Water Pump Impeller for Mercury/Mariner and Chrysler/Force Outboards – Replaces 47-85089-3, Sierra 18-3057
Water Pump Impeller for Mercury/Mariner and Chrysler/Force Outboards – Replaces 47-85089-3, Sierra 18-3057 is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Water Pump Impeller for Mercury/Mariner and Chrysler/Force Outboard...
Water Pump Impeller for Mercury/Mariner and Chrysler/Force Outboards – Replaces 47-85089-3, Sierra 18-3057 is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket water pump impeller is intended as a replacement impeller for selected Mercury/Mariner and Chrysler/Force outboard cooling systems. The impeller circulates cooling water through the engine when the water pump is operating.
Catalog references identify this impeller as a replacement for Mercury Marine 47-85089-3 and Sierra 18-3057. Do not rely on horsepower or brand alone when ordering; water-pump components can vary by model, year, serial number, and gearcase configuration.
- Aftermarket replacement water pump impeller.
- Designed for use in the applicable outboard water-pump assembly.
- Single impeller supplied; housing, gaskets, wear plates, keys, and other service parts are not included unless separately stated.
Part Number Matrix
Use the following references to compare the replacement part with the impeller removed from your engine.
| Brand or Source | Reference Number |
|---|---|
| Mercury Marine | 47-85089-3 |
| Sierra | 18-3057 |
| Chrysler/Force | 47-85089-3 |
Engine Compatibility
This reference is associated with selected Mercury/Mariner and Chrysler/Force outboard cooling-system applications. The available catalog evidence does not establish one universal horsepower, year, or serial-number range for every engine using this reference.
Before ordering: match the complete engine model, year, serial number, water-pump housing, and the original impeller or manufacturer part number. Confirm the impeller dimensions, hub, keyway, blade configuration, and rotation against the original component and service information for your engine.
| Engine Brand | Applicable Reference | Fitment Requirement |
|---|---|---|
| Mercury/Mariner | 47-85089-3 | Confirm exact model, year, serial range, and water-pump assembly. |
| Chrysler/Force | 47-85089-3 | Confirm exact engine application and compare the original impeller before installation. |
Technical Specifications
- Product Type
- Water pump impeller
- Product Format
- Single replacement impeller
- Construction
- Flexible impeller material intended for outboard water-pump service
- Application
- Selected Mercury/Mariner and Chrysler/Force outboard cooling systems
- Replacement References
- Mercury Marine 47-85089-3; Sierra 18-3057
What’s in the Box
- 1 x Water pump impeller
Water-pump housing, gaskets, wear plates, keys, seals, and installation hardware are not included unless specifically listed with the product.
Installation Notes
- Turn off the engine and follow the manufacturer’s service-manual safety procedures.
- Remove the lower unit and water-pump housing according to the engine manufacturer’s instructions.
- Inspect the housing, wear plate, key, seals, and related components for scoring, wear, debris, or damage.
- Compare the replacement impeller with the removed part before installation, including the hub, keyway, dimensions, blade configuration, and rotation.
- Install the impeller in the correct orientation for the pump shaft’s rotation. Use only a lubricant approved by the engine or impeller manufacturer; do not install or operate a new impeller dry.
- Reassemble the water pump and lower unit using the manufacturer’s torque specifications.
- Test the cooling-water discharge and confirm that the engine does not overheat. Never run the outboard without adequate cooling-water supply.
Troubleshooting & FAQ
How do I confirm that this impeller fits my engine?
Match the original part number to 47-85089-3 or Sierra 18-3057, then verify the complete engine model, year, serial number, water-pump housing, and impeller dimensions. Brand and horsepower alone are not sufficient for a reliable fitment check.
What are common symptoms of a worn impeller?
Possible symptoms include reduced or intermittent tell-tale water flow, an overheating warning, higher-than-normal operating temperature, or visible damage when the water-pump housing is opened. Inspect the complete cooling system rather than replacing the impeller alone without checking for related damage.
Should the impeller be replaced with other water-pump parts?
Inspect the housing, wear plate, key, seals, and gaskets during service. Replace worn or damaged components as required by the engine manufacturer’s service procedure. Those parts are not included with this single impeller.
Is this an OEM part?
No. This listing is for an aftermarket replacement impeller. Mercury Marine and Sierra numbers are shown only as manufacturer or aftermarket reference numbers for identification and cross-reference purposes.
Can I install it without checking the serial number?
No. Some outboard models use different impellers or water-pump assemblies within the same horsepower family. Always verify the serial-number range and the original part before installation.
Safety & Important Information
- Verify the part number, dimensions, and physical configuration against the original component before purchase and installation.
- Do not assume compatibility from horsepower, brand, or a visually similar impeller alone.
- Follow the engine manufacturer’s service manual for removal, installation, torque values, lubrication, and testing.
- Professional installation is recommended if you are not experienced with outboard lower-unit or water-pump service.
- This is an aftermarket replacement, not an OEM Mercury or Sierra component.
About Sea Sierra
- Marine Replacement Parts — Practical replacement components for outboard maintenance and repair.
- Application-Focused Information — Use manufacturer references and complete engine details to confirm fitment before ordering.
- Support for Installation Decisions — Compare the original component and consult the correct service information for your engine.
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