Toyota 4Runner defective head gasket issue common in 4.0L V6 1GR-FE motor on Toyota 4Runner

Some Toyota 4Runner owners report experiencing issues with defective head gaskets in the 4.0-liter V6 1GR-FE engine, particularly in earlier 4th generation models. This problem has been noted in owner forums and Consumer Reports, indicating that a significant number of these vehicles suffered from premature head gasket failure. Although there is no definitive evidence of widespread failure across different Toyota models using the 1GR-FE engine, the issue has been acknowledged by Toyota, which introduced an updated part in mid-2005 to address it. Despite this, some owners continue to encounter head gasket failures, resulting in repair costs ranging from $4,000 to $5,000. Owners are advised to remain vigilant regarding potential head gasket issues and other common concerns such as ignition coils and water pumps in the 1GR-FE engine. If a head gasket problem arises, the average replacement cost for a Toyota 4Runner is estimated to be between $2,505 and $2,933.