160° Thermostat Kit – Fits MerCruiser V6 & V8 4.3L-8.2L (Replaces 807252Q5, 8M0091470)

160° Thermostat Kit – Fits MerCruiser V6 & V8 4.3L-8.2L

This thermostat kit is engineered for MerCruiser V6 and V8 inboard/sterndrive engines from 4.3L to 8.2L (model years 1987–2016) that use a standard cooling system and require a 160° thermostat. It provides a reliable, direct-fit replacement to maintain optimal engine operating temperature.

Replaces the following part numbers: MerCruiser 807252Q5, 807252T8, 8052732, 8072522, 807252T2, 8M0091470, 8M0109441; Sierra 18-3647; GLM 13101; Mallory 9-43157.

• Engineered to maintain a consistent 160°F (71°C) operating temperature.
• Designed as a direct OEM replacement for straightforward installation.
• Kit includes a thermostat, plastic housing sleeve, O-ring, and all necessary gaskets for a complete installation.

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 (807252T2)
• 1 x O-Ring (25-30224)
• 1 x Gasket (27-33179-2)
• 1 x Gasket (27-47510)
• 1 x Housing Sleeve (806922/23-806922)
• 1 x Gasket (27-48818-1)
• 1 x Gasket (27-33918)

Installation Guide

1. Ensure the engine is completely cool and disconnect the battery.
2. Drain the engine coolant into a suitable container.
3. Locate the thermostat housing and remove the bolts and hoses connected to it.
4. Remove the old thermostat, sleeve, and gaskets. Note their orientation.
5. Thoroughly clean the mating surfaces of the housing and engine block.
6. Install the new thermostat, sleeve, and gaskets in the correct order and orientation.
7. Re-secure the housing, re-attach hoses, and tighten bolts to the manufacturer's specified torque.
8. Refill the cooling system with the appropriate coolant.
9. Reconnect the battery, start the engine, and check for leaks as it warms up.
10. Top off coolant levels once the engine has cooled down.

Troubleshooting & FAQ

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

A: The best way to ensure compatibility is to check your engine's serial number against the ranges listed in the "Compatible Engine Models" table. You can also match your existing part number to those in the "Part Number Cross-Reference" section. Using our MerCruiser serial number guide can help you pinpoint your model.

Q: What are the common signs of a failing thermostat?

A: Symptoms of a faulty thermostat include engine overheating (if stuck closed) or the engine failing to reach its normal operating temperature (if stuck open). You might also notice erratic temperature gauge readings or coolant leaks around the thermostat housing.

Q: Does this kit include everything needed for the replacement?

A: Yes, this is a comprehensive kit that includes the 160° thermostat, the plastic housing sleeve, and all the required gaskets and O-ring for a standard installation on compatible MerCruiser engines.

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.