Thermostat Service Kit 160°F – Fits Mercruiser V6 & V8 Marine Engines (Replaces 807252Q5)

Thermostat Service Kit 160°F – Fits Mercruiser V6 & V8 Marine Engines (Replaces 807252Q5)

This thermostat service kit is designed for MerCruiser V6 & V8 gasoline engines (4.3L, 5.0L, 5.7L, 7.4L, 8.2L) manufactured from 1987–2016 that require a standard 160°F (71°C) thermostat. It provides a reliable solution for maintaining optimal engine operating temperature.

It is a direct replacement for the following part numbers: Mercury 807252Q5, 807252T5, 807252T8, 8052732, 8072522, 807252T2, 8M0091470, 8M0109441; Sierra 18-3647; GLM 13101; and Mallory 9-43157.

• The complete kit includes a 160°F thermostat, O-ring, housing sleeve, and multiple gaskets for a full service.
• Engineered for a direct replacement installation in standard cooling systems.
• Maintains proper engine temperature to prevent overheating and improve performance.

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 160°F Thermostat (807252T2)
• 1 x O-ring Seal (25-30224)
• 1 x Housing Sleeve (23-806922/806922)
• 1 x Gasket (27-33179-2)
• 1 x Gasket (27-47510)
• 1 x Gasket (27-48818-1)
• 1 x Gasket (27-33918)

Installation Guide

1. Ensure the engine is completely cool before beginning the installation.
2. Drain the engine coolant to a level below the thermostat housing.
3. Loosen and remove the bolts securing the thermostat housing, taking note of its orientation.
4. Carefully lift the housing to remove the old thermostat, gaskets, and sleeve.
5. Thoroughly clean the mating surfaces of the housing and engine block to remove any old gasket material or residue.
6. Insert the new thermostat, ensuring it is correctly seated in the housing or block as per the original.
7. Place the new gaskets and sleeve into position on the clean surfaces.
8. Reinstall the thermostat housing and securely tighten the bolts to the manufacturer's specified torque.
9. Refill the cooling system with the appropriate type and amount of coolant.
10. Start the engine, check for leaks around the housing, and allow it to reach operating temperature to confirm the new thermostat functions correctly.

Troubleshooting & FAQ

How do I confirm this kit fits my MerCruiser engine?
This kit is designed for MerCruiser V6 and V8 engines (4.3L to 8.2L) from 1987-2016 using a standard 160°F thermostat. Please check your engine'''s model and year against the "Compatible Engine Models" table and verify your current part number matches one in the "Part Number Cross-Reference" list.

What are the signs of a faulty thermostat?
Common signs include engine overheating, the temperature gauge reading unusually low, or slow engine warm-up. These symptoms can indicate the thermostat is stuck closed or open.

Is this thermostat suitable for a high-performance engine?
It is not recommended. This kit is engineered for standard cooling systems and may not meet the specific demands of high-performance or modified engines.

OEM vs. Aftermarket?
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.

How fast do you ship and how much does it cost?
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.

What is your warranty and return policy?
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.