Mercury – Quicksilver Water Separating Fuel Filter Kit | Fuel System Component | Corrosion-Resistant Steel | 18458Q4

Overview

Clean fuel means a healthy engine, and the Mercury Marine 18458Q4 Quicksilver Water Separating Fuel Filter Kit makes sure of it. Designed for 1996 and newer Mercury and Mariner V6 EFI outboards, this kit combines a 10-micron fuel filter with a blue water warning sensor to keep contaminants and moisture out of your fuel system. It’s engineered to deliver dependable protection, smooth performance, and easy maintenance — the kind of quality that keeps your outboard running strong through every trip.

Key Features

• Purpose: Removes water and impurities from your fuel before they reach the engine.
• Design: Includes a 10-micron canister-style filter element and a blue screw-in water sensor.
• Material: Built from corrosion-resistant steel with internal epoxy coating and durable exterior paint.
• Performance: Captures fine particles and separates water for cleaner combustion and better fuel efficiency.
• Ease of Service: Simple to replace annually or every 100 hours of operation.

Engine & Boat Compatibility

• Mercury and Mariner V6 EFI outboards built 1996 and later.
• Commonly used on offshore fishing boats, center consoles, performance cruisers, and sport boats.
• Performs equally well in freshwater and saltwater conditions.
• Compatible with systems using the blue-plug water sensor configuration.

Performance & Practical Benefits

The 18458Q4 Fuel Filter Kit delivers the clean, dry fuel your engine depends on. Its 10-micron filter element traps dirt, rust, and debris, while the water sensor monitors for moisture buildup, helping prevent corrosion and fuel contamination.

With a strong internal coating and corrosion-resistant exterior, it’s designed for long life in harsh marine environments. You’ll notice the difference — smoother acceleration, fewer fuel-related issues, and better engine reliability over time. Replacing it regularly keeps your outboard running clean and efficient, trip after trip.

Why Buy OEM

Fuel filtration is not a place to cut corners. Off-brand filters can collapse, leak, or fail to properly separate water from fuel. The Quicksilver 18458Q4 is a genuine Mercury Marine part, designed and tested specifically for Mercury and Mariner EFI systems.

Each filter meets Mercury’s exact flow, pressure, and filtration standards — the same standards used on new engines at the factory. OEM parts ensure a perfect fit, consistent performance, and protection you can trust when you’re miles from shore.

FAQ

Q1: Which engines use this filter kit?
It fits 1996 and newer Mercury and Mariner V6 EFI outboards using the blue water sensor plug.

Q2: What’s included in the kit?
The kit includes the 10-micron water-separating filter element, o-ring, and blue screw-in water sensor.

Q3: How often should I replace it?
Replace it every 100 hours of operation or annually during regular maintenance.

Q4: What’s the difference between this and the 18458Q3 kit?
The 18458Q3 has a black sensor for older (1995 and earlier) engines; the 18458Q4 features a blue sensor for 1996 and newer EFI systems.

Q5: Is it suitable for saltwater use?
Yes. Its epoxy-coated interior and corrosion-resistant finish are built to withstand salt and humidity.