S2335-1 - Textron Aviation Cessna OEM Oil Temperature Sending Unit

S2335-1 – Textron Aviation Cessna OEM Oil Temperature Sending Unit

Available now on the Airparts.aero Marketplace.

Overview

The Textron Aviation S2335-1 is a genuine OEM, flight-critical oil temperature sending unit, or probe, for a wide range of Cessna single-engine aircraft. This is the primary sensor for the oil temperature indication system. Its function is to be immersed in the engine's circulating oil and accurately measure its temperature, converting this thermal data into a proportional electrical signal. This signal is then transmitted to the corresponding oil temperature gauge in the cockpit, providing the pilot with a real-time display of one of the engine's most vital parameters.

This sender is a high-precision, hermetically sealed thermistor housed in a robust, thermally conductive brass or steel body. A thermistor is a type of resistor whose electrical resistance changes predictably with temperature. Critically, this sending unit and the OEM cockpit gauge are engineered and calibrated as a matched set. The accuracy of the pilot's temperature indication is entirely dependent on the specific, non-linear resistance curve of this genuine Textron sender.

Key Features

• Genuine Textron Aviation OEM Part: The only part guaranteed to be perfectly calibrated to the Textron/Cessna oil temperature gauge, ensuring accurate and reliable readings.

• High-Accuracy NTC Thermistor: Utilizes a Negative Temperature Coefficient (NTC) thermistor, providing a sensitive and repeatable resistance change corresponding to oil temperature.

• Engineered as a Matched System: The sender's specific resistance curve is precisely matched to the ratiometric movement of the OEM gauge, a critical factor for instrument accuracy.

• Robust, Sealed Construction: The sensor is housed in a durable brass or steel body and is hermetically sealed to withstand the heat, pressure, and vibration of the engine environment.

• Flight-Critical Sensor: Provides the essential data for proper engine management, from warm-up to in-flight monitoring and shutdown.

Technical Specifications

• Part Number: S2335-1

• Component Type: Oil Temperature Sender / Probe

• OEM Manufacturer: Textron Aviation (Cessna)

• Sensing Technology: Negative Temperature Coefficient (NTC) Thermistor

• Body Material: Brass or Corrosion-Resistant Steel (CRES)

• Thread Size: 5/8"-18 NPT (National Pipe Taper)

Aircraft Compatibility

This oil temperature sender is the specified OEM part for a vast fleet of Cessna's most popular single-engine aircraft, including but not limited to:

• Cessna: 172, 182, 206, 207, 210 and their various sub-models.

Note: This is a flight-critical instrument sensor. The aircraft's specific Illustrated Parts Catalog (IPC) for a given serial number is the final and absolute authority for determining part applicability.

Applications

• Engine Oil Temperature Sensing: The primary sensor that measures the temperature of the engine's lubricating oil.

• Engine Indication System: Provides the variable resistance signal that drives the cockpit oil temperature gauge.

Why Choose S2335-1?

An aircraft's oil temperature indication system is a calibrated system, not just a collection of parts. The gauge in the cockpit is not a simple ohmmeter; it is specifically designed to interpret the unique, non-linear resistance curve of the S2335-1 sender. Using a non-certified, automotive, or "will-fit" sender is an extreme safety risk. Even if it physically fits, its resistance curve will be different, resulting in dangerously inaccurate readings on the gauge. A pilot could see a "normal" indication while the engine is critically overheating, or refuse to take off with a "cold" engine that is actually at a perfect operating temperature. For an accurate, airworthy, and safe temperature indication, there is no substitute for the genuine, system-matched Textron OEM sending unit.

The engineering principle that dictates the pairing of the S2335-1 sender with its specific gauge is the highly non-linear resistance curve of its NTC thermistor. The relationship between the thermistor's resistance (R) and the temperature (T) is an exponential function, which is accurately modeled by the Steinhart-Hart equation: T1​=A+B(lnR)+C(lnR)3. The coefficients A, B, and C are unique to the specific thermistor material and are determined during manufacturing. The cockpit oil temperature gauge is not a simple linear meter; its internal ratiometric mechanism and its dial markings are mechanically and electrically calibrated to linearize and display the temperature based on this exact, known exponential curve. A sender with different Steinhart-Hart coefficients will produce an error on the gauge that is not only incorrect but is also non-linear, meaning it could be fairly accurate at one temperature but dangerously inaccurate at another. This is why system calibration is paramount.

Note: The S2335-1 is a flight-critical engine instrument sensor. Installation must be performed by a certified A&P/IA mechanic. The NPT threads must be coated with a specified, aviation-grade liquid thread sealant. Do not use Teflon tape, as shreds can break off and contaminate the engine oil system. The sender must be torqued to the value specified in the aircraft or engine maintenance manual. A post-installation engine ground run to verify a correct and plausible temperature reading is mandatory.

Documentation

No public-facing OEM specification sheet was located for this proprietary part number. All authoritative technical data, installation procedures, and testing criteria are contained within the official Textron Aviation Maintenance Manual and Illustrated Parts Catalog (IPC) for the applicable aircraft models.

Textron Notes