2003 Toyota Highlander Problems
RepairPal has identified the most common problems with the 2003 Toyota Highlander based on complaints from actual vehicle owners. We'll tell you what the problem is and what it'll take to fix it.
The head gasket may fail due to a defect in manufacturing of the cylinder block.
On this vehicle, the head bolts are known to pull the threads out of the engine block, allowing the head to slightly lift, and causing head gasket failure. Symptoms may include:
- White smoke from exhaust
- Rough running conditions and/or inability to start or idle
- White or cream colored oil on dipstick
- Check engine light
- OBD Trouble Codes P2181, P0300
When the head gasket fails, the bolt holes for the head bolts must be repaired before the cylinder head can be remounted.
This issue is not always preventable, but to help avoid it, never run the engine if the engine temperature is ever above the normal range.
A problematic center airbag sensor can cause the airbag malfunction light to illuminate.
Debris can get into the idle air control valve. This will restrict the air flow into the engine, causing idle speed and/or stalling when cold. The valve can be cleaned or replaced to correct this concern.
Sludge can build up in the engine because Toyota did not recommend frequent enough oil changes. Lexus will sometimes offer a discount on cleaning the engine if necessary. Owners who changed their oil every 3,000 miles did not experience these problems. This sludge build up can lead to excessive oil consumption.
The 2001-2003 Toyota Highlander with the 3.0L V6 engine has a known issue with the valves that if left unchecked, will cause burned valves and engine performance issues.
The engine ‘breathes’ through valves that are pushed open by the camshaft, and closed by springs. When valves are closed, they seal against a valve seat. In this vehicle, the valve seat is too soft, so after the valve contacts it thousands of times, it becomes crushed. Once it is crushed, the valve can no longer make a proper seal, and the valves erode due to extreme temperature (burnt valve).
Symptoms related to this issue:
- Rough idle
- Backfiring through exhaust or intake
- Illumination of the check engine light
- OBD Trouble Codes P0300, P0301, P0302, P0303, P0304
- Loss of power
- Engine Stalling
To repair the burnt valves, the cylinder head must be removed and rebuilt, which is a costly internal engine repair, however, this issue can be prevented through inspection and adjustment of valve clearances every 40,000 miles.