Yacht and Boat Engine Service, Overhaul and Mobile Repair

The interval depends on the engine make, model and how the boat is used, and the manufacturer’s service schedule always comes first. As a general rule, marine diesel engine oil and oil filters are changed every 100–250 running hours. Even if the hours have not been reached, the oil should be changed at least once a year, ideally before winter lay-up, because acids and moisture in used oil cause internal corrosion while the engine sits idle.

The impeller is the most frequently worn part of the cooling system and is generally replaced once a year, at recommissioning. A cracked impeller or one with missing vanes quickly causes the engine to overheat, and broken vanes can travel to the heat exchanger and block it. That is why the heat exchanger inlet should also be checked whenever the impeller is changed.

Winterization includes changing the engine oil and filters, flushing the raw water circuit with fresh water and protecting it with antifreeze, removing the impeller to store it dry or replacing it, keeping the fuel tank full to prevent condensation, draining the fuel water separator and maintaining the batteries. These steps protect the engine against corrosion and frost damage over the winter.

Engines that sit for months commonly suffer from dried-out seals, hardened hoses, corroded electrical connections and water collected in the fuel tank. A proper check and service at recommissioning reduces the risk of breakdowns at sea and ensures full engine performance throughout the season.

Black smoke usually points to insufficient air (a clogged air filter), overloading or injector faults; blue smoke means the engine is burning oil (worn piston rings or valve stem seals); white smoke that persists after a cold start indicates water in the fuel or coolant entering the combustion chamber. Colour alone is not a definitive diagnosis, but it shows which system needs to be inspected.

Condensation causes water and sediment to build up in boat fuel tanks. The fuel water separator traps this water and debris before it reaches the injectors and fuel pump. If it is neglected, the result is power loss, rough running and expensive injector and pump failures. Water should be drained from the separator bowl regularly and the element replaced every season.

Sacrificial anodes on the engine and shaft should be checked every season and replaced when they are about half worn. Anodes corrode in place of expensive components such as the engine block, heat exchanger and propeller, protecting them from galvanic corrosion.

Oil consumption and blue smoke, low compression, noticeable power loss, excessive crankcase blow-by, knocking noises, or the engine reaching the overhaul hours specified by the manufacturer are the main signs that a major overhaul is needed. We assess the engine’s condition with a compression test and oil analysis and give you a clear report on whether an overhaul is required.

If the block and crankshaft are sound, a full overhaul usually costs considerably less than a new engine and gives the engine a long new service life. If the block is cracked, heavily corroded or would need uneconomical parts, repowering may be the better choice. After dismantling and measuring, we present both options with their costs so the decision is made together with you.

A whistling or rubbing noise from the turbo, increased exhaust smoke, power loss and oil at the turbo outlet all indicate that a turbo rebuild is needed. During the rebuild the turbo cartridge is dismantled, the journal and thrust bearings, piston rings and seals are renewed, and the shaft and wheels are inspected. A timely rebuild prevents the turbo from failing and damaging the engine.

Yes. EPS Marine provides mobile technical service on site across Turkey, in marinas, boatyards, berths and winter storage yards. Routine maintenance and breakdown repairs are carried out wherever your boat is. For overhaul and machining work that requires the engine to be removed, we lift the engine out, overhaul it in the workshop and then reinstall it.

We provide routine maintenance, fault diagnosis and repair for all widely used marine diesel engine brands, including Yanmar, Volvo Penta, MAN, IVECO and Solé Diesel. If your engine brand is not listed, please contact us.

Thanks to our broad supplier network, we quickly source both genuine and OEM-quality spare parts. We choose the parts together with you according to your needs and budget, and inform you about the parts used before the work begins.

Standard routine maintenance including oil and filter changes is completed within the same day on most boats. For major repairs and overhauls, the duration depends on the nature of the fault and parts availability, and you are informed of the timeline before work starts.

We start planning as soon as we receive your call, and our mobile service organisation across Turkey allows us to reach your boat as quickly as possible. Fast response is our priority so that a mid-season breakdown does not ruin your cruising plans.