Water temperature sensor. Porsche Boxster 986 / 996  ›  99660640501

Water Temperature Sensor

OE Match replacement water temperature sensor for Porsche Boxster 986 and Porsche 996 models.

Fits:

• Porsche Boxster 986 2.5L 1997-99
• Porsche 996 C2 3.4L 1997-08/01
• Porsche 996 C4 3.4L 1997-08/01
• Porsche 996 TURBO 2000-05
• Porsche 996 GT3 MKI 1999-02

Diagram Ref No 29

This essential engine management component monitors coolant temperature and sends information to the engine control unit (ECU), helping regulate fuel delivery, engine performance and cooling system operation.

Designed as an original-style replacement, it helps restore accurate temperature monitoring and reliable engine operation when the original sensor becomes faulty.

What Does the Water Temperature Sensor Do?

The sensor measures engine coolant temperature and sends an electrical signal to the ECU.

This information helps the engine management system adjust fuel mixture, cold-start operation and other temperature-dependent functions, ensuring efficient engine performance.

Why Does It Fail?

Over time, repeated heating and cooling cycles, moisture and electrical deterioration can affect sensor accuracy.

Common problems include:

• Internal sensor failure
• Corroded or damaged electrical connections
• Incorrect or fluctuating temperature readings
• Intermittent electrical signals
• Damage caused by coolant leaks or overheating

When Should It Be Replaced?

Replacement may be necessary if you experience:

• Incorrect or erratic engine temperature readings
• Difficult cold starting or poor warm-up performance
• Increased fuel consumption
• Engine management warning lights
• Cooling fan operation that appears abnormal

Before replacement, check the coolant level, electrical connector, wiring and relevant fault codes to confirm the cause.

Additional 996 variants may have different sensor arrangements. Confirm compatibility using the original part number or vehicle VIN before ordering.

Porsche Boxster 986 & 911 996 Coolant Temperature Sensors

The coolant temperature sensor plays an important role in the engine management system of water-cooled Porsche models, providing accurate temperature information for efficient engine operation.

A faulty sensor can cause incorrect temperature readings, poor cold starting, increased fuel consumption and engine management faults.