The head gasket issue was solved years ago from what I understand.
The notorious head gasket issue that plagued Toyota's 3.0L V6 was solved years ago as the motor became obsolete and was replaced by the 3.4L motor, and then later, the 4.0L motor. Toyota conducted a "special service campaign" to address the 3.0L head gasket failures.
The 4.0L V6 (1GR-FE) was first used in the 4Runner in the 2003 model year (4th Generation 4Runner). Based upon my mechanic's experience, my limited Internet research and the ongoing experience with my own 2006 4Runner, head gasket failure seems to be becoming a more prevalent issue as these 4.0L motors begin to age and rack up miles in excess of 100k.
All of the links that I posted above relate to head gasket problems that have occured with 4.0L motors within the last few years or months. Anyone considering buying a used 4Runner with the 4.0L motor might be well served to consider the potential costs of replacing a head gasket.
