Coolant Temperature Sensor SIERRA 18-5898

Compatible Engines

The original SIERRA 18-5898 coolant temperature sensor is a critical component for the diagnostics and cooling systems of marine propulsion units. Manufactured by the reputable brand SIERRA, this part is designed to provide precise temperature readings within the cooling system, which is essential for the longevity of your engine. For MERCRUISER, OMC, and MCM engines, the proper functioning of this sensor is fundamental to protecting the engine from overheating damage.

Since detailed lists of specific engine models compatible with this part are not provided in the official source data, we recommend verifying compatibility based on the catalog number 18-5898 or the original OE (OEM) number. Each engine may have specific requirements regarding the sensor connector or resistance. If you have any doubts about whether this part fits your unit, please contact our customer support. We are happy to help you verify the serial number and select the correct replacement that will work perfectly in your engine.

Installation and Operation

• Precise Measurements – ensures continuous temperature monitoring, protecting the engine from thermal damage.
• High Build Quality – the SIERRA brand guarantees durability and resistance to the harsh conditions found in the engine compartment.
• Easy Replacement – the standard design facilitates the removal of the old sensor and the installation of the new one.
• Original Equivalents – part number 18-5898 directly references a component that fits many popular marine units.

During installation, pay attention to the condition of the seal and the cleanliness of the threads in the engine block. Improper tightening can lead to leaks, which will quickly lower the coolant level. Regular verification of the sensor's operation is the best way to avoid costly repairs in the future.