859875 Valve Seat | Genuine Volvo Penta Part

🔧 Product Description

Genuine Volvo Penta valve seat from the Engine group, weighing 0.025 kg and listed for 9 applications across the TMD, MS, TAMD and MD engine series. It sits alongside valve seat 859874, which carries the same name, the same nine applications and the same engine families; only 2 grams separate the two and nothing else in the published detail sets them apart, so take the number from the parts list for your engine rather than judging by appearance.

🚤 Compatibility

Typically suits:

• Volvo Penta TMD22A
• Volvo Penta TMD22B
• Volvo Penta TMD22P-C
• Volvo Penta MS2B-A
• Volvo Penta TAMD22P-B
• Volvo Penta MD22
• Volvo Penta MD22A
• Volvo Penta MD22L
• Volvo Penta MD22P

• Engine Family: TMD, MS, TAMD, MD

⚙️ Key Features

• 0.025 kg
• 9 applications across TMD, MS, TAMD and MD engines
• Engine group, cylinder head component
• Not separable from valve seat 859874 on the published detail — order by number

🔌 Function

Gives the valve a hardened landing in the cylinder head, sealing the combustion chamber and carrying heat out of the valve head into the casting.

⚠️ Common Signs of Failure

• One cylinder down on compression with no improvement from an oil test
• Valve clearance shrinking between services as the seat wears deeper
• Burnt, pitted or unevenly worn contact face on the seat
• Seat sunk below the head face or cracked through to a port
• Rough idle and hard cold starting on an otherwise sound engine

🛠️ Service Notes

• Seats are cut into the head, so plan for machining rather than a bench swap
• Renew guides and stem seals at the same time if there is any stem play
• Reset the valve clearances once the head has been rebuilt and run

📦 Condition

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