Thermostat (160°F/71°C) – Fits MerCruiser V6/V8 Alpha/Bravo Engines (Replaces 8M0109441, 807252T2)
Thermostat (160°F/71°C) – Fits MerCruiser V6/V8 Alpha/Bravo Engines (Replaces 8M0109441, 807252T2) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
U.S. orders usually arrive within 6–15 days, depending on stock location and destination.
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Thermostat (160°F/71°C) – Fits MerCruiser V6/V8 Alpha/Bravo Engines...
Thermostat (160°F/71°C) – Fits MerCruiser V6/V8 Alpha/Bravo Engines (Replaces 8M0109441, 807252T2) is backordered and will ship as soon as it is back in stock.
Product Details
This replacement Thermostat (160°F/71°C) – Fits MerCruiser V6/V8 Alpha/Bravo Engines is engineered for Mercury MerCruiser V6 and V8 engines from 1987 to present using standard cooling systems. It ensures your engine operates at the correct temperature for optimal performance and longevity.
This part is a direct interchange for Mercury/MerCruiser part numbers 8M0109441, 8M0091470, 807252T2, 8072522, 8052732, and Sierra 18-3649.
- Engineered for direct replacement using standard tools.
- Manufactured to OEM specifications in an ISO 9002 certified factory.
- Compatible with all standard marine fuel types.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Notes |
|---|---|---|
| Mercury/MerCruiser | 8M0109441 | Current OEM number. |
| Mercury/MerCruiser | 8M0091470 | Superseded by 8M0109441. |
| Mercury/MerCruiser | 807252T2 | Superseded by 8M0091470. |
| Mercury/MerCruiser | 8072522 | Superseded by 807252T2. |
| Mercury/MerCruiser | 8052732 | Superseded by 8072522. |
| Sierra | 18-3649 | Aftermarket cross-reference. |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For MerCruiser applications, serial number ranges are the most accurate way to confirm fitment. Many models listed below are compatible across multiple ranges.
| Brand | Model | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|
| MerCruiser | 350 MAG MPI ALPHA/BRAVO | 4-Stroke | 1A300000 & Up | 8M0109441 | Previously 807252T2 |
| MerCruiser | 350 MAG MPI SKI | 4-Stroke | 0M300000–0M316999 | 8M0109441 | Previously 807252T2 |
| MerCruiser | BLACK SCORPION 350 MAG MPI | 4-Stroke | 0M391600–0W689999 | 8M0109441 | Previously 807252T2 |
| MerCruiser | 377 MAG MPI BRAVO | 4-Stroke | 1A300000 & Up | 8M0109441 | Previously 807252T2 |
| MerCruiser | SCORPION 377 | 4-Stroke | 0W698433 & Up | 8M0109441 | Previously 807252T2 |
| MerCruiser | 4.3L CARB ALPHA/BRAVO | 4-Stroke | 0M615000–0W649999 | 8M0109441 | Previously 807252T2 |
| MerCruiser | 4.3L MPI ALPHA/BRAVO | 4-Stroke | 0M615000–0W309999 | 8M0109441 | Previously 807252T2 |
| MerCruiser | 5.0L MPI ALPHA/BRAVO | 4-Stroke | 1A300000 & Up | 8M0109441 | Previously 807252T2 |
| MerCruiser | 5.7L EFI MIE GM 350 V-8 | 4-Stroke | 1997, 0K040300–0K261160 | 8M0109441 | Previously 807252T2 |
| MerCruiser | 5.7L MPI MIE EC | 4-Stroke | 1A090000 & Up | 8M0109441 | Previously 807252T2 |
| MerCruiser | 6.2L MPI MIE EC | 4-Stroke | 1A091600 & Up | 8M0109441 | Previously 807252T2 |
| MerCruiser | MX 6.2L MPI BRAVO | 4-Stroke | 0L680003–0M299999 | 8M0109441 | Previously 807252T2 |
| MerCruiser | 502 MAG MPI BRAVO (GEN VI) | 4-Stroke | 1998, 0L017000–0L085432 | 8M0109441 | Previously 807252T2 |
| MerCruiser | 454 MAG MPI BRAVO (GEN VI) | 4-Stroke | 1998, 0L010029–0L058399 | 8M0109441 | Previously 807252T2 |
| MerCruiser | SCORPION 350 | 4-Stroke | 0W698433 & Up | 8M0109441 | Previously 807252T2 |
| MerCruiser | 3.0L TKS Plus | 4-Stroke | 1G404114 & Up | 8M0109441 | Previously 807252T2 |
