Quicksilver Replacement Thermostat for MerCruiser V6/V8 — 160°F 1987–2016 OEM-fit, Standard Cooling

Quicksilver 807252Q5 is a 160°F replacement thermostat engineered for standard-cooling V6 and V8 MerCruiser engines (non‑high‑performance) from 1987–2016.

This OEM-spec thermostat restores correct coolant flow and operating temperature for compatible MerCruiser sterndrives and inboard/outboard engines. Manufactured to Mercury Marine original equipment specifications by Quicksilver, it’s intended for owners and technicians who need a direct-fit replacement that maintains engine efficiency and helps protect components from running too cool or too hot.

Which MerCruiser engines use the 807252Q5 thermostat?

This thermostat fits many V6 and V8 MerCruiser engines built between 1987 and 2016 that use standard cooling and require a 160°F unit. It does not replace thermostats for high‑performance variants or models that specify a different temperature rating.

• Compatible with GM‑based MerCruiser V6 and V8 engines (1987–2016)
• Intended for standard cooling configurations only
• Not for high‑performance engines or models requiring other temp ratings
• Verify part number and temperature spec in your owner’s or service manual

How does swapping to this 160°F thermostat affect engine performance?

Using the correct 160°F thermostat helps the engine reach and hold its designed operating temperature, which supports fuel efficiency, consistent power delivery, and reduced wear. Running too cool or too hot can change fuel burn and component longevity.

• Helps maintain optimal combustion and fuel efficiency
• Stabilizes oil temperature for consistent lubrication
• Reduces thermal stress on gaskets and seals
• Restores proper coolant circulation timing

Is the 807252Q5 easy to install and what tools are needed?

Yes — the thermostat is designed for straightforward replacement using common shop tools. Most techs and seasoned DIYers can perform the swap with the engine cool and following removal/replacement steps in the service manual.

• Requires basic hand tools: sockets, wrenches, screwdrivers
• Follow owner’s manual for correct removal and gasket/seat inspection
• Inspect housing and flush coolant if contaminated before installing
• Torque fasteners to OEM specs to avoid leaks or distortion

Why choose Quicksilver over generic aftermarket thermostats?

Quicksilver produces parts to meet Mercury Marine OEM specifications, so fit, materials and temperature calibration match factory standards. That consistency simplifies maintenance and reduces the chance of cooling-system surprises after installation.

• Engineered and tested to OEM tolerances and durability standards
• Direct replacement fit for MerCruiser applications—no modification needed
• Backed by Quicksilver’s long history in marine parts and accessories
• Helps preserve engine performance and resale value

Who is this for: Boat owners, marine technicians, and restoration projects using MerCruiser V6 or V8 engines (1987–2016) with standard cooling that require a 160°F thermostat. Choose this Quicksilver part when you need a reliable, OEM‑grade replacement to maintain correct operating temperature and dependable cooling system performance.