Two problems related to manifold/header/muffler/tail pipe have been reported for the 2004 Toyota Highlander. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Toyota Highlander based on all problems reported for the 2004 Highlander.
Engine was leaking coolant. Car was brought to repair shop where it was discovered that the engine cylinder's head bolts were stripped causing the leak. Later was informed damage was due to the placement of the insulation foam rubber piece between the intake manifold and the engine block that created an uneven dispersion of heat, creating fatigue in the aluminum block allowing the headbolt to strip. Contacted Toyota who refused to acknowledge manufacturing defect. Repairs totaled $2,000 due to this manufacturing error.
The contact owns a 2004 Toyota Highlander. While driving approximately 40 mph, the contact noticed that the check engine warning light illuminated. The vehicle was taken to an independent mechanic who informed the contact that the cylinder behind the intake manifold was leaking and that she would need to replace the engine. The dealer advised the contact that since the vehicle was no longer under warranty they would not be able to provide her with any assistance. The manufacturer was notified and the contact was waiting for a response. The vehicle was not repaired due to the cost. The current and failure mileage was approximately 78,000.