Quicksilver Thermostat for MerCruiser V6/V8 160°F — Direct-Fit OEM Replacement 1987–2016

The Quicksilver 807252Q5 is a 160°F replacement thermostat engineered to restore correct cooling temperature for MerCruiser V6 and V8 engines (1987–2016) that use standard cooling setups.

This OEM-grade Quicksilver thermostat matches Mercury Marine specifications and is designed as a direct-fit replacement for many General Motors–based MerCruiser sterndrive and inboard engines from model years 1987 through 2016. It helps maintain the engine's intended operating temperature, supporting reliable performance and efficient fuel use without modifying factory cooling characteristics. Quicksilver has supplied marine parts for decades and emphasizes parts that fit precisely and endure tough marine environments.

How does this thermostat affect engine performance?

Keeping the engine at its designed temperature allows combustion, lubrication, and emissions systems to work as intended. A properly functioning 160°F thermostat reduces excessive warm-up time and prevents overheating that can harm components. Replacing a failed thermostat restores predictable engine behavior and can improve throttle response and efficiency.

• Maintains target coolant temperature around 160°F for stable operation
• Prevents prolonged cold running that increases wear and fuel consumption
• Helps avoid overheating-related damage to gaskets and cylinder heads
• Designed to meet Mercury Marine original equipment tolerances

Will this fit my MerCruiser engine and how do I check compatibility?

The 807252Q5 is intended for V6 and V8 MerCruiser engines built on General Motors platforms from 1987 to 2016 that require a 160°F thermostat. It is not intended for high-performance or modified coolant systems—always verify the temperature spec in your owner's or service manual first. Fitment is typically straightforward because it’s produced to original-equipment dimensions.

• Compatible with GM-based MerCruiser V6 and V8 engines, 1987–2016
• Not for high-performance engine variants—check factory specs
• Confirm required thermostat temperature in your manual before ordering
• Direct-replacement design for hassle-free installation with basic tools

How difficult is installation and what tools are needed?

Replacement is generally a routine maintenance task for anyone comfortable with basic marine engine work. You’ll need common shop tools and follow standard removal and installation procedures outlined in the service manual. If corrosion or restricted passages are present, expect slightly longer service time to clean the housing and mating surfaces.

• Installs using standard hand tools—no specialty tools required
• Follow your owner's manual for proper removal and sealant recommendations
• Inspect thermostat housing and coolant passages while replacing
• Allow coolant to drain and the engine to cool before starting work

What are the quality and warranty expectations for a Quicksilver thermostat?

Quicksilver parts are engineered to align with Mercury Marine's original equipment specifications and subjected to rigorous testing. This thermostat is manufactured for durability in marine conditions, providing predictable operation under saltwater or freshwater use. Warranty coverage and return policies depend on the retailer—keep purchase documentation and inspect parts on delivery.

• Built to meet Mercury Marine OEM specifications
• Manufactured for resilience in marine environments
• Backed by Quicksilver’s reputation for OEM-grade components
• Check retailer for specific warranty or return terms

Who is this for: This Quicksilver 807252Q5 thermostat is aimed at boat owners, marine technicians, and restoration specialists maintaining GM-based MerCruiser V6 or V8 engines from 1987–2016 that require a 160°F thermostat. It suits anyone seeking an OEM-equivalent replacement that preserves factory cooling behavior and straightforward installation with standard tools. If your engine is a high-performance variant or lists a different thermostat temperature, select the temperature specified by your manual instead of this part.