Shane van Gisbergen's TEKNO Autosports team is working to solve a vibration that has plagued his STIX Darrell Lea Commodore during practice at the Castrol EDGE Townsville 400.
Van Gisbergen set the fourth quickest time in the day's first session, only running warm up hard tyres, before settling in the garage.
His chassis, dubbed 'Lola' was new for the last round in Darwin, and ran without issues there and during its shakedown.
Today, however, he is unsure how he will be affected as his team now changes the transaxle between practice two and three.
"It's just got a big vibration, so feeling a bit sick from it even though I've only done two laps - they're trying to fix it," van Gisbergen told v8supercars.com.au.
"You can't be certain [of the problem] until we switch [the transaxle] - they tried to realign it and a few other things. They're just working through it."
The Kiwi hasn't had the chance to set a flying lap, so he was unsure whether missing the majority of the two sessions would be a big setback.
"I don't know - we'll find out when we get going," he said.
Van Gisbergen is characteristically quick at street circuits, though he has not won in Townsville yet. He has finished on the podium though, and is only one of eight drivers to do so. The 26-year old sits fifth in the Championship standings.
A third 30-minute session remains this afternoon, beginning at 12.45pm local time.
Erebus' Will Davison topped the second session, with Pepsi Max's Mark Winterbottom quickest in the first.