MerCruiser Thermostat for Cummins CMD QSD 2.8L & 4.2L, 80°C (176°F) – Replaces 8M0093561
MerCruiser Thermostat for Cummins CMD QSD 2.8L & 4.2L, 80°C (176°F) – Replaces 8M0093561 is backordered and will ship as soon as it is back in stock.
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MerCruiser Thermostat for Cummins CMD QSD 2.8L & 4.2L, 80°C (17...
MerCruiser Thermostat for Cummins CMD QSD 2.8L & 4.2L, 80°C (176°F) – Replaces 8M0093561 is backordered and will ship as soon as it is back in stock.
Product Details
This replacement thermostat is designed for MerCruiser and Cummins MerCruiser Diesel (CMD) QSD 2.8L and 4.2L marine engines. It helps regulate coolant flow so the engine can maintain its specified operating temperature.
The thermostat is calibrated for an opening temperature of 80°C (176°F). It is supplied as one thermostat for installation in the engine cooling system.
Use the reference numbers below to compare this replacement with the thermostat currently installed on your engine.
- Application: MerCruiser Stern / Out Drive cooling systems
- Engine families: Cummins MerCruiser Diesel CMD QSD 2.8L and 4.2L
- Opening temperature: 80°C (176°F)
- Product format: Single thermostat, not a multi-component kit
OEM Reference Numbers
The following MerCruiser reference numbers are associated with this thermostat application:
| Brand | Reference Number | Application Note |
|---|---|---|
| MerCruiser | 8M0093561 | Primary reference |
| MerCruiser | 879194215 | Reference number |
| MerCruiser | 879194233 | Reference number |
| MerCruiser | 879194231 | Reference number |
| MerCruiser | 896332148 | Reference number |
Engine Compatibility
This thermostat is listed for Cummins MerCruiser Diesel CMD QSD engine applications with the following displacements:
| Engine Brand | Engine Family | Displacement | Thermostat Temperature | Reference Numbers |
|---|---|---|---|---|
| MerCruiser / CMD | QSD | 2.8L | 80°C (176°F) | 8M0093561, 879194215, 879194233, 879194231, 896332148 |
| MerCruiser / CMD | QSD | 4.2L | 80°C (176°F) | 8M0093561, 879194215, 879194233, 879194231, 896332148 |
Confirm the complete engine model, serial information, housing configuration, and the reference number on your existing thermostat before ordering. Displacement alone may not identify every engine variation.
Technical Specifications
- Product Type
- Thermostat
- Application
- Marine engine cooling system
- Engine Family
- Cummins MerCruiser Diesel CMD QSD
- Compatible Displacements
- 2.8L and 4.2L
- Opening Temperature
- 80°C (176°F)
- Package Format
- Single thermostat
What's in the Box
- 1 x Thermostat
Gaskets, O-rings, seals, coolant, and other installation hardware are not included unless specifically shown in the product photos or stated in the order details.
Installation Notes
- Allow the engine to cool completely before beginning work.
- Drain the engine coolant into a suitable, clean container according to the engine manufacturer's procedure.
- Locate and remove the thermostat housing. Note the orientation of the old thermostat before removal.
- Remove the old thermostat and clean the mating surfaces of the housing and engine.
- Install the replacement thermostat in the correct orientation. Use a new gasket or seal where required; replacement sealing parts are not included.
- Reinstall the housing and tighten the retaining bolts to the manufacturer's specification.
- Refill the cooling system with the correct coolant and bleed air from the system as required.
- Run the engine, check carefully for leaks, and monitor the temperature to confirm correct operation.
Troubleshooting & FAQ
How do I know if my engine's thermostat may be failing?
Possible symptoms include overheating, an engine that runs unusually cold, unstable temperature readings, poor heating performance, or coolant leakage around the thermostat housing. Diagnose the cooling system before replacing the thermostat.
What temperature does this thermostat open at?
This thermostat is specified to begin opening at 80°C (176°F).
Is a gasket included?
No. The package contains one thermostat only. A suitable new gasket or seal should be obtained separately if required for your engine.
Does this fit every QSD engine?
The listed application covers CMD QSD 2.8L and 4.2L engines. Confirm the complete model, serial information, housing configuration, and reference number before installation.
Is this an OEM component?
This listing is for a replacement thermostat associated with the MerCruiser reference numbers shown above. It is not represented as a genuine MerCruiser-branded component.
Shipping speed and cost?
Typical transit is 5–15 days. Available shipping services and costs are displayed at checkout.
Warranty and returns?
Warranty and return eligibility are governed by the applicable order and store policies. Contact support with your order details if you need assistance.
Safety & Important Information
- Verify the complete engine model, serial information, thermostat dimensions, housing configuration, and reference number before purchase.
- Do not rely on engine displacement alone when confirming compatibility.
- Always work on a completely cool engine and follow the engine manufacturer's service procedures.
- Professional installation is recommended when coolant-system service or engine-specific procedures are unfamiliar.
About Sea Sierra
- Pro-Grade Standards — We supply marine replacement parts selected for dependable service in real-world marine applications.
- Global Fulfillment — Shipping options and delivery estimates are provided at checkout.
- Manufacturer-Direct Value — Fair pricing with careful product and reference-number matching.
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