Exhaust Elbow Gasket – Fits MerCruiser 3.7L (Replaces Mercury Marine 27-18272)
Exhaust Elbow Gasket – Fits MerCruiser 3.7L (Replaces Mercury Marine 27-18272) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Exhaust Elbow Gasket – Fits MerCruiser 3.7L (Replaces Mercury Marin...
Product Details
This Exhaust Elbow Gasket is designed for MerCruiser 3.7L L4 engines with aluminum exhaust manifolds, specifically covering models from 1985–1989. It ensures a proper seal between the exhaust elbow/reservoir and the exhaust manifold to prevent leaks.
This part directly replaces Sierra 18-0881, GLM 32470, and Mercury Marine parts 27-97863 and 27-18272.
- Installs between the exhaust elbow/reservoir and the exhaust manifold.
- Constructed from a durable Graphoil/Tin Composite that is more tear-resistant than many alternatives.
- Features a special "anti-stick" coating for easier removal during future service.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Notes |
|---|---|---|
| Mercury Marine | 27-18272 | |
| Mercury Marine | 27-97863 | Superseded by 27-18272 |
| Sierra | 18-0881 | |
| GLM | 32470 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This gasket is for specific MerCruiser engines using aluminum exhaust manifolds. Please check your serial number range and manifold type to ensure correct fitment.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| MerCruiser | 165 3.7L | 165 HP | L4 | 1987 | 27-18272 | |
| MerCruiser | 170 3.7L | 170 HP | L4 | 1985–1986 | 27-18272 | |
| MerCruiser | 180 3.7L/LX | 180 HP | L4 | 1987 | 27-18272 | |
| MerCruiser | 190 3.7L | 190 HP | L4 | 1985–1986 | 27-18272 | |
| MerCruiser | 3.7L | L4 | 1988–1989 | 27-18272 | ||
| MerCruiser | 3.7LX | L4 | 1988–1989 | 27-18272 | ||
| MerCruiser | 470 | L4 | 1983–1984 | 27-18272 | ||
| MerCruiser | 485 | L4 | 1980–1982 | 27-18272 | Supersedes 27-97863 | |
| MerCruiser | 488 | L4 | 1983–1984 | 27-18272 | Supersedes 27-97863 |
Technical Specs
- Product Type
- Exhaust Elbow Gasket
- Installation
- Between exhaust elbow/reservoir and exhaust manifold
- Housing Material
- Graphoil/Tin Composite
- Dimensions
- 18.0" L x 14.0" W x 1.0" H
- Warranty
- 2 years (Hardin Marine); 3 years (GLM Marine)
- Other Technical Attributes
- More tear resistant than OEM and other aftermarket competitors; features "anti-stick" coating for easy removal.
What’s in the Box
- 1 x GASKET (27-18272)
Installation Notes
- Ensure the engine is completely cool and the battery is disconnected before starting work.
- Drain the engine coolant to a level below the exhaust manifold to prevent spills.
- Carefully detach the exhaust elbow or reservoir from the manifold by removing its mounting bolts.
- Thoroughly clean both mating surfaces. Use a gasket scraper to remove all traces of the old gasket and any corrosion, ensuring the surfaces are smooth and flat.
- Position the new gasket correctly over the mounting studs or bolt holes. Confirm it is not installed upside down or backward.
- Re-attach the exhaust elbow or reservoir. Hand-tighten the bolts first, then torque them to the manufacturer's specifications in the recommended sequence.
- Refill the cooling system, then start the engine and carefully check for any exhaust or coolant leaks around the new gasket.
Troubleshooting & FAQ
How do I confirm this gasket fits my specific MerCruiser engine?
This gasket is for 3.7L L4 engines from 1985–1989 with aluminum exhaust manifolds. The best way to confirm fitment is to check your engine's part manual or cross-reference the OEM part number (27-18272 or 27-97863) with the number on your old gasket.
What makes this graphoil/tin gasket different from other types?
The graphoil and tin composite construction offers superior tear resistance and durability compared to some OEM and aftermarket paper-based gaskets. It also features an "anti-stick" coating, which simplifies removal during future maintenance without leaving behind hard-to-clean residue.
What are the signs of a failing exhaust elbow gasket?
Common signs of failure include water leaking externally from the joint between the manifold and elbow, water entering the cylinders (which can cause catastrophic engine damage), engine overheating, or an audible exhaust leak (a hissing or ticking sound) in that area.
Is there a recommended replacement interval for this gasket?
There is no fixed replacement interval for this gasket. It should be replaced whenever the exhaust elbow is removed for service, or immediately if signs of a leak are detected.
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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