Thermostat Kit 160° – Fits Volvo Penta & OMC 4.3L, 5.0L, 5.7L V6/V8 Engines (Replaces 383307, 3856961, 3587597)

Thermostat Kit 160° – Fits Volvo Penta & OMC 4.3L, 5.0L, 5.7L V6/V8 Engines (Replaces 383307, 3856961, 3587597)

This thermostat kit is engineered for Volvo Penta 3.0L, 4.3L, 5.0L, 5.7L, and 5.8L gasoline engines (1993–2003) in V6 and V8 applications. It also fits OMC Cobra 4.3L, 5.0L, 5.7L, and 5.8L engines (1991–1997), including standard and high-output models.

This is a direct replacement for Volvo Penta part numbers 3856961, 3587597, 3852111, 3852071, and 383307. It also cross-references with aftermarket parts from Sierra (18-3677, 18-3653) and GLM (13430, 13060).

• The kit includes a 160° thermostat, a flat gasket, and an O-ring to fit multiple housing types.
• Designed specifically for raw water cooled marine engines.
• Provides a direct, OEM-style fit for a straightforward installation.

Part Number Cross-Reference

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

Compatible Engine Models

Confirm your engine model/year in the table below.

Volvo Penta Applications

OMC Cobra Applications

Technical Specifications

Package Contents

• 1 x 160° Thermostat (Replaces 3856961)
• 1 x Gasket (Replaces 3852111)
• 1 x O-Ring (Replaces 3852071)

Installation Guide

1. Ensure the engine is completely cool before beginning work.
2. Locate the thermostat housing, typically where the main coolant hose connects to the engine.
3. Drain the engine coolant to a level below the thermostat housing to prevent spills.
4. Carefully remove the bolts that secure the thermostat housing cover.
5. Lift the cover away and take note of how the old thermostat is oriented before removing it.
6. Remove the old thermostat and the gasket or O-ring from the housing.
7. Thoroughly clean the mating surfaces of the housing and its cover to ensure a good seal.
8. Install the new 160° thermostat, making sure it is seated in the correct direction.
9. Place the new gasket or O-ring (whichever your application requires) into position.
10. Re-install the housing cover and tighten the bolts to the manufacturer's specified torque.
11. Refill the cooling system with the appropriate type and amount of coolant.
12. Start the engine, let it warm up, and carefully check for any leaks around the thermostat housing.

Troubleshooting & FAQ

Q: How can I confirm this thermostat kit fits my specific engine?

A: This kit is designed for Volvo Penta (1993–2003) and OMC Cobra (1991–1997) V6/V8 engines. Please check the detailed compatible models tables and cross-reference your part number with those listed on our page, such as Volvo Penta 383307 or Sierra 18-3677, to ensure a match.

Q: What are the signs of a failing thermostat?

A: Common symptoms include the engine overheating, running too cold (not reaching proper operating temperature), erratic temperature gauge readings, or visible coolant leaks around the thermostat housing area.

Q: Why is a 160°F thermostat used in these marine engines?

A: A 160°F (71°C) opening temperature is standard for many raw-water-cooled marine engines. It helps the engine reach its ideal operating temperature quickly and maintain it, which is critical for efficient performance, proper combustion, and preventing premature engine wear.

Q: Do I need to use both the gasket and the O-ring included in the kit?

A: No. Your engine's thermostat housing will use either a flat gasket or an O-ring to create a seal. We include both in the kit to cover the different models this part fits, but you will only need to use the one that matches your original setup.

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.
• 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.