Houseboating and Engine Oil Analysis 

     Very few automobile engines on today’s highways encounter the sustained wear and high RPM’s that a marine four stroke engine does.  Let’s face it, as Houseboater’s we think nothing of starting our boats and running down the lake or river for hours on end at 3000 RPM or higher.  I’ll bet that the last time you drove to the lake at 65 MPH your car probably never exceeded 2500 RPM on the entire trip.  In looking at the way we operate our boats it becomes apparent that our four stroke engines see the potential for extreme operating conditions and wear.  The one element that protects us from this extreme wear is the quality and volume of the lubrication fluids inside our engines.  Like the human heart,  the engine oil pump circulates the life giving fluid (oil) throughout the engine making sure all parts are lubricated and friction free.   After all …what causes engine wear ?  FRICTION !

      Without the success of  this important function and fluids our engines would be subjected to high temperatures and high friction causing the moving engine parts to wear excessively. This can ultimately lead to catastrophic engine failure or very high maintenance and repair costs. 

     Now that we have determined the importance of engine oil, let’s look at what professional analysis of oil can tell us about the internal working parts of the engine. The expected results can be very much like a blood test at your physician’s office.  By analyzing your blood a doctor can tell you if you have, high cholesterol, Diabetes, kidney or liver dysfunction, Hepatitis , AIDS or many other ailments.  A comprehensive engine oil analysis can tell you much the