Thermostat Housing Gasket – Fits MerCruiser GM 4-Cylinder, V6 & V8 Engines (Replaces 27-33179Q02)
Thermostat Housing Gasket – Fits MerCruiser GM 4-Cylinder, V6 & V8 Engines (Replaces 27-33179Q02) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Thermostat Housing Gasket – Fits MerCruiser GM 4-Cylinder, V6 &...
Product Details
This high-quality Thermostat Housing Gasket – Fits MerCruiser GM 4-Cylinder, V6 & V8 Engines is designed for a precise fit on MerCruiser (MCM/MIE) GM 4-cylinder, V6, and V8 engines that utilize a flat cover plate thermostat housing.
It serves as a direct cross-reference for Mercury/MerCruiser OEM part number 27-33179Q02, ensuring proper fit and function.
- Ensures a reliable, leak-free seal for the thermostat housing.
- Installs directly in place of the original factory gasket with no modifications required.
- Designed for marine environments to withstand heat and corrosion.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket brands.
| Brand | Part Number | Notes |
|---|---|---|
| Mercury / MerCruiser | 27-33179Q02 | For thermostat housing with flat cover plate |
Engine & Model Compatibility
Confirm your engine model and year in the table below.
For MerCruiser models, this gasket is compatible with GM-based 4-cylinder, V6, and V8 engines that have a flat cover plate thermostat housing. Please verify your housing type before ordering.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| MerCruiser | GM 4-cylinder engines | 27-33179Q02 | For thermostat housing with flat cover plate | |||
| MerCruiser | GM V6 engines | 27-33179Q02 | For thermostat housing with flat cover plate | |||
| MerCruiser | GM V8 engines | 27-33179Q02 | For thermostat housing with flat cover plate |
Technical Specs
- Product Type
- Thermostat Housing Gasket
- Application
- MCM/MIE GM 4-cylinder, V6 and V8 engines with flat cover plate thermostat housing
- Replaces OEM Part Number
- 27-33179Q02
- Dimensions
- 6.0 × 7.5 × 1.06 inches
- Weight
- 0.07 lb (0.032 kg)
- UPC
- 745061597846
What’s in the Box
- 1 x Thermostat Housing Gasket (27-33179Q02)
Installation Notes
- Ensure the engine is completely cool before beginning work.
- Drain the engine coolant to a level below the thermostat housing.
- Remove the bolts securing the thermostat housing cover.
- Carefully remove the old gasket and any remaining residue. Clean both mating surfaces until they are smooth and free of debris.
- Place the new gasket onto the housing, ensuring it aligns perfectly with the bolt holes.
- Reinstall the housing cover and tighten the bolts to the manufacturer-specified torque in a crisscross pattern.
- Refill the cooling system with the correct type and amount of coolant.
- Start the engine and carefully check for any leaks around the housing as the engine reaches operating temperature.
Troubleshooting & FAQ
How do I know if this gasket fits my engine?
This gasket is for MerCruiser MCM/MIE engines based on GM 4-cylinder, V6, and V8 blocks, but only those with a flat cover plate thermostat housing. Always visually compare your old gasket and housing design to our product images to confirm fitment.
What are the signs of a failed thermostat housing gasket?
The most common signs are visible coolant leaks around the thermostat housing, unexplained engine overheating, or a constantly low coolant level without an obvious external leak.
Do I need to use sealant with this gasket?
This gasket is designed to be installed dry. Applying sealant is generally not recommended unless explicitly required by your engine's service manual for your specific application or to repair minor surface imperfections.
How often should the thermostat gasket be replaced?
It is best practice to replace the thermostat housing gasket whenever you replace the thermostat or otherwise service the cooling system. There is no fixed replacement interval, but you should inspect it for leaks during routine maintenance.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9001 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 and specifications against 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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