Mercury – Water Pump Impeller | Cooling System Component | Fiberglass-Reinforced Insert | 89984T3

Overview

Keeping an engine cool is one of those things you never think about until it stops working the way it should. Whether you’re running an older sterndrive, a classic Mercury outboard, or a dependable Mariner setup, steady water flow is what keeps you moving without worry. The Quicksilver 89984T3 Water Pump Impeller brings that confidence back. It’s the kind of part you install once and immediately feel better about, knowing your cooling system has fresh, flexible vanes and a solid, bonded hub to keep the water moving exactly the way the engine needs it to.

Key Features

• OEM water pump impeller for select sterndrive and outboard applications
• High-flexibility elastomer vanes maintain strong flow across hot and cold conditions
• Fiberglass-reinforced center insert bonded to the vanes for improved durability
• Designed for corrosion resistance in freshwater and saltwater environments
• Engineered to Mercury Marine specifications for proper fit and cooling performance

Engine & Boat Compatibility

Because the 89984T3 is used across multiple systems, owners should confirm compatibility with their specific engine model. Typical applications include:

• Select Mercury and Mariner outboards
• Various MerCruiser sterndrive platforms using this impeller size
• Engines requiring a fiberglass-reinforced, bonded-insert impeller
• Common on:
  • Classic runabouts
  • Aluminum fishing boats
  • Older cruisers and stern-drive family boats
  • Utility workboats and multi-purpose rigs

(As always, checking your owner’s manual or service guide ensures the perfect match.)

Performance & Practical Benefits

A water pump impeller isn’t glamorous, but it’s one of the most important parts of your engine’s health. Over time, the vanes dry out, stiffen, or crack especially after long off-season storage. Even slight wear can lead to lower water flow, which eventually shows up as warmer running temperatures or a weak telltale stream.

The 89984T3 is built to solve that. Its elastomer vanes stay flexible through cold morning starts and summer heat, which means they stay tight against the housing and push a full, steady volume of cooling water. The fiberglass-reinforced center insert is bonded to the vanes for a reason: it prevents slip, tearing, or hub separation under load, a common failure point with cheaper aftermarket versions.

Boaters often notice the difference right away — smoother idle, more predictable temperature readings, and a stronger, more confident water stream. For sterndrive engines, proper cooling also protects the exhaust components and reduces long-term thermal stress. For outboards, it means easier starts, better efficiency, and less strain on the powerhead.

Whether you fish shallow rivers, run saltwater bays, or cruise inland lakes, this impeller provides the foundation for reliable cooling you can trust every trip.

Why Buy OEM

Mercury’s cooling systems are designed around very specific material stiffness, vane spacing, and bonding strength. Aftermarket impellers may “fit,” but they rarely match the durability and precise flow rate of an OEM component. The 89984T3 gives you Mercury’s engineered reliability — the same feel, performance, and fit the factory intended. For any engine you want to keep running for years, OEM simply makes more sense.

FAQ

Q1: Which engines does the 89984T3 impeller fit?

It fits select Mercury and Mariner outboards, as well as MerCruiser sterndrive models that use this impeller type. Always verify with your manual.

Q2: What makes this impeller better than aftermarket versions?

The fiberglass-reinforced bonded insert and OEM elastomer material offer longer life, proper stiffness, and stronger water flow.

Q3: How can I confirm it’s the correct replacement?

Match your engine’s model and year to the cooling system diagram or check your owner’s manual for the correct part number.

Q4: Is it suitable for saltwater?

Yes — it’s built with corrosion-resistant materials. Just flush after saltwater use.

Q5: Is installation straightforward?

Most boat owners with basic tools and a service manual can install it in under an hour.

• Supersessions
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