Mercury – Quicksilver 140°F Thermostat | For V6 & V8 MerCruiser Engines (1983–2016) | 807252Q4

Overview

Your engine’s cooling system is only as reliable as its thermostat. The Mercury Marine 807252Q4 Quicksilver 140°F Thermostat is engineered for V6 and V8 MerCruiser engines built by General Motors between 1983 and 2016 (excluding high-performance models). This OEM thermostat helps your engine warm up quickly, maintain a steady operating temperature, and run efficiently no matter how hard you’re working it on the water. It’s a simple, durable component that plays a critical role in keeping your engine performing smoothly and safely season after season.

Key Features

• Purpose: Regulates engine temperature for consistent cooling and optimal performance.
• Temperature Rating: Opens at 140°F, maintaining proper operating temperature.
• Compatibility: For V6 and V8 MerCruiser engines (1983–2016) with standard cooling systems.
• Construction: Built from marine-grade materials for corrosion resistance and reliability.
• Ease of Maintenance: Easy to replace using standard hand tools.

Engine & Boat Compatibility

• V6 and V8 MerCruiser engines (1983–2016) made by General Motors
• Not for use on high-performance engines

Performance & Real-World Benefits

The 807252Q4 thermostat ensures your engine stays in its ideal temperature zone — not too cold, not too hot. When the thermostat opens at 140°F, it allows just the right amount of coolant to flow, keeping the engine running efficiently without overheating. A worn thermostat can stick open or closed, leading to rough running, poor fuel economy, or overheating.

This replacement is made from corrosion-resistant, marine-grade materials built to withstand constant exposure to water, heat, and vibration. It installs easily and restores proper temperature regulation, ensuring smoother starts, better performance, and extended engine life.

Why Choose Mercury OEM

The Quicksilver 807252Q4 is a genuine Mercury Marine thermostat, tested and approved for exact fit and performance in MerCruiser engines. Aftermarket thermostats often open at inconsistent temperatures or use cheaper materials that corrode faster, risking costly cooling issues.

Mercury’s OEM design provides the right temperature balance, long service life, and the peace of mind that comes from using the same part trusted by factory technicians and professional boaters alike.

FAQ

Q1: What engines does this thermostat fit?
It fits V6 and V8 MerCruiser engines (1983–2016) made by General Motors, except high-performance models.

Q2: What temperature does it open at?
This thermostat opens at 140°F for proper standard cooling.

Q3: Why replace it?
A bad thermostat can cause overheating or inefficient fuel use. Replacing it keeps your engine running at its best.

Q4: Is it easy to install?
Yes — it’s a direct-fit OEM part that installs quickly with basic tools.

Q5: Why choose OEM over aftermarket?
Mercury OEM thermostats are calibrated and tested to maintain exact temperatures under real marine conditions, offering dependable protection and performance.