First, regular visual inspection will reveal any leaks, usually in the form of seepage. another thing that is typically true when real guages are present, a little under or a little over the middle is the normal range. For these reasons, air-cooler failures occur routinely. Most problems develop gradually and by monitoring temperatures, replacing zincs, and looking for visual signs of leaks, you will be able to keep your cool and maximize engine performance. In these engines, volumetric efficiency as defined by equation (3) should be used with caution to avoid misinterpretation. Some 4-stroke engines can also utilize significant scavenging flow at some operating conditions to limit the maximum exhaust gas temperature and to purge residual gases. Since automotive engines normally operate at temperatures higher than marine engines, these devices can sometimes provide inaccurate readings. Air coming into the cooler contains contaminants that will cling to the cooling vanes, while seawater will gradually cause accumulation inside the tubes. For the best answers, search on this site https://shorturl.im/axSpM. I have a Yanmar Yanmar Marine Diesel Engine Model 4JH4-HTE. (The Silverado temperatures were also compared with … Check out the Marine Diesel Maintenance & Troubleshooting Course over at Boaters University, our online education platform. A failing air cooler will reduce the engine’s efficiency, resulting in a loss of boost pressure from the turbo. 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This manual describes the procedures for proper handling and routine maintenance of: W-46 Marine Diesel Propulsion Engines To obtain best operating condition and longest service life, it is important to use it sensibly and carry out operation and maintenance according to this manual. Failing impellers release small bits of rubber into the loop and these also accumulate at the heat exchanger, impeding flow. Without a way to remove that heat, it’s a matter of time before heat buildup would lead to overheating. Operation Operating techniques outlined in this manual are basic. The average operating temperature of an engine is found by measuring the temperature of the thermostat housing with an infrared thermometer and should be between 180-200 degrees Fahrenheit. The cooling fins inside this aftercooler have become severely fouled from poor maintenance. It’s generally accepted that petroleum-based engine oil starts oxidizing (breaking down) around 240 degrees F (115 degrees Celsius), while full synthetics, such as Rotella T6, can handle temperatures above 300 degrees F. Clogs can form in the cooling hoses, heater exchangers or in the raw-water strainer, mixing elbow or muffler. (Photo credit: Seaboard Marine). How does one salvage an RV from the bottom of a lake? Typically the seawater or coolant circulation will be less than 15 PSI, while the oil will be at a much higher value, above 60 PSI. When I increase throttle the temperature drops and then increaseds again. Thermostat Functions A thermostat has two important functions which help keep an engine at its optimal temperature: 175-185. When cruising at 70% power the the water temperature (as indicated by the standard water temperature guage) increases to 220 F. This seems to high. When the temperature goes above 200, start getting worried. © 2021 Cruz Bay Publishing, Inc., an Active Interest Media company. For the coolant/seawater heat exchanger, use a pyrometer to compare the temperature of the coolant entering to the coolant leaving. You can sign in to vote the answer. After a bit of time you will have a good idea of your normal operating temp reading on the gauge and can keep an eye out for changes. They assist with developing the skills and techniques required to operate the engine more efficiently and economically. The oil then flows into the seawater loop, eventually exiting with the exhaust gasses. various diesel engine systems operating parameters available for protection and monitoring purposes; however, the extent of the instrumentation required will vary with the specific engine model and application. At the first sign of moisture or green verdigris around fittings, add this item to your to-do list. To clean tubes, circulate a descaling solution through the seawater loop, or remove the heat exchanger core and send it out for an ultra-sonic treatment. The temperature of the coolant can rise above 212F degrees because coolant is pressurized (NOT because the water is mixed with antifreeze). With fresh water or a closed cooling system, temps from 170 … The drop should be about 10 degrees Fahrenheit. Seawater inside a metal chamber can lead to galvanic corrosion (coolers that circulate coolant do not have this issue). Turbochargers operational faults, location of those faults, causes, and remedies to be taken in order to troubleshoot the improper operation of turbocharger are explained in a step by step procedure. An intercooler uses seawater