Never had a problem with this vehicle until Jan 25 2011 as I was driving across town. Coolant leak brought me to a dead stop. I discovered a common problem with this engine (2.4L 4cyl). Just Google Highlander stripped head-bolts to see how many of these engines are dying and how expensive the fix is. Mine had only 126,000 miles on it. I am the original owner. The dealer will not help with repair costs even though this is a manufacturing and or design issue.