Tribeca Temp Sensor Drama: Cooling System Investigation

Recently dealt with similar thermal management issues on a 2008 Subaru Outback. The symptoms match closely, inconsistent temperature readings and delayed engine warm-up are often linked to more than just a clogged cooling grille. In my case, the root cause was a failed thermostat and faulty coolant temperature sensor. The check engine light triggered due to the sensor sending incorrect signals to the ECU. While restricted airflow through the grille can cause engine overheating, it typically wouldnt cause erratic temperature readings or slow warm-up. The cooling system repair involved: Replacing thermostat assembly, Installing new coolant temperature sensor, Full system diagnostic scan, Coolant flush and refill This was a moderately serious issue requiring prompt attention, as continued operation could lead to improper fuel mixture and potential engine damage. The faulty sensor readings meant the engine was running either too rich or too lean. Worth checking the obvious first, ensure the cooling grille is clear and radiator fins are clean. But given the symptoms, recommend having the thermostat and sensors tested professionally to avoid more extensive repairs later.

Thanks for sharing your experience. I had nearly identical symptoms with my Tribeca last winter, erratic temp gauge and slow warm-up times. After diagnosis, it turned out my thermostat and temp sensor needed replacement too. The automotive cooling system issues cleared up completely after the fix. Just wondering, what did the total repair end up costing you? And have you noticed any other cooling system problems since getting it fixed? My repair was several months ago but so far the thermal management has been working perfectly.

After taking my Outback to the mechanic, they found both the thermostat and temperature sensor issues we discussed. The repair also revealed a restricted cooling grille that was causing additional thermal management concerns. They cleared the blockage, which helped improve overall airflow to the radiator. The total repair costs broke down to: Thermostat replacement: 180€, Temperature sensor: 95€, Labor: 145€, Fuse replacement: 52€, Coolant flush and refill: 75€ Everything has worked flawlessly since the fix. The temperature gauge now shows consistent readings, and the engine warms up normally. Most importantly, clearing that radiator blockage and fixing the restricted airflow really helped prevent any risk of car overheating. The cooling system has maintained optimal performance for the past 8 months with no issues. This comprehensive repair was worth every cent considering how critical proper engine cooling is for long-term reliability. The car runs much better now that all cooling components are functioning correctly.

Thanks for the advice. Finally took my Tribeca to the shop last week. The mechanic confirmed the thermostat and temp sensor were shot, just like you all suggested. They also found leaves and debris blocking the radiator, causing some restricted airflow issues. Total bill came to 585€: Thermostat with labor: 195€, Temp sensor replacement: 110€, Cooling system flush: 90€, Diagnostic fee: 75€, Radiator cleaning/service: 115€ The engine cooling system works perfectly now. Temperature gauge shows normal readings and warm-up time is back to normal. Really glad I got it sorted before any serious engine damage occurred. Car runs smoother overall and the check engine light is finally off. Big thanks for steering me in the right direction and helping avoid unnecessary repairs. Understanding the likely causes helped me have an informed conversation with the mechanic.