| MerCruiser | 350 MPI ALPHA | 4-Stroke | 1G400000 & Up | 8M0109441 | Previously 807252T2 |
| MerCruiser | 357 Alpha 4V | 4-Stroke | 1G400000 & Up | 8M0109441 | Previously 807252T2 |
| MerCruiser | 357 Mag Bravo 4V | 4-Stroke | 1G400000 & Up | 8M0109441 | Previously 807252T2 |
| MerCruiser | 357 STROKER SCORPION | 4-Stroke | 1G481121 & Up | 8M0109441 | Previously 807252T2 |
| MerCruiser | 383 Mag Bravo 4V | 4-Stroke | 1G480748 & Up | 8M0109441 | Previously 807252T2 |
| MerCruiser | 383 MAG STROKER INBOARD | 4-Stroke | 1G300000 & Up | 8M0109441 | Previously 807252T2 |
Technical Specs
- Product Type
- Thermostat
- Temperature Rating
- 160°F (71°C)
- Installation
- Direct replacement, standard tools
- Fuel Type
- Compatible with all fuel types
- Connection
- Standard MerCruiser configuration
- Housing Color
- Silver/Metallic
- Operating Temperature
- 160°F (71°C) opening temperature
- Warranty
- Standard manufacturer warranty
- Other Technical Attributes
- Manufactured to OEM specifications, produced in ISO9002 certified factory
What’s in the Box
- 1 x Thermostat (8M0109441)
Installation Notes
- Ensure the engine is completely cool before beginning.
- Drain the engine coolant into a suitable container.
- Locate the thermostat housing on the engine, typically where the main coolant hose connects.
- Loosen the hose clamp and carefully detach the coolant hose from the housing.
- Remove the bolts securing the thermostat housing cover.
- Note the orientation of the old thermostat before removing it and its gasket.
- Thoroughly clean the mating surfaces of the housing and its cover, removing all old gasket material.
- Install the new thermostat in the same orientation as the original. Place the new gasket into position.
- Re-secure the housing cover and tighten the bolts to the manufacturer's recommended torque.
- Reconnect the coolant hose and tighten the clamp.
- Refill the cooling system with the appropriate coolant.
- Start the engine, check for leaks, and allow it to reach operating temperature to ensure the thermostat opens correctly.
Troubleshooting & FAQ
How do I know if this 160°F thermostat is right for my engine?
This 160°F (71°C) thermostat is specified for most standard-cooled MerCruiser V6 and V8 engines made from 1987 to the present. Always consult your engine’s service manual or check the part number stamped on your existing thermostat to confirm the required temperature rating. Using the wrong temperature can affect engine performance and efficiency.
What are common signs of a failing thermostat?
A thermostat can fail in two ways: stuck open or stuck closed. If it's stuck open, your engine will take a long time to warm up or may run too cool, leading to poor fuel economy and increased engine wear. If it's stuck closed, the engine will overheat quickly, which can cause severe damage. Watch for unusual temperature gauge readings or alarms.
Is a new gasket included with this thermostat?
This package contains only the thermostat. The required gasket is sold separately. It is critical to use a new gasket during installation to ensure a proper, leak-free seal.
How often should a marine thermostat be replaced?
Thermostats don't have a fixed replacement interval, but it's good practice to inspect them annually and consider replacement every 3-5 years, especially if operating in saltwater. It is a relatively inexpensive part that can prevent catastrophic engine damage.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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