Boat 101: Boat Smoke and Lubricating Oil

Last updated on October 13th, 2017 at 12:29 pm

When it comes to the condition of motorboats, one of the best ways to determine current or potential problems is by observing the boat smoke and lubricating oil.

First up, exhaust gases from marine engines should be clear. Any color of smoke can warn you of potential trouble. Below are possible smoke discolorations you may find:

Black Smoke – This means that there are particles exiting the exhaust that are not completely burned. Possible reasons are insufficient air intake, engine overload and in the case of diesel engines, a fuel injector failure.

White Smoke –It can be a result of possible air in the fuel can, dirty fuel containing water vapor, or an atomized fuel with water. The atomized fuel appears like fog and is a result of starting a cold engine.

Blue Smoke – This smoke is formed when the combustion engine burns the lubricating oil creating a carbon accumulation. Damaged valve guides, oil seals or piston rings can cause the oil slip. For diesel engines, the oil can be a result of an overspill from the crankcase or an overfilled air filter.

Next, the level of lubricating oil in your boat engine should be checked habitually. The oil condition can also pinpoint a possible problem in the engine. Ideally, it should be checked every day before you start the boat. A good practice on checking the oil is to feel the deep stick for any unwanted particles. These particles can determine if there is any contamination. Lightly rub the oil on the stick using your thumb and index finger and feel the consistency of the oil. It should feel as smooth as possible. After you are done, don’t forget to clean the oil on your fingers using a paper towel.

For weekend boaters who don’t fire up their boats regularly, check on your engine oil level. The tendency is for it to be too high or too low. If the oil level is too high, it means that the oil sump has been penetrated by water. You can check by looking at the oil. If it looks milky, then it has water on it. This problem might lead to breaking of a piston or cracking of the cylinder head.

Both can happen at the same time too.

On the other hand, if the oil level is too low, it might be indicative of an oil leakage. Try to check if there is any oil trace in the bilge. Most of the time, water is touching the oil pan for marine engines because they are placed in the bilge. Bilge is the bottom part of a boat that is always underwater. After a few years, the bilge can have holes due to corrosion and can cause water to reach the oil pan.

Always check for the boat smoke and lubrication oil to make sure that your boat is in best condition. Whenever there is a large deviation from normal, take that as an urgent warning. Start looking for more clues or seek the advice of an expert.

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