 25 volunteers and local iwi have spent the last five days cleaning oil from the rocky foreshore on the northwest and northeast of Motiti Island.
Operation Beach Clean manager said there had been enough volunteers willing to spend up to a week on the island to rotate teams if needed over the next couple of weeks.
The volunteers have been joined by Australian rock clean-up specialist Peter Braddock, who had provided advice on cleaning oil from the rock pools.
"The focus of the clean-up is on oil that is easily collected from the rocky shoreline,'' Mr De Monchy said.
"We are fortunate in a sense that Motiti Island has a coastline with rough seas. This actually helps with the removal or degradation of the oil.''
Large quantities of timber and various other pieces of container debris have also washed up on the island, with specialist container removal company Braemar Howells working to remove the debris.
