SKU: 6322560996

18-3681 1544683 Thermostat 180°F / 82°C for Volvo Penta D4 D6 D12 | JLM Marine

Sale price$33.34 Regular price$37.04
Save 10%

Pay in installments of $9.26 with ShopPay, AfterPay and Klarna

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Aug 17 - Aug 22

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

Description

18-3681 1544683 Thermostat 180°F / 82°C for Volvo Penta D4 D6 D12 | JLM Marine18 3681 1544683 Thermostat 180F 82C for Volvo Penta D4 D6 D12 This 180F 82C thermostat is engineered to fit Volvo Penta D4, D6, and D12 sterndrive engines, covering a wide range of horsepower ratings from 150 HP to 585 HP across model years 1988 and up. Designed to maintain optimal engine operating temperature, this thermostat ensures reliable thermal management for your marine diesel engine. This aftermarket replacement directly crosses to OEM part

18-3681 1544683 Thermostat 180°F / 82°C for Volvo Penta D4 D6 D12

This 180°F / 82°C thermostat is engineered to fit Volvo Penta D4, D6, and D12 sterndrive engines, covering a wide range of horsepower ratings from 150 HP to 585 HP across model years 1988 and up. Designed to maintain optimal engine operating temperature, this thermostat ensures reliable thermal management for your marine diesel engine.

This aftermarket replacement directly crosses to OEM part numbers 1544683, 1676306, 11000237, 8149182, 1661277, 1303061, and replaces Sierra 18-3681, providing a cost-effective solution without compromising performance.

  • Temperature rating: 180°F / 82°C
  • Direct fit for Volvo Penta D-series sterndrives
  • Complete kit includes thermostat ready for installation

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Brand Part Number Notes
Volvo Penta 1544683 OEM
Volvo Penta 1676306 OEM
Volvo Penta 11000237 OEM
Volvo Penta 8149182 OEM
Volvo Penta 1661277 OEM
Volvo Penta 1303061 OEM
Sierra 18-3681 Aftermarket

Compatible Engine Models

Confirm your engine model/year in the table below.

Brand Model Rated HP Years
Volvo Penta D4 150-300 HP 2003-UP
Volvo Penta D6 235-480 HP 2003-UP
Volvo Penta D12 183-585 HP 1988-UP

Technical Specifications

Specification Value
Temperature Rating 180°F / 82°C
Application Volvo Penta Sterndrive (D4, D6, D12)
OEM Part Number 1544683, 1676306, 11000237, 8149182, 1661277, 1303061
Replaces Sierra 18-3681

Package Contents

This kit contains the following components:

  • 1 × Thermostat (180°F / 82°C)

Installation Guide

  1. Preparation: Allow the engine to cool completely and disconnect the battery to ensure safety during installation.
  2. Drain Coolant: Open the drain plug or remove the lower hose to drain coolant from the system into a suitable container.
  3. Access Thermostat Housing: Locate the thermostat housing on your Volvo Penta engine (typically on the front or side of the block). Remove retaining bolts or clamps securing the housing cover.
  4. Remove Old Thermostat: Carefully extract the old thermostat and inspect the housing for debris or corrosion.
  5. Clean Mating Surfaces: Use a gasket scraper or cloth to remove old gasket material and ensure a clean seal surface on both the housing and cover.
  6. Install New Thermostat: Position the new thermostat in the housing with the temperature-sensing element (spring side) facing into the engine block as indicated by directional markings.
  7. Apply New Gasket/Sealant: Install a new gasket or apply marine-grade sealant as specified by your engine manual.
  8. Reassemble Housing: Reattach the thermostat housing cover and torque bolts to manufacturer specifications in a crisscross pattern.
  9. Refill Coolant: Close drain plugs and refill the cooling system with the recommended coolant mixture. Check the coolant reservoir level.
  10. Bleed Air: Start the engine and allow it to reach operating temperature while monitoring for leaks. Open the bleed valve if equipped to release trapped air.
  11. Check Operation: Verify that the engine reaches normal operating temperature (around 180°F) and that coolant circulates properly through the system.
  12. Final Inspection: Recheck all connections, top off coolant as needed, and confirm no leaks are present around the thermostat housing.

Troubleshooting & FAQ

Q: How do I confirm this thermostat fits my Volvo Penta engine?
A: Cross-reference your engine model (D4, D6, or D12) and year with the compatibility table above. Also verify your original thermostat's OEM part number against the listed cross-references (1544683, 1676306, 11000237, etc.).

Q: What are the signs that my thermostat needs replacement?
A: Common symptoms include engine overheating, slow warm-up times, fluctuating temperature gauge readings, or coolant leaks around the thermostat housing. If the thermostat fails to open, the engine will overheat; if it fails to close, the engine will run too cool.

Q: How often should I replace the thermostat?
A: Thermostats typically last 3–5 years or as recommended in your Volvo Penta maintenance schedule. Replace the thermostat if you experience cooling system issues or during major cooling system service (such as replacing hoses or the heat exchanger).

Q: Can I reuse the old gasket when installing this thermostat?
A: No, always use a new gasket or fresh sealant to ensure a proper seal and prevent coolant leaks. Reusing old gaskets can lead to leaks and compromise cooling system performance.

Q: What is the difference between OEM and aftermarket thermostats?
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.
  • Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

  • Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
  • Fast Global Shipping: Free delivery worldwide in 5–15 days.
  • Direct from Manufacturer: Competitive pricing without compromising quality.
Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 6322560996

Discover Niche Categories That Outsell

Top-Converting Item to Boost Your Average Order

4.8 ★★★★★
Based on 29 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
C
Verified Purchase
Carol A. Brown
Charlottesville, US
★★★★★ 5
Great house pants
Color: Black, Size: 42
these pants are very comfortable and fit well. Perfect for the summer in the desert
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 11, 2026
J
Verified Purchase
Jeff
Birmingham, US
★★★★★ 1
They run short
Color: Khaki, Size: 36
They run short and then when you wash them they get even shorter I wash them in cold water and I don't dry them all the way I pull them out and they still are short
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 9, 2026
R
Verified Purchase
Rosemary Butler
Los Angeles, US
★★★★★ 3
Husband doesn't like!
Color: Navy Blue, Size: 34
My Husband does not like the way they look. The quality and the material.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 28, 2026
M
Verified Purchase
Mrs. Robinson
Grantham, US
★★★★★ 5
Comfy pants!
Color: Camel, Size: 34
These elastic waist pants fit my son perfectly. He has difficulty with buttons and zippers so this is his best bet in order to look a little more fancy. The fit very well and are true to size. They are a little thin, but they look nice.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on February 18, 2026
S
Verified Purchase
SOCRATES
Louisville, US
★★★★★ 5
NICE AND STRETCHY
Color: Navy Blue, Size: 42
These pants are made of a material that seems durable and is definitely comfortable, and they have a stretch band at the waist that can comfortably accommodate many different belly girths-- from slim to portly. The waist also has a drawstring. I'd call these light weight pants, as the material is thin. They aren't baggy at all and fit the natural contours of an average male physique. The pants have two fairly deep front pockets and one small rear pocket that can easily fit a regular-sized wallet. But, I would not recommend carrying a wallet in the rear pocket, as, due to the depth of the pocket being only as deep as the wallet is long, it might slip out as you move around, sitting and rising. If nature calls, and you need to pee, you will have to pull your pants down and excite anyone in the immediate vicinity, as there is no opening, either buttoned or zippered, in the front of the pants. So, in that respect they are kind of like sweatpants. I'd call these pants good for inside the house or wearing on the street. I like them despite the lack of a fly, so I give 5 stars. I see lots of Chinese, Korean, and Japanese guys around who like to wear this type of pant, but these fit nicely for generally larger and more robust Caucasians type physiques as well. You don't have to worry about a belt or a broken fly zipper with these. Of course they are made in China, but due to their vast experience selling clothing to Americans, the manufacturers are well acquainted with big masculine American bodies and their needs.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 9, 2026

recommand products