3853983 Thermostat Kit for Volvo Penta | JLM Marine

60° Thermostat Kit for Volvo Penta 7.4 8.1 8.2 GI GIE GIL Marine Engines – OEM 3853983

This thermostat kit is designed for Volvo Penta and OMC marine engines, fitting many 4.3, 5.0, 5.7, 5.8 Ford and GM-based V6 and V8 engines including the 7.4, 8.1, and 8.2 GI, GIE, and GIL series. Engineered to maintain optimal operating temperature, this kit ensures reliable cooling system performance in demanding marine environments.

This aftermarket replacement directly crosses to OEM part numbers 3853983, 3856961, and 383307, providing a cost-effective solution without compromising quality or fit.

• Includes 160-degree thermostat, O-ring, and gasket for complete installation
• Compatible with Ford and GM-based V6 and V8 marine engines
• Not compatible with 4-cylinder engines

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.

Technical Specifications

Package Contents

• 160-degree thermostat (1 pc)
• O-ring (1 pc)
• Gasket (1 pc)

Important: Verify all components against your original parts before installation. This kit does NOT fit 4-cylinder engines.

Installation Guide

1. Allow the engine to cool completely and drain the cooling system to a level below the thermostat housing.
2. Disconnect the negative battery cable to ensure safety during the procedure.
3. Remove the upper radiator hose or coolant line connected to the thermostat housing.
4. Unbolt and carefully remove the thermostat housing cover, noting the orientation of the old thermostat.
5. Remove the old thermostat, O-ring, and gasket; clean all mating surfaces thoroughly to remove debris and old gasket material.
6. Install the new thermostat with the correct orientation (spring side typically faces down into the engine block).
7. Position the new gasket on the housing mating surface, ensuring proper alignment.
8. Place the new O-ring into its designated groove on the thermostat or housing.
9. Reinstall the thermostat housing cover and torque bolts to manufacturer specifications in a crisscross pattern.
10. Reconnect the upper radiator hose or coolant line and secure with clamps.
11. Refill the cooling system with the correct coolant mixture and bleed air from the system per manufacturer guidelines.
12. Reconnect the battery, start the engine, check for leaks, and verify proper operating temperature.

Troubleshooting & FAQ

Q: How do I confirm this thermostat kit fits my Volvo Penta engine?
A: Check your engine model against our compatibility table above (4.3, 5.0, 5.7, 5.8, 7.4, 8.1, 8.2 GI/GIE/GIL V6/V8 engines). Verify your current thermostat housing matches the OEM part numbers 3853983, 3856961, or 383307. Note that this kit does NOT fit 4-cylinder engines.

Q: What are the signs that my thermostat needs replacement?
A: Common symptoms include engine overheating, running too cool (poor fuel economy, lack of heat), temperature gauge fluctuations, or coolant leaks around the thermostat housing. A thermostat stuck open or closed will cause temperature regulation issues.

Q: Can I use this 160°F thermostat if my engine originally had a different temperature rating?
A: Always use the thermostat temperature specified by your engine manufacturer. Installing a thermostat with an incorrect temperature rating can lead to overheating, poor performance, or engine damage. Verify your engine's original specification before installation.

Q: How often should I replace my marine engine thermostat?
A: Thermostats should be inspected annually and replaced every 2–3 years or per manufacturer recommendations. Marine environments accelerate corrosion and wear, so regular replacement helps prevent unexpected failures and maintains optimal engine temperature.

Q: Why does the kit include an O-ring and a gasket?
A: Different Volvo Penta and OMC engine models use different sealing methods. Some housings require an O-ring, others use a flat gasket, and some use both. Inspect your original setup and use the appropriate sealing components from the kit to ensure a leak-free installation.

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.