Two problems related to engine head gasket leaking have been reported for the 2003 Toyota Highlander. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 Toyota Highlander based on all problems reported for the 2003 Highlander.
The engine was pouring anti freeze on the road from the engine. The engine's head bolts were striped causing the head gasket to leak. This was a manufacturers defect and even sent out a service bulletin but should have been a recall due to the safety of other cars on the roadway. The epa should also be involved due to the hazardous material being placed in the ground.
2003 Highlander , 2. 4 engine started leaking antifreeze on driveway. Pressure tested ok. Head gasket leaking due to stripped head bolts. Mechanic stated this is a common problem with the 2. 4 engine. Usually between 80,000 & 120,000 miles. Repair estimated at $2000.