to cool the air before it is ingested by the engine. The normal engine operating temperature, for a 3306 Caterpillar diesel engine, is 180 degrees. The normal operating temperature of the coolant in an engine is about 210F to 240F degrees. If you see a gradual reduction in the difference, chances are it’s time for some maintenance. A build-up of minerals, broken impeller pieces, and pencil zincs accumulate and block the flow of cooling water. As the fuel runs through the engine it picks up heat, sending warmed fuel back to the tanks. Steve Zimmerman is the president of Zimmerman Marine, which operates five boatyards in Maryland, Virginia, North Carolina and South Carolina. Using coolant instead of seawater reduces some of the maintenance issues described below. Turbochargers force more air into the engine in order to gain horsepower. What do you do if you drive a convertible and you park it but forget the roof down and it rains heavy outside while you are at your job? Once again, seawater passes through small tubes (in many cases combined with thin plates like car radiators), but in this case air circulates around the tubes. This rating is for applications operating less than 500 hours per year. The cast aluminum housing has cracked and failure is imminent. The temperature of the coolant can rise above 212F degrees because coolant is pressurized (NOT because the water is mixed with antifreeze). Diesel engines are sometimes called compression-ignition engines because initiation of combustion relies on air … Boat owners can keep an eye on their heat exchangers in several ways. The thermostat OPENS at 195F degrees; but, the temperature continues to rise to the normal operating temperature. To prevent internal corrosion, sacrificial anodes, often referred to as “pencil zincs”, fit into the chamber of the heat exchanger, sometimes two per unit. An engine consuming 15 gallons per hour might be running 60 gallons per hour through the fuel lines, sending the unused fuel back to the tank through the return line. Sailboats. Let’s start with corrosion. The engine should not be operated at temperatures above 200 degrees. For oil coolers, measure the delta between oil in and oil out of the cooler—in this case the drop should be in the 10-20 degree range. What is the average running temperature on a diesel marine engine? If your in 35 degree water, your engine is going to run about 135 degrees, 70 - 80 degree water = 170 - … That is Y your overheat light is on.If U keep running it the expense will be going up.Best get it checked out.The thermostat is what controls the engine temp not water outside temp. Saltwater flows through the many coolers and heat exchangers. From "Hands-On sailor" from our March 2007 issue. For fuel coolers you should also see a drop, but the main requirement here is that the fuel entering the engine must meet the manufacturer’s requirement. Dialing down the RPM’s may allow the engine to … The minimum starting temperature that allows starting without pre-heating is 40 °C for precombustion chamber engines, 20 °C for swirl chamber engines, and 0 °C for direct injected engines. Bad gauges are one of the most common causes of problems. Intake charge management is the process that is used to ensure that the intake charge supplied to the combustion chamber at all operating conditions meets a number of requirements including: 1. a sufficient quantity of oxygen is available to ensure complete combustion, … A bad … Echoing Saildog...as I recall salt comes out in the 140's F range, so a raw water engine operating in salt water should not exceed 140F as operating temperature. When an impeller has lost pieces of rubber, each piece must be located and removed downstream. Find out how many pencil zincs your engine contains and have ample spares of the correct sizes aboard. Smaller engines with a displacement of less than 1 litre per cylinder usually have glowplugs , whilst larger heavy-duty engines have flame-start systems . Want to learn more about Maintaining and Troubleshooting Diesel Engines? To further complicate the challenge, most air-cooler housings consist of cast aluminum, while the core usually contains copper. Building on our unique portfolio of technologies and services, we offer integrated system solutions that raise the efficiency, sustainability and profitability of the marine industries. Seawater flows inside the heat exchanger’s tubes, while the liquid to be cooled—oil or diesel fuel—circulates around the outside of the tubes. This all sounds like a science experiment: let’s mix copper, aluminum, seawater, and hot air, and see how long it lasts! How do you think about the answers? As seawater flows into the small tubes, debris can accumulate, obstructing the flow. Get your answers by asking now. In extreme cases, the hotter air entering the cylinders can lead to premature cylinder failure or ingestion of liquid into the cylinder. 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