Sea-Doo 4-TEC Oil Pressure Sensor – P/N 420856533 (RXP, RXT, GTX, GTR, GTI)

Role of the oil pressure sensor on a Rotax 4-TEC engine

The oil pressure sensor is an essential safety component of the Rotax 4-TEC engine. It monitors the lubrication circuit pressure in real time and transmits an electrical signal to the ECU. In the event of a pressure drop, the system triggers an alert or shuts down the engine to prevent internal damage.

A faulty sensor can cause false alerts, untimely engine shutdown, or conversely, mask insufficient pressure and lead to serious damage to the bearings and camshaft.

Technical Specifications

• OEM Part Number: 420856533 / 55233423
• Type: Varistor Type Oil Pressure Sensor
• Signal: Voltage Signal
• Technology: Piezoelectric
• Application: Rotax 4-TEC engines (1503 cm³)
• Origin: OEM quality aftermarket part

Compatibility – Sea-Doo 4-TEC Models

This sensor is compatible with Sea-Doo personal watercraft and tenders equipped with the Rotax 4-TEC 1503 cm³ engine:

• Sea-Doo RXP – all 4-TEC years
• Sea-Doo RXT / RXT-X – all 4-TEC years
• Sea-Doo GTX / GTX Limited – all 4-TEC years
• Sea-Doo GTR – all 4-TEC years
• Sea-Doo GTI SE – 4-TEC versions

Williams Sportjet Tenders

• Williams 435 Sportjet – Sport (Rotax ACE 1503 or ACE 1630)
• Williams 400 / 460 / 520 Sportjet (Rotax ACE 1503 or ACE 1630)

Check your OEM part number (420856533 or 55233423) before ordering. In case of doubt, contact us with your serial number.

Symptoms of a faulty oil pressure sensor

Several signs may indicate a sensor needs to be replaced:

• Oil pressure light permanently or intermittently lit
• Engine fault code related to oil pressure (can be checked via the BRP diagnostic tool)
• Unexpected engine shutdown during navigation
• Mechanically verified correct oil pressure but persistent alert

If mechanical pressure is confirmed normal with an external manometer, the sensor is most likely the cause of the problem.

Sensor Replacement – Installation Tips

The procedure is accessible to an experienced mechanic:

• Turn off the engine and allow it to cool before any intervention
• Disconnect the electrical connector from the sensor
• Unscrew the old sensor (suitable wrench, moderate torque)
• Apply threadlocker to the new sensor's threads if not pre-coated
• Tighten to the torque recommended by BRP (Rotax 4-TEC workshop manual)
• Check for leaks after restarting