1999 Toyota Sienna Problems
RepairPal has identified the most common problems with the 1999 Toyota Sienna based on complaints from actual vehicle owners. We'll tell you what the problem is and what it'll take to fix it.
Models with electric sliding doors can develop problems with the door mechanism. The cable in the door becomes frayed, which will damage the electric motor.
The 1998-2003 Toyota Sienna 3.0L V6 may start and stall, or start and run at very low engine speeds when the engine is cold.
The issue is a failed or dirty idle air control valve. This valve is mounted under the throttle body, and modulates airflow to the engine under certain conditions. When the valve becomes dirty, or when the valve fails, proper airflow to the engine is not achieved. This results in start and stall, and low RPM.
To correct the issues, the idle air control valve will need to be tested, and cleaned or replaced.
To help decrease the frequency of this issue, change the air filter no less than once per year.
Multiple cracks may develop on the upper surface of the dashboard. At this time, the only suggested repair is to replace the dashboard.
The 3.0L V6 engine used in the 1998-2003 Toyota Sienna 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.
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.