SKU: 93066173549

18-3621 Thermostat for Volvo Penta 3.0L | JLM Marine

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Description

18-3621 Thermostat for Volvo Penta 3.0L | JLM Marine18 3621 Thermostat for Volvo Penta 3. 0L JLM Marine This high quality aftermarket thermostat kit is engineered specifically for Volvo Penta 3. 0L marine sterndrive engines (1996 UP). It delivers reliable temperature regulation to keep your engine running at optimal performance in demanding marine conditions. This kit directly replaces OEM part number 18 3621 and includes the thermostat, gasket, and O ring required for a complete installation. Complete

18-3621 Thermostat for Volvo Penta 3.0L | JLM Marine

This high-quality aftermarket thermostat kit is engineered specifically for Volvo Penta 3.0L marine sterndrive engines (1996-UP). It delivers reliable temperature regulation to keep your engine running at optimal performance in demanding marine conditions.

This kit directly replaces OEM part number 18-3621 and includes the thermostat, gasket, and O-ring required for a complete installation.

  • Complete kit with thermostat, gasket, and O-ring
  • Designed for Volvo Penta 3.0L sterndrive engines
  • Ensures proper engine temperature control and longevity

Part Number Cross-Reference

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

Brand Part Number Notes
JLM Marine 18-3621 Complete Kit
Volvo Penta 3853799 Thermostat
Volvo Penta 311069 Gasket
Volvo Penta 3852096 Gasket
Volvo Penta 3789161 O-Ring

Compatible Engine Models

Confirm your engine model/year in the table below.

Brand Model Years
Volvo Penta 3.0L SternDrive 1996-UP

Technical Specifications

Specification Value
OEM Reference 18-3621
Application Volvo Penta Marine SternDrive Engines
Engine Displacement 3.0L
Year Range 1996-UP

Package Contents

  • 1 × Outboard Thermostat
  • 1 × Gasket
  • 1 × O-Ring

Installation Guide

  1. Ensure the engine is completely cool before beginning any work. Drain the coolant from the system into a suitable container.
  2. Locate the thermostat housing on your Volvo Penta 3.0L engine. Remove the retaining bolts or clamps securing the housing cover.
  3. Carefully lift off the thermostat housing cover and remove the old thermostat. Note the orientation of the thermostat before removal.
  4. Clean all mating surfaces on the housing and cover thoroughly, removing old gasket material and debris. Ensure surfaces are dry and free of contaminants.
  5. Install the new O-ring into the designated groove on the thermostat or housing as specified by your engine's design.
  6. Position the new thermostat into the housing with the correct orientation (spring side typically faces the engine block). Place the new gasket onto the housing.
  7. Reinstall the thermostat housing cover and tighten bolts to the manufacturer's specified torque in a criss-cross pattern. Avoid over-tightening to prevent warping.
  8. Refill the cooling system with the recommended coolant mixture. Bleed air from the system according to Volvo Penta procedures.
  9. Start the engine and allow it to reach operating temperature. Monitor for leaks around the thermostat housing and check coolant level.
  10. After the engine has cooled, recheck coolant level and top off if necessary.

Troubleshooting & FAQ

Q: How do I confirm this thermostat kit fits my Volvo Penta engine?
A: Verify that you have a Volvo Penta 3.0L sterndrive engine manufactured in 1996 or later. Cross-reference the OEM part numbers (3853799 for thermostat, 311069/3852096 for gasket, 3789161 for O-ring) with your engine's service manual or existing parts.

Q: What are the signs that my thermostat needs replacement?
A: Common symptoms include engine overheating, running too cool (not reaching normal operating temperature), fluctuating temperature gauge readings, or coolant leaks around the thermostat housing. If you notice any of these issues, inspect and test your thermostat.

Q: How often should I replace the thermostat on my Volvo Penta engine?
A: Thermostats should be inspected annually and typically replaced every 3-5 years or per your engine manufacturer's maintenance schedule. Replace immediately if you experience temperature regulation issues or if the thermostat fails testing.

Q: Is this an OEM part or aftermarket replacement?
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: 93066173549

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A
Atherney Family Farm
Houston, US
★★★★★ 5
Nice elegant suit for any occasion.
Color: Light Blue, Size: 12, Color: Light Blue, Size: 12
The suit set is very nice, the fabric material is durable and soft. Overall stitching is tight with nice surging of the hems and great construction on the shoulders. Buttons and button wholes are well done. I'm going to iron in the creases on the front of the pants because they weren't folded properly for shipping. The material does hold on to wrinkles so don't be afraid of your iron to get a super sharp look. The color is a soft baby blue that stands out in a crowd of black suits. With the option of an elastic tie or clip on bowtie this is everything you need to make him look presentable for a variety of occasions. My only complaint about this suit kit is the dress shirt is stiff and thin. I found some loose threads that I don't trust to not get played with. I'll probably trade it out for something with a little more cotton. As far as cost goes mid range, but definitely worth the cost. I might consider something with a vest if it's a super formal event, but I'm very happy with how this suit comes together.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 18, 2026
M
Martin V.
Lake Worth, US
★★★★★ 5
Modern luxury with summer fabric that performs above its price!
Color: Beige, Size: 14, Color: Beige, Size: 14
Wow! My son wore it for Easter Sunday and this suit fits the bill! The linen material is spot on--not too heavy and not too light especially since the weather is warming up now. The jacket is quality made--the design is modern executive, the stitches are strong no flaws to note. The pants are tad bit longer but that's okay, build quality is also great. The white shirt is decent and matches well with the rest of the set. The bow tie and tie itself is a great complimentary to the set, though optional to wear. The whole set just has that quality you would really look for in the price range you would want to pay. Overall, best value for for the, wear right outside the bag, maybe a light ironing otherwise it's perfect! I highly recommend it, no complaints here very happy with this suit!
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Reviewed in the United States on April 5, 2026
A
Ariel B.
Lake Worth, US
★★★★★ 4
Heavy linen character, but a beautifully tailored suit!
Color: Beige, Size: 4, Color: Beige, Size: 4
This is a really nice linen suit! The jacket is beautifully made and well-tailored, with a fun speckled texture that has lots of pretty color variation (we ordered the beige). When I placed it side by side with a similar linen suit from another brand, the difference in the linen texture was really noticeable — this had a much stronger linen character that stands out! It has three useful pockets on the outside of the jacket, which is great for little hands. The only downside is that one of the inside pockets is just for show (faux), which was a bit surprising and somewhat disappointing for my little guy. The pants have pockets too, but they aren’t very deep — perfect for small treasures, but not much more. The pants are made from a lighter, thinner single-layer linen compared to the fully lined, double-layer jacket, which makes sense for comfort and easy movement. The pants didn’t come with a front crease ironed in, so you’ll want to press one yourself. The linen did pick up some creases from being folded in the package, but it doesn’t seem quite as wrinkly as some other linen fabrics I’ve tried. Still, like most linen clothes, especially for boys, the pants will need occasional ironing to keep them looking neat and crisp, especially after a day of play and general wear. The structured, lined jacket stays looking smoother and more put-together with less effort. It also came with a bow tie, a neck tie, and a tuxedo-style white shirt as extras. The ties aren’t great quality — they’d work fine for quick photos but probably won’t hold up to much actual wear. The formal white shirt feels a bit funny paired with the casual linen suit, but I don’t mind at all. We already have white shirts that we prefer, so we’ll use those instead. For us, the extras are really just bonus items we won’t plan on using. Overall, it’s a handsome little suit that’s perfect for special occasions like weddings, family photos, or holiday events. My kid looked adorable in it! The stronger linen texture on the jacket gives it a premium feel that I really like. Just be ready for a bit of extra care with the pants to keep everything sharp.
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Reviewed in the United States on April 8, 2026
C
chzgr8er
Port Orchard, US
★★★★★ 5
Great suit set
Color: Light Grey, Size: 4
It is incredibly attractive and includes everything a young child needs for a special occasion. The material is a 75% polyester and 25% linen blend, and the outer fabric feels remarkably smooth. Its unstructured design allows for an attractive, natural drape, and the blend conveniently allows for machine washing at home. As is typical with linen-based materials, the fabric can be naturally stiff and prone to wrinkling, so I recommend ironing or steaming it before use. The lightweight feel makes it an excellent choice for the spring, summer, and fall months. Overall, this suit offers exceptional value for the price.
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Reviewed in the United States on April 12, 2026
J
Verified Purchase
Joseph
West Palm Beach, US
★★★★★ 5
A good First Communion suit
Size: 6, Color: White, Size: 6, Color: White
This suit looks and feels really nice even though it’s not 100% linen. My son is an average size 7 year old, but I got a size 6 so that the fit would be nice and snug and not loose and baggy. It was the right choice. Comes with a bow tie which is nice, a tie (which is very cheap and poorly made) and a pocket square.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 29, 2026

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