Thermostat Gasket – Fits MerCruiser GM V6 & V8 Engines (27-53045Q01)
Thermostat Gasket – Fits MerCruiser GM V6 & V8 Engines (27-53045Q01) is backordered and will ship as soon as it is back in stock.
Couldn't load pickup availability
Worry-free returns
Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Thermostat Gasket – Fits MerCruiser GM V6 & V8 Engines (27-5304...
Product Details
This Thermostat Gasket – Fits MerCruiser GM V6 & V8 Engines (27-53045Q01) is designed as a direct replacement for the thermostat housing on MerCruiser GM V6 (4.3L) and V8 (5.0L, 5.7L) engines. It creates a reliable seal to prevent coolant leaks and helps maintain proper engine operating temperature for optimal performance.
It serves as a direct interchange for Mercury/Quicksilver part numbers 27-53045Q01 and 27-53045, and is also equivalent to aftermarket references from Sierra (18-2841), Yongfe (27-53045Q01), and SQnFeG (27-53045Q01).
- Installs as a direct replacement for the original gasket.
- Made from durable paper/composite material to ensure a secure, long-lasting seal.
- Engineered for use in marine gasoline engine applications.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket brands.
| Brand | Part Number | Notes |
|---|---|---|
| Mercury/Quicksilver | 27-53045 | Original part number. |
| Mercury/Quicksilver | 27-53045Q01 | Supersedes 27-53045. |
| Sierra | 18-2841 | Aftermarket equivalent. |
| Yongfe | 27-53045Q01 | Aftermarket equivalent. |
| SQnFeG | 27-53045Q01 | Aftermarket equivalent. |
Engine & Model Compatibility
Confirm your engine model and year in the table below. This part is primarily for MerCruiser GM engines.
For MerCruiser Engines: This gasket is intended for the standard cooling systems on select GM-based V6 and V8 models. Please verify your specific engine serial number or original part requirement.
| Brand | Model | Rated HP | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|---|
| MerCruiser | GM V6 | 4.3L | 4-Stroke | 27-53045Q01 | Gasket for standard cooling system |
| MerCruiser | GM V8 | 5.0L | 4-Stroke | 27-53045Q01 | Gasket for standard cooling system |
| MerCruiser | GM V8 | 5.7L | 4-Stroke | 27-53045Q01 | Gasket for standard cooling system |
Technical Specs
- Product Type
- Thermostat Housing Gasket
- Installation
- Direct replacement
- Fuel Type
- Gasoline
- Housing Material
- Paper/Composite
- Product Dimensions
- 11.5 cm x 11.5 cm x 0.2 cm
- Weight
- 0.05 kg (1.76 ounces)
What’s in the Box
- 1 x Thermostat Gasket (27-53045Q01)
Installation Notes
- Disconnect the boat's battery before beginning work.
- Drain the engine coolant to a level below the thermostat housing.
- Locate the thermostat housing and carefully remove the mounting bolts.
- Gently pry the housing loose and remove the old gasket.
- Thoroughly clean both mating surfaces, ensuring they are free of old gasket material and debris.
- Position the new gasket correctly on the engine block or housing.
- Reinstall the thermostat housing and tighten the bolts evenly to the manufacturer's recommended torque specification.
- Refill the cooling system with the appropriate coolant.
- Reconnect the battery, start the engine, and carefully check for any leaks around the housing as the engine warms up.
Troubleshooting & FAQ
How do I know if this gasket fits my engine?
This gasket is made for specific MerCruiser GM V6 (4.3L) and V8 (5.0L, 5.7L) engines. The best way to ensure compatibility is to cross-reference your engine's original part number with 27-53045Q01 or one of the listed aftermarket equivalents. Always compare the gasket's shape to your old part before installation.
What are the signs of a failed thermostat gasket?
Common signs include visible coolant leaks or residue around the thermostat housing, engine overheating, or erratic temperature gauge readings. A damaged gasket compromises the cooling system's seal, leading to coolant loss and inefficient temperature regulation.
When should I replace my thermostat gasket?
It is best practice to replace the thermostat gasket every time the thermostat itself is replaced. You should also install a new one if you notice any leaks or damage during routine engine inspections.
What is the difference between OEM and aftermarket parts?
This listing is an aftermarket replacement (not OEM). It has been built to OEM-level specifications with comparable materials. Our parts are manufactured in an ISO 9002 facility and are batch-inspected for consistency and quality.
What are the shipping speed and cost?
We ship worldwide quickly—typical transit time is 5–15 days. Standard shipping is free to most locations; expedited options will appear at checkout where available.
What is the warranty and return policy?
This part is covered by a 1-year warranty against manufacturing defects under normal marine use. If you encounter any issues, please contact our support team with your order details. Returns are accepted within our standard window for items that are unused and in their original condition. See our policy page or reach out for instructions.
Safety & Important Info
- Verify images and specifications against your original part before purchase. If anything differs—even if your model appears compatible—do not install the part.
- This is an aftermarket replacement component, not an original equipment manufacturer (OEM) part.
- Professional installation is highly recommended for safety and optimal performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and rigorously tested for real-world conditions.
- Fast Global Fulfillment — We offer free standard delivery to most regions, with an average transit time of 5–15 days.
- Manufacturer-Direct Value — Our parts deliver fair pricing without compromising on materials or quality control.
Payment & Security
Payment methods
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
