Water Pump Impeller – Fits Mercury/MerCruiser V6 & V8 4.3L-8.2L Engines
This water pump impeller is designed for a wide range of Mercury/MerCruiser V6 and V8 sterndrive engines with displacements from 4.3L to 8.2L (262-502 CID). It serves as a crucial component for maintaining proper engine temperature by circulating raw water through the cooling system.
It directly replaces Mercury part numbers 47-862232A2 and 18-3016-1, ensuring a precise fit and reliable performance for the listed compatible models.
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Installation Type: Direct replacement with a press-fit connection.
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Engine Fuel Type: Compatible with gasoline engines.
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Function: Key component in the raw water cooling system.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Mercury |
47-862232A2 |
| Mercury |
18-3016-1 |
| HeuroFosh |
18-3016-1 |
| JLM Marine |
18-3016-1 |
Compatible Engine Models
Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.
| Brand |
Model |
Rated HP |
Stroke |
Years |
OEM Part No. |
Notes |
| MerCruiser |
4.3L MPI |
Various |
4-Stroke |
All |
47-862232A2/18-3016-1 |
V6 Engine |
| MerCruiser |
5.0L/350 MAG |
Various |
4-Stroke |
0M300000 and above |
47-862232A2/18-3016-1 |
V8 Engine |
| MerCruiser |
5.7L/377 MAG |
Various |
4-Stroke |
0M300000 and above |
47-862232A2/18-3016-1 |
V8 Engine |
| MerCruiser |
6.2L MPI |
Various |
4-Stroke |
0M300000 and above |
47-862232A2/18-3016-1 |
V8 Engine, Black Scorpion became SmartCraft compatible at serial #0M391777 |
| MerCruiser |
4.5L |
200-250 HP |
4-Stroke |
All |
47-862232A2/18-3016-1 |
V6 Engine |
| MerCruiser |
6.2L |
300-370 HP |
4-Stroke |
All |
47-862232A2/18-3016-1 |
V8 Engine |
| MerCruiser |
496/8.1L |
Various |
4-Stroke |
All |
47-862232A2/18-3016-1 |
V8 Engine |
| MerCruiser |
8.2L |
Various |
4-Stroke |
All |
47-862232A2/18-3016-1 |
V8 Engine |
Technical Specifications
| Specification |
Value |
| Product Type |
Water Pump Impeller |
| Installation |
Direct replacement |
| Fuel Type |
Gasoline |
| Connection |
Press-fit on pump shaft |
| Housing Color |
Black rubber |
| Fitting Type |
Press-fit |
| Other Technical Attributes |
Raw water cooling system component |
Package Contents
- 1 x Water Pump Impeller (Replaces 47-862232A2/18-3016-1)
Installation Guide
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Safety First: Disconnect the battery before beginning any work.
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Access Lower Unit: Securely position the sterndrive for access to the lower unit.
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Drain Gear Lube: Drain the gear lube from the lower unit to prevent spills.
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Remove Lower Unit: Loosen and remove the bolts securing the lower unit to the upper housing.
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Separate Assembly: Carefully separate the lower unit from the upper housing, watching for the shift shaft.
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Access Pump: Locate and unbolt the water pump housing cover.
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Remove Old Impeller: Take out the old impeller, noting the rotational direction of its vanes.
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Clean and Inspect: Clean the impeller housing and inspect the wear plate and housing for scoring or damage. Replace if necessary.
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Install New Impeller: Lubricate the new impeller and housing. Install the new impeller by rotating the driveshaft in its normal operating direction to correctly seat the vanes.
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Reassemble Pump: Reinstall the water pump housing with new gaskets and torque bolts to manufacturer specifications.
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Reattach Lower Unit: Reassemble the lower unit to the upper housing and refill with the correct type and amount of gear lube.
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Test Operation: Reconnect the battery. Start the engine in a water-fed environment (using flushing muffs or in the water) and confirm a steady stream from the water tell-tale.
Troubleshooting & FAQ
Q: How do I confirm this fits my engine?
A: First, check your engine model and horsepower against the 'Compatible Engine Models' table. For many MerCruiser models, fitment after a certain year depends on the engine serial number. Verify your engine’s serial number is within the specified range (e.g., '0M300000 and above') to ensure compatibility.
Q: What are the signs of a failing impeller?
A: Common signs of a worn or failed impeller include the engine overheating, especially at idle or low speeds; a weak or inconsistent water stream from the "tell-tale" outlet; or discovering brittle, cracked, or broken rubber pieces during inspection.
Q: How often should I replace my water pump impeller?
A: For preventative maintenance, it is recommended to inspect the impeller annually. Replacement is advised every 1-2 years or every 100-200 hours of engine use, whichever comes first. More frequent replacement may be necessary if you operate in saltwater or water with high sediment content.
Q: OEM vs. Aftermarket?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.
Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.
Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.
Important Notes
- Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
- This product is an aftermarket replacement part and is not an OEM component.
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Professional installation is recommended to ensure safety and optimal performance.
Why Choose JLM MARINE?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.