That would depend on the engine choice of the 2007 Highlander. The 4 cylinder model has a maintenance-free timing chain while the V6 model has a timing belt. The redesigned 2008s all have a timing chain however.
The 3.3 liter V6 in a 2007 Toyota Highlander has a timing BELT
In a 2004 Toyota Highlander : The 2.4 liter four cylinder has a timing CHAIN and the 3.3 liter V6 has a timing BELT
Timing belt
In 2008 the Toyota Highlander V-6 engine was equipped with a timing CHAIN.
if its petrol it should have a chain if diesel will hav timing belt
Belt
2002-2006 model year highlander's use a timing chain and do not be used
In a 2004 Toyota Highlander : The 2.4 liter four cylinder engine has a timing CHAIN The 3.3 liter V6 engine has a timing BELT
The 3.3 litre V6 engine in a 2005 Toyota Highlander has a timing BELT
I have a 2006 Toyota highlander hybrid, do I need to change timing belt or chain?
The 3.3 liter V6 engine in a 2006 Toyota Highlander has a timing BELT
The 2007 Toyota Highlander Hybrid is equipped with a timing chain rather than a timing belt. Timing chains are generally more durable and typically require less maintenance than timing belts. It's important to follow the manufacturer's recommendations for maintenance to ensure the longevity of the engine components.