Thermostat Repair Kit – Fits OMC Cobra 120/140, Volvo Penta 2.5L & 3.0L (Replaces 3853799, 982554)

Thermostat Repair Kit – Fits OMC Cobra 120/140, Volvo Penta 2.5L & 3.0L

This thermostat repair kit is designed for a range of OMC Cobra and Volvo Penta sterndrive engines. It ensures your engine maintains the correct operating temperature for optimal performance and efficiency.

This kit is a direct replacement for OMC part numbers 3853799, 982554, and 778064; Sierra 18-3670; and GLM 13440.

• Operating Temperature: 160°F (71°C)
• Installation: Direct fit for specified models
• Complete Kit: Includes thermostat and necessary housing gaskets for a full replacement.

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.

OMC

Volvo Penta

Technical Specifications

Package Contents

• 1 x Thermostat (Replaces 3853799/982554/778064)
• 1 x Thermostat Housing Cover Gasket (Replaces 314809/3852127/777906)
• 1 x Thermostat Gasket (Replaces 313416/3852120/777848)

Installation Guide

1. Safety First: Ensure the engine is completely cool before starting. Disconnect the battery.
2. Drain Coolant: Place a drain pan under the thermostat housing and drain the coolant to a level below the housing.
3. Locate Housing: Identify the thermostat housing, typically located where the main coolant hose from the engine connects to the cylinder head or intake manifold.
4. Remove Housing Cover: Loosen and remove the bolts securing the thermostat housing cover.
5. Remove Old Thermostat: Carefully lift the old thermostat out of the housing. Note its orientation.
6. Clean Surfaces: Scrape away any old gasket material from both the housing and the cover mating surfaces. Ensure surfaces are clean and dry.
7. Install New Gaskets: Place the new thermostat gasket and housing cover gasket in position.
8. Install New Thermostat: Insert the new thermostat into the housing, making sure it is oriented correctly (spring-side towards the engine).
9. Reattach Cover: Secure the housing cover and tighten the bolts evenly to the manufacturer's recommended torque.
10. Refill Coolant: Refill the cooling system with the appropriate coolant mixture.
11. Check for Leaks: Reconnect the battery. Start the engine and let it run, checking for any leaks around the thermostat housing.
12. Final Check: Once the engine reaches operating temperature, check the coolant level and top off if necessary.

Troubleshooting & FAQ

Q: How do I confirm this thermostat kit will fit my engine?

A: Please review the Compatible Engine Models tables provided on this page. Cross-reference your engine's brand, model, and year to ensure compatibility. Verifying part numbers against our cross-reference table is also recommended.

Q: What are the signs of a failing thermostat?

A: Common symptoms include engine overheating (temperature gauge in the red) or the engine not reaching its normal operating temperature (running too cool). Inaccurate temperature gauge readings can also indicate a problem.

Q: What is the temperature rating of this thermostat?

A: This thermostat is rated to open at 160°F (71°C), which is the standard specification for the listed engine applications.

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.