2008-2015 Scion xB Engine Cooling Fan: Diagnosis, Replacement, and Costs

Symptoms of a Failing 2008-2015 Scion xB Cooling Fan

A bad cooling fan assembly will make itself known quickly, especially in warm weather or stop-and-go driving. Watch for these common signs of failure:

• Engine Overheating at Idle or Low Speeds: This is the most common symptom. When the car is moving slowly, it relies entirely on the fans to pull air through the radiator. If they fail, the temperature gauge will climb. The temperature may return to normal at highway speeds when natural airflow takes over.
• A/C Blows Warm Air: The cooling fans also pull air across the A/C condenser. If the fans aren't working, the A/C system can't get rid of heat effectively, resulting in warm air from the vents, especially when the car isn't moving.
• Fans Don't Turn On: After the engine has warmed up, or when you turn on the A/C, you should be able to hear the fans running. If you pop the hood and see that the fans are not spinning, it points to a problem in the system.
• Loud or Grinding Noises: A worn-out fan motor bearing can produce a loud grinding or whirring sound when the fan is active. You might also hear a rattling noise if a fan blade is broken and hitting the shroud.
• Warning Lights: A severe overheating event will trigger the engine temperature warning light on your dashboard. In some cases, a fault in the fan control circuit can also illuminate the Check Engine Light.

Diagnosing a Faulty Cooling Fan

Before replacing the entire assembly, follow these steps to pinpoint the problem. A failed fan motor is common, but the issue could be as simple as a blown fuse.

1. Check the Fuses: The first and easiest check is the fuses. In the under-hood fuse box, inspect the fuses labeled "RDI" and "CDS". If a fuse is blown, replace it. If it blows again, there is an underlying short circuit in the wiring or one of the fan motors.
2. Check the Relays: The fan motors are controlled by relays, which are small electromagnetic switches. A faulty relay will prevent power from reaching the fans. You can test a relay by swapping it with an identical one from a non-critical system (like the horn) to see if the fans start working.
3. Test the Fan Motors Directly: This test bypasses the rest of the car's wiring to see if the motors themselves have failed. Safely disconnect the electrical connector going to the fan assembly. Using jumper wires, carefully apply 12V power from the car's battery directly to the pins on the fan motor's connector. Be extremely careful to keep hands and tools away from the fan blades. If the fan spins, the motor is good and the problem lies elsewhere in the circuit (like the wiring or temperature sensor). If it does not spin, the motor is dead.
4. Check the Coolant Temperature Sensor: The fan's operation is triggered by the coolant temperature sensor. If this sensor fails, it may not send the correct signal to the ECM to turn the fans on. A common diagnostic trick is to unplug the sensor with the engine running; on many vehicles, this will force the fans to run as a fail-safe.

Buying a Used 2008-2015 Scion xB Cooling Fan Assembly

A recycled OEM fan assembly can be a smart purchase, offering original factory quality for less than a new part. However, it's important to inspect a used part carefully before buying.

• Check for Physical Damage: Inspect the entire plastic shroud for cracks, especially around the mounting points. Brittle, cracked plastic is a sign of age and heat exposure. Ensure all fan blades are intact, with no chips or cracks.
• Spin the Blades by Hand: With the assembly unplugged, spin each fan blade by hand (when safe to do so). They should spin freely with minimal resistance and no grinding or scraping sounds. A fan that is difficult to turn has a seized or failing motor.
• Inspect the Electrical Connectors: Look at the electrical plugs and wiring. Avoid any assembly with melted plastic, corroded pins, or frayed wires, as these indicate electrical problems or overheating.
• Verify Compatibility: While some early data suggested a mid-year change in 2008, extensive parts catalog information confirms that the same cooling fan assembly, OEM part number 16711-28400, fits all 2008, 2009, 2010, 2011, 2012, 2013, 2014, and 2015 Scion xB models.
• Why Used OEM vs. New Aftermarket: An original Scion/Toyota fan assembly was designed for a perfect fit and specific airflow characteristics. While quality aftermarket parts exist, some cheaper options may use lower-grade motors that can fail prematurely or have blades that don't move as much air, potentially reducing cooling efficiency. A low-mileage used OEM part is often a more reliable choice than a new, non-brand-name aftermarket part.

Replacement Overview (DIY Difficulty: 3/5)

Replacing the fan assembly is manageable for a DIYer with basic tools, but can be time-consuming. While some guides show the part being removed from the top, the official and easiest method for access often involves removing the front bumper cover.

The basic steps are as follows:

1. Disconnect the negative battery terminal.
2. (Recommended for easier access) Remove the front bumper cover, which involves several clips and 10mm bolts in the wheel wells and under the hood.
3. Remove the plastic radiator support cover.
4. Disconnect the electrical connectors for both fans.
5. Disconnect the upper radiator hose and the overflow tube. Be prepared for some coolant spillage; using a hose pinch-off clamp can minimize the mess.
6. Unbolt the fan shroud from the radiator (typically two bolts at the top and clips at the bottom).
7. Carefully lift the fan assembly up and out of the engine bay, being cautious not to damage the delicate radiator fins.
8. Installation is the reverse of removal. Afterwards, top off any lost coolant and properly bleed the air from the cooling system.

Cost of Replacement

The cost to replace a Scion xB cooling fan assembly can vary significantly based on the parts used and labor rates.

Note: Prices are estimates and can vary by location and supplier. The high labor estimates often include removing the front bumper and performing a full coolant drain and fill.

Known Issues, Recalls, and TSBs

There are no active recalls or common Technical Service Bulletins (TSBs) from Toyota/Scion specifically for the engine cooling fan assembly on the 2008 Scion xB. Failures are typically due to normal wear and tear on the electric motors over time. The most significant recalls for this model year involve the Takata airbag inflators.

Frequently Asked Questions (FAQ)