859874 Valve Seat | Genuine Volvo Penta Part

🔧 Product Description

Genuine Volvo Penta valve seat from the Engine group, weighing 0.023 kg and listed for 9 applications across the TMD, MS, TAMD and MD engine series. This listing group carries a second valve seat with the same name, the same nine applications and the same engine families, 859875, and the published information does not distinguish the two beyond their part numbers and a 2 gram difference in weight. Order by part number, taken from the parts list for your engine, rather than trying to tell them apart by description.

🚤 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

• 0.023 kg
• 9 applications across TMD, MS, TAMD and MD engines
• Engine group, cylinder head component
• Cannot be told apart from valve seat 859875 by the published details — 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

• Compression loss on one cylinder that does not improve with an oil test
• Valve clearances closing up between checks as the valve sinks into its seat
• Burnt or pitted contact band visible when the valve is lifted
• Seat recessed below the head face, or cracked between seat and port
• Hard starting and a misfire that is worst when the engine is cold

🛠️ Service Notes

• Seat renewal is a machining job — the head has to be cut and the valves ground in to match
• Check the guides at the same time; a worn guide lets the valve hammer its seat and the new seat will follow the old one
• Reset the valve clearances after the head is rebuilt

📦 Condition

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