Brand: VOLVO
Category: Marine Engines
Document Type: Manual
Language: EN
Manual for 230, 250, 251DOHC, AQ131, AQ151, AQ171
Uploaded: April 20, 2026, 7:57 p.m.
This manual provides technical data, descriptions, and repair instructions for Volvo Penta engines. It covers safety precautions, general information, repair instructions, and detailed procedures for various engine components, including the fuel system, ignition system, cylinder head, cooling system, and lubrication system. The manual emphasizes the importance of using genuine Volvo Penta parts and following recommended procedures to ensure safety and proper engine function. It also includes a troubleshooting guide and overhaul data for specific engine models.
Troubleshooting and error codes
| Engine does not start | Engine stops | Engine does not reach operating speed at full throttle | Engine runs rough or vibrates abnormally | Engine becomes abnormally hot | Fault reason |
|---|---|---|---|---|---|
| X | Main switch open. Battery discharged. Wires broken or fuse blown. | ||||
| X | X | Empty fuel tank, closed fuel cock, clogged fuel filter. | |||
| X | X | X | Water or impurities in the fuel. | ||
| X | X | Faulty spark plugs. | |||
| X | X | Burned breaker points, moisture in distributor and ignition leads. | |||
| X | X | Faulty electronic unit 251DOHC, AQ171 | |||
| X | X | Idling speed not adjusted properly. | |||
| X | Faulty tachometer. | ||||
| X | Boat loaded abnormally. | ||||
| X | Growth on boat bottom and sterndrive. | ||||
| X | Damaged propeller. | ||||
| X | Clogged cooling water intake, oil cooler (250, 251DOHC, AQ151, AQ171) waterjackets. Damaged impeller or thermostat. Too low coolant level in expansion tank | ||||
| X | X | Wrong fuel quality in relation to timing | |||
| X | X | Toothed belt faulty or not adjusted properly. |