Volvo Penta D4 (300-hp)
The Volvo Penta D4 diesel engine models range from 225-hp to 300-hp and therefore have many applications in both single and twin configurations. Our video gives a detailed look at some of the important components bolted onto the block and we give the recommended maintenance schedules for checking and replacement.
Major Components in the Volvo Penta D4--The air filter should be replaced every 200 hours and is easy to access as shown here. The compressor (just above the alternator) with its spring loaded tensioner is how the D4 gets its outstanding acceleration. It will disengage at cruising speed and rely solely on the turbo. Oil level should be checked every 200 hours and must be changed every 800 hours or every five years… whichever comes first. Below the compressor is the belt driven 115 AMP alternator. The turbo charger is driven by exhaust gasses and further compresses air that has been filtered and already compressed by the supercharger. The charge air cooler takes the compressed air from the turbo and cools it, which forces the air molecules even closer together, thus getting even more oxygen into the combustion chamber for more power and lower emissions. It has sacrificial anodes that should be replaced every 200 hours or 12 months. This is the EVC (Electronic Vessel Control) system which communicates with the display at the panel to show engine status and alarms. A mechanical pump brings fuel from the tank first to the fuel filter/water separator which should be changed every 200 hours or 1 year. When the fuel filter/water separator is changed the unit will have to be bled which is done by connecting a clear hose to the nipple Capt. Steve is pointing out with this finger. Fuel is then pumped through the system with the rubber pump button (red arrow) until it is free of air bubbles. We have taken the top off of the crankcase ventilation filter to show what it looks like inside. It needs to be inspected for possible replacement every 200 hours. The arrows indicate the two idler pulleys. They help with tension and keep vibration down. There are two screw-off lids on the integral raw water filter. The second one is made of clear plastic; the filter can be inspected with the engine operating. With both tops off of we can see the plastic filter which can easily be lifted out by hand and cleaned. Most boats will also have a raw water sea strainer near the thru-hull intake.Capt. Steve has his left hand on the engine oil and by-pass filters which Volvo Penta recommends be changed every 50 to 200 hours, depending on how the engine is used.