21246119 By-Pass Valve | Genuine Volvo Penta Part

🔧 Product Description

A coolant bypass valve used in the water-pump and thermostat-housing circuit on a broad selection of Volvo Penta D13 marine engines. It controls internal coolant circulation while the main thermostat changes position.

🚤 Compatibility

• Engine Family: D

Full model list at the end of this description.

⚙️ Key Features

• Controls coolant bypass flow
• Supports even engine warm-up
• Works with the specified thermostat and housing seals
• Direct replacement where part number 21246119 is specified
• Engine type: D13 inline-six turbocharged marine diesel

🔌 Function

Regulates coolant bypass flow during warm-up and thermostat operation.

⚠️ Common Signs of Failure

• Engine warms too slowly
• Localised overheating
• Unstable coolant temperature
• Valve stuck open or closed
• Coolant-flow noise or restricted circulation

🛠️ Service Notes

• Note the orientation and the port connections before removal; a bypass valve fitted the wrong way round will not regulate at all
• These are set assemblies rather than adjustable parts — renew the valve rather than attempting to alter its setting
• Check the seat and bore in the housing for debris, scoring and wear and clean the passages; grit holding a valve part-open is a common fault
• Renew the seals, O-rings or sealing washers and tighten to the figures in the workshop manual for your engine
• Run up afterwards and confirm normal system pressure or temperature behaviour, and investigate the cause if the old valve had failed open

🔄 Supersession & Cross Reference

OEM / Related Numbers

• 3889622 - thermostat housing
• 18813 - gasket
• 946086 - plug
• 949659 - O-ring
• 21412639 - thermostat

📦 Condition

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

🔎 Full Model Compatibility

Typically suits:

• Volvo Penta D13C2-B MP, D13C1-A MP, D13C2-A MP, D13C3-A MP, D13C4-A MP, D13B-A MP, D13B-H MP, D13B-G MP, D13B-L MP, D13B-E MG, D13B-E MG (FE), D13B-E MH, D13B-E MH (FE), D13B-F MG, D13B-F MG (FE), D13B-K MP, D13B-N MH, D13B-N MH (FE), D13B-B MP, D13B-D MP, D13B-J MP, D13B-M MP, D13B-C MP, D13C4-B MP, D13C5-B MP, D13C6-A MP, D13C1-A MH, D13C2-A MH, D13C1-B MG, D13C3-B MG, D13C5-A MP, D13C2-A MG, D13C1-A MG, D13C7-B MP, D13C8-B MP, D13C9-A MP