21186281 Inlet Valve | Genuine Volvo Penta Part

🔧 Product Description

Genuine intake valve for selected Volvo Penta D2 and MD2040 marine diesel engines. Part number 21186281 replaces the earlier inlet-valve reference 3580478.

🚤 Compatibility

Typically suits:

• Volvo Penta D2-55F
• Volvo Penta D2-50F
• Volvo Penta D2-75F
• Volvo Penta D2-60F

• Engine Family: D
• HP Range: 50-75 HP

⚙️ Key Features

• Current inlet valve replacing 3580478
• Confirmed D2-55 and D2-75 applications
• Confirmed MD2040 engine-family application
• Correct valve stem, head and seat geometry
• Requires valve-seat, guide and clearance inspection during installation

🔌 Function

The inlet valve opens during the intake stroke to admit clean combustion air into the cylinder and seals against the valve seat during compression and combustion.

⚠️ Common Signs of Failure

• Rough idle or cylinder misfire
• Valve leakage during a compression or leak-down test
• Burnt, bent or recessed valve head
• Excessive valve-stem or guide wear

🛠️ Service Notes

• Keep valves in order and fit each one to the seat it is lapped to; a new valve must be lapped in until a continuous, even contact band shows right round
• Check the guide for wear before fitting a new valve — a good valve in a worn guide will not seat or seal for long
• Clean the deposits from the port and seat, wash every trace of lapping paste out of the head, and lubricate the stem with clean engine oil on assembly
• Fit new stem seals and check installed spring height and valve recess against the figures in the workshop manual for your engine
• Set the valve clearances on assembly and re-check them after the first running period, following the procedure for your engine

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 21186281 → Supersedes 3580478

OEM / Related Numbers

• 3580478 earlier number superseded by this part

📦 Condition

• Genuine Volvo Penta part
• Brand new
• Supplied in original or equivalent packaging