90,000miles
No, changing the timing belt on a Toyota Highlander 4 cylinder is not difficult. You will need to remove the skid plate from under the vehicle to access the belt more easily.
Factory recommendation is 90,000 miles. If it is a timing CHAIN and not a belt, it doesn't require changing. It should last the life of the engine.
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
2002-2006 model year highlander's use a timing chain and do not be used
The 3.3 litre V6 engine in a 2005 Toyota Highlander has a timing BELT
The 3.3 liter V6 engine in a 2006 Toyota Highlander has a timing BELT
I have a 2006 Toyota highlander hybrid, do I need to change timing belt or chain?
You dont have it has a timing chain
I don't believe the 4 cylinder has a timing belt, but it does have a timing chain, which should be good for the life of the engine.Added: Info below is taken from the official Toyota website under FAQ'sHighlander2001-2007 4 Cylinder Chain2001-2007 V6 Belt2008 V6 Chain
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
Timing belt