171960 Temperature Sender for MerCruiser OMC 4-cyl 120-225HP V6 V8 | JLM Marine

Temperature Sender 171960 – Fits MerCruiser OMC 4-Cyl 120-225HP V6 V8 Engines

This Temperature Sender is engineered to deliver accurate engine temperature readings for MerCruiser Stern Drive, OMC Inboard, OMC Stern Drive, and Crusader V6 V8 Engines. Designed as a direct replacement for OEM part 171960, it ensures reliable performance across a wide range of marine applications including 4-cylinder 120-225 HP and V6/V8 configurations.

This sender replaces multiple OEM part numbers including 171960, 34625, 97258, 97258A1, and aftermarket equivalents from Sierra (18-5898) and other manufacturers, providing broad compatibility and easy sourcing for your engine maintenance needs.

• Thread Size: 1/2" (12.7mm) -14 NPT for secure installation
• Terminal Type: 10-32 stud for reliable electrical connection
• Temperature Range: 240° DS for comprehensive monitoring

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below.

Technical Specifications

Package Contents

Your package includes the following component:

• 1 × 1/2" Temperature Sender 171960

Installation Guide

1. Preparation: Ensure the engine is completely cool and disconnect the battery to prevent electrical shorts.
2. Locate the Sender: Find the existing temperature sender on your engine block, typically near the thermostat housing or cylinder head.
3. Disconnect Wiring: Carefully remove the electrical connector from the old sender terminal.
4. Remove Old Sender: Using an appropriate wrench, unthread the old sender counterclockwise. Have a rag ready to catch any coolant that may drip.
5. Inspect Threads: Clean the mounting hole threads and inspect for damage or debris.
6. Apply Sealant: Apply a small amount of thread sealant compatible with coolant to the new sender's threads (follow manufacturer recommendations).
7. Install New Sender: Thread the new sender clockwise by hand first, then tighten securely with a wrench. Do not overtighten.
8. Reconnect Wiring: Attach the electrical connector firmly to the 10-32 stud terminal on the new sender.
9. Check Coolant Level: Top off coolant if necessary and check for leaks around the sender.
10. Reconnect Battery: Restore battery connection and start the engine.
11. Verify Operation: Monitor the temperature gauge to ensure it displays accurate readings as the engine warms up.
12. Final Inspection: After the engine reaches operating temperature, shut it down and recheck for any coolant leaks around the sender.

Troubleshooting & FAQ

Q: How do I confirm this temperature sender fits my engine?
A: Verify your engine model matches the compatibility list (MerCruiser 4-cyl 120-225 HP V6 V8, OMC Inboard/Stern Drive, Crusader V6 V8). Cross-reference your current sender's part number with the numbers listed above (171960, 34625, 97258, 97258A1, Sierra 18-5898, etc.). Confirm the thread size is 1/2"-14 NPT and terminal type is 10-32 stud.

Q: What are the signs that my temperature sender has failed?
A: Common symptoms include erratic temperature gauge readings, a gauge that reads extremely high or low regardless of actual engine temperature, a gauge stuck at zero, or an illuminated temperature warning light when the engine is not overheating. If you experience these issues, test the sender with a multimeter or replace it to restore accurate monitoring.

Q: How often should I replace the temperature sender?
A: Temperature senders don't have a fixed replacement interval but should be inspected during regular maintenance. Replace the sender if you notice inaccurate readings, corrosion on the terminal or threads, coolant leaks around the unit, or any physical damage. Many technicians replace senders every 5-7 years as preventive maintenance.

Q: Can I use this sender if my original has different terminal or thread specifications?
A: No, you must match both the thread size (1/2"-14 NPT) and terminal type (10-32 stud) to your original sender. Installing a sender with incorrect specifications will result in improper fit, potential leaks, or electrical connection failure. Always verify dimensions before purchasing.

Q: What is the difference between this aftermarket sender and the OEM part?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.