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Sierra 18-3039 Water Pump Impeller for Mercury Marine Outboards

Manufacturer

Sierra

<p>For nearly six decades, Sierra has established itself as one of the marine industry's most trusted names in aftermarket engine and drive parts. Founded as a specialized marine parts manufacturer, Sierra has grown into a comprehensive supplier of replacement components, instrumentation, and accessories for both recreational and commercial boating applications. Operating from their 300,000-square-foot distribution center in Litchfield, Illinois, Sierra serves boat owners and marine technicians worldwide with an extensive catalog of parts engineered specifically for the harsh saltwater environment.</p><h3>Marine Engine Excellence</h3><p>Sierra's reputation was built on delivering precision-engineered internal engine components and drive system parts that meet or exceed OEM specifications. Their <a href="/7570-sierra-engine-gasket-set-5404">engine gasket sets</a> provide critical sealing solutions for inboard and outboard motors, while their <a href="/7570-sierra-engine-complete-assembly-15341">engine complete assemblies</a> offer comprehensive replacement options for major overhauls. Each component undergoes rigorous testing to ensure reliability in demanding marine conditions, from corrosion resistance to temperature cycling performance.</p><h3>Instrumentation and Monitoring Systems</h3><p>Accurate instrumentation is essential for boat operators to monitor engine health and prevent costly breakdowns on the water. Sierra's comprehensive line of <a href="/7570-sierra-gauges-200483">gauges</a> includes everything from fuel pressure and temperature indicators to voltmeters and trim gauges, all designed with marine-grade materials that withstand vibration, moisture, and UV exposure. Their <a href="/7570-sierra-tachometer-gauge-1488">tachometer gauges</a> deliver precise RPM readings critical for optimizing engine performance and fuel efficiency. Supporting these instruments, Sierra's <a href="/7570-sierra-gauge-resistor-47908">gauge resistors</a> ensure proper signal conditioning and accurate readings across various sensor types and engine configurations.</p><h3>Expanded Product Portfolio</h3><p>In 2022, Sierra significantly broadened its scope beyond traditional marine engine parts to encompass a wider range of boating accessories and even outdoor power equipment components. This strategic expansion brought established marine brands like Shields and Moeller under the Sierra umbrella, creating a one-stop resource for marine maintenance and replacement parts. The company now offers fuel systems, electrical components, battery charging solutions, and NMEA electronics alongside their traditional engine parts lineup.</p><h3>Quality Backed by Industry-Leading Warranties</h3><p>What sets Sierra apart in the crowded aftermarket marine parts market is their commitment to standing behind every component they manufacture. Their warranty coverage extends beyond simple part replacement—it includes shop labor, haul-out fees, towing charges, and related incidental costs should a warrantied part fail. This comprehensive protection reflects the company's confidence in their manufacturing processes and quality control standards. For boat owners facing repairs far from shore or mechanics working on customer vessels, this peace of mind is invaluable. Whether you're maintaining an outboard motor, rebuilding an inboard engine, or upgrading your boat's instrumentation, Sierra's decades of marine industry experience and commitment to quality make them a reliable choice for keeping your vessel running at peak performance.</p>

Part Number

18-3039
06/01/2036 4:01 PM
Sale Price

$12.91

In Stock (10+)

delivery box

Usually delivered within 2 days

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No Hassle Returns

No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Sierra 18-3039 is a replacement water pump impeller designed for Mercury Marine outboard engines. This critical cooling system component ensures proper water flow through your engine's cooling system, preventing overheating and maintaining optimal operating temperatures.

Key Features:

  • Direct replacement impeller for Mercury Marine outboard applications
  • Compatible with Sierra 18-3239 impeller kit and 18-3446 water pump assembly
  • Precision-molded construction for reliable performance
  • Essential maintenance component for cooling system service

Regular impeller replacement is a crucial part of outboard engine maintenance. Marine impellers should typically be inspected annually and replaced every 2-3 years or according to manufacturer recommendations to ensure reliable cooling system operation.

Quick and easy, just how I like it! Would definitely recommend Autoplicity. Steve Douglas

Quick understandable

Found on Android phone search and they had the item in stock when several others didn't. Immediate shipping and competitive pricing too.

Return customer and will continue to be.

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Great service and quality, the product was correct. I will be a repeat customer

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Recommended by a fellow RegalGS member. Cheaper than Amazon. I haven't had the opportunity to put them on yet, but everything looks good.

So far so good.

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This is my first order from your company. I hope to get my parts quickly to repair my car.

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I was a bit concerned buying from a online retailer I had not done business with before, but Autoplicity is now on my list of preferred vendors. I was sure there would be some problem, as the part I ordered was $73 cheaper than anywhere else online (too good to be true). Well, the part arrived super fast, and was exactly as I ordered. I did not hear from them immediately after ordering, but received confirmation and tracking info when the item shipped, which was two days after ordering. All in all, a great, money saving experience.<br><br>Update:<br>While I am still pleased with the service I received, I find it odd that Autoplicity emailed me and offered me a refund of $5 for writing a review. It has been a couple of weeks since I posted my review, and I have yet to see any credits on my credit card.

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