Sierra Exhaust Hose 18-2781, Replaces 3852742, 4 Inch I.D., Fits 5.0L-8.2L Marine Engines

The Sierra 18-2781 Exhaust Hose is a 4 inch inside diameter marine exhaust hose designed as a direct replacement for engine exhaust system service. It is built to move exhaust and cooling water discharge away from the engine through the boat's exhaust manifold and riser assembly, and it is engineered to meet or exceed the quality of the original equipment part it replaces. The hose carries a white finish and is sized specifically for a 4 inch I.D. Connection.

This exhaust hose is designated for a broad range of marine engines, including 5.0L, 5.7L, 5.8L, 7.4L, 8.1L, and 8.2L configurations across FL, GL, GI, GXI, GIL, GXIL, OSI, OSXI, FSI, and GSI variants. It directly replaces OEM part number 3852742, making it a straightforward drop-in solution for engines originally fitted with that hose. Whether servicing a routine exhaust hose replacement or repairing a cracked or deteriorated section, the Sierra 18-2781 restores proper exhaust routing and helps maintain a secure, leak-free connection at the manifold or riser fitting.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-2781
• Product Type: Exhaust Hose
• Inside Diameter: 4 inches
• Weight: 0.9 pounds
• Color: White
• OEM Cross Reference: 3852742
• Engine Fitment: 5.0L FL, GL, GXI, OSI; 5.7L GL, GI, GXI, GIL, GXIL, OSI, OSXI; 5.8L FL, FSI; 7.4L GL, GI, GSI; 8.1L; 8.2L GL, GSI

Fitment

• 5.0L FL, GL, GXI, OSI
• 5.7L GL, GI, GXI, GIL, GXIL, OSI, OSXI
• 5.8L FL, FSI
• 7.4L GL, GI, GSI
• 8.1L
• 8.2L GL, GSI

Replaces (OEM)

• 3852742

Frequently Asked Questions

What does the Sierra 18-2781 exhaust hose replace? The Sierra 18-2781 exhaust hose directly replaces OEM part number 3852742.

What is the inside diameter of this exhaust hose? The Sierra 18-2781 has a 4 inch inside diameter.

Which engines is the 18-2781 exhaust hose designed for? It is designated for 5.0L FL, GL, GXI, OSI; 5.7L GL, GI, GXI, GIL, GXIL, OSI, OSXI; 5.8L FL, FSI; 7.4L GL, GI, GSI; 8.1L; and 8.2L GL, GSI engine configurations.

How much does the 18-2781 exhaust hose weigh? The Sierra 18-2781 exhaust hose weighs 0.9 pounds.

What color is the Sierra 18-2781 exhaust hose? This exhaust hose has a white finish.

Is the Sierra 18-2781 a genuine OEM part or an aftermarket replacement? The 18-2781 is a Sierra aftermarket replacement hose, manufactured to meet or exceed the quality of the original equipment part it replaces, OEM number 3852742.

Will this hose fit my 5.7L GXI engine? Yes, the Sierra 18-2781 is designated for 5.7L GL, GI, GXI, GIL, GXIL, OSI, and OSXI engine configurations.

Does the 18-2781 fit 8.1L engines? Yes, the 18-2781 exhaust hose is designated for 8.1L engines, along with 8.2L GL and GSI configurations.

What comes with the Sierra 18-2781? The Sierra 18-2781 is supplied as a single exhaust hose.

Is the 18-2781 the correct hose for a 7.4L GSI engine? Yes, the Sierra 18-2781 exhaust hose is designated for 7.4L GL, GI, and GSI engine configurations.

What OEM number should I cross-reference to confirm fit for the 18-2781? Cross-reference OEM number 3852742 to confirm the Sierra 18-2781 is the correct exhaust hose for your engine.