Thermostat Kit – Fits Mercury Verado V6/V8 175-300HP (Replaces 8M0162139, 8M0137816)

Thermostat Kit – Fits Mercury Verado V6/V8 175-300HP (Replaces 8M0162139, 8M0137816)

This thermostat kit is designed for Mercury/Mariner Verado 175-300HP V6 3.4L & V8 4.6L 4-Stroke engines from 2018 and newer (serial number 2B529482 and above).

It is a direct replacement for Mercury OEM part numbers 8M0137816 and 8M0162139.

• Engineered for direct-fit installation, matching OEM specifications.
• Features a corrosion-resistant stainless steel housing for durability in marine environments.
• Designed with a self-cleaning mechanism that allows contaminants to be flushed from closing surfaces.

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. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

Technical Specifications

Package Contents

• 1 x Thermostat (8M0162139)

Installation Guide

1. Ensure the engine is cool and disconnect the battery. Place a container under the engine to catch draining coolant.
2. Locate the thermostat housing on the engine block. It's typically where the main coolant hose from the radiator attaches.
3. Carefully remove the bolts securing the housing. You may need to gently tap the housing to break the seal.
4. Note the orientation of the old thermostat before removing it from the housing.
5. Clean both the housing and the engine block mating surfaces thoroughly, removing all old gasket material.
6. Install the new thermostat in the same orientation as the original.
7. Re-secure the thermostat housing with a new gasket, if applicable, and tighten the bolts to the manufacturer's specified torque.
8. Reconnect all hoses, refill the cooling system with the appropriate coolant, and reconnect the battery.
9. Start the engine and let it warm up, checking carefully for any leaks around the thermostat housing. Top off the coolant as needed.

Troubleshooting & FAQ

Q: How do I confirm this thermostat fits my Verado engine?

A: This thermostat fits a wide range of Mercury Verado V6 and V8 engines (2018 and newer). The most reliable way to confirm fitment is to match your engine's serial number against the ranges listed in the compatibility table. For this part, your serial number should be 2B529482 or higher for most models.

Q: What are the signs of a failing thermostat?

A: Common symptoms include engine overheating (if stuck closed) or the engine taking too long to reach its proper operating temperature (if stuck open). An erratic temperature gauge reading can also indicate a problem.

Q: How often should I replace my engine's thermostat?

A: Thermostats don't have a fixed replacement schedule, but they are a critical component for engine health. Many mechanics recommend replacing them as a preventative measure every 300-500 hours or every few years, especially if you operate in saltwater.

Q: OEM vs. Aftermarket?

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.