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Sierra 18-3649 Marine Engine Thermostat

Manufacturer

Sierra

<h3>Sierra: Six Decades of Marine Aftermarket Excellence</h3><p><strong>Sierra</strong> has spent nearly 60 years earning its reputation as one of the most trusted names in the marine aftermarket industry. Originally focused on engine and drive components for boats, the brand has grown into a comprehensive source for nearly everything a boater needs to keep their vessel running at its best — from precision instrumentation to complete engine rebuild hardware.</p><p>Now operating as a brand of Dometic, Sierra manages global aftermarket distribution from a 300,000 sq. ft. facility in Litchfield, Illinois. The Sierra brand today encompasses not only its flagship marine parts line but also well-established marine names like Shields and Moeller, offering boaters a broader catalog than ever before. Whether you own an outboard, inboard, or sterndrive, Sierra's engineering team designs products to meet or exceed OEM specifications.</p><h3>Precision Instrumentation You Can Trust on the Water</h3><p>One of Sierra's most recognized product areas is its marine instrumentation lineup. The brand's <a href="/7570-sierra-gauge-set-1480">gauge sets</a> cover everything from classic analog instrument clusters to advanced digital multi-function displays. Sierra offers packages suited to outboards, sterndrives, and gasoline-powered inboards, with options ranging from coordinated analog kits in styles like Arctic, Eclipse, and Amega to modern touchscreen solutions like the R3 multi-function gauge. Features such as scratch-resistant domed glass lenses, silicone-dampened pointers, and perimeter backlighting make these instruments highly readable in all conditions.</p><p>Behind every accurate gauge reading is a properly calibrated sending circuit. Sierra's <a href="/7570-sierra-gauge-resistor-47908">gauge resistors</a> are a critical part of that chain, ensuring the signals from sensors and sending units are correctly interpreted by your instruments. These components are built to marine-grade standards to resist moisture, vibration, and corrosion — the realities of life on the water.</p><h3>Engine Internals Built to OEM Standards</h3><p>Sierra's history in marine power is perhaps best demonstrated by its deep catalog of engine components. The brand's <a href="/7570-sierra-engine-gasket-set-5404">engine gasket sets</a> cover a wide range of outboard and inboard applications and are engineered to deliver reliable seals in the demanding thermal and chemical environment of a marine engine. For boaters performing seasonal overhauls, top-end rebuilds, or full engine restorations, Sierra gasket kits are a go-to resource trusted by professional marine technicians and DIY boaters alike.</p><h3>A Complete Marine Parts Partner</h3><p>Beyond instrumentation and engine internals, Sierra's catalog spans fuel systems, electrical supplies, steering components, shore power, and more — all covered by what the brand calls an industry-leading warranty. Sierra also maintains a comprehensive parts-finder tool that enables cross-referencing with OEM part numbers from major manufacturers including Mercury, Yamaha, Suzuki, Volvo Penta, and others, making it straightforward to find the right replacement part for virtually any application.</p>

Part Number

18-3649
05/07/2036 10:44 AM
Sale Price

$20.62

In Stock (8)

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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 18-3649 is a high-quality replacement thermostat designed for marine engine cooling systems. This thermostat ensures proper engine temperature regulation by controlling coolant flow, helping to prevent overheating and maintain optimal operating temperatures for reliable performance.

Key Features:

  • Direct replacement for Crusader part number 97895
  • Precision-engineered to OEM specifications for reliable fit and function
  • Constructed from corrosion-resistant materials for marine environments
  • Helps maintain proper engine operating temperature
  • Quality-tested to ensure consistent performance

Sierra Marine is a trusted name in aftermarket marine engine parts, offering dependable replacement components that meet or exceed OEM standards. This thermostat is manufactured to provide long-lasting service in demanding marine applications.

Simply put: Best pricing I've found on the net, quick shipping, no hassles. Will be ordering more products from Autoplicity.

Great quality and and I received very quickly.

Good

fantastic/great prices/simple clean check out

fast and easy

Did not receive any confirmation emails. However contacted them VIA chat and they provided me with information. Shipping is on the slower side.

Easy experience. Thank you.

Just placed order, waiting for shipment to arrive first

Very fast checkout, and best price/shipping I could find.

I have had good experiences so far with Autoplicity.

Great price, very helpful tech support,thanks will buy again<br><br> Chris

Found what I needed- no probelm.

good price , easy to order

Fast and easy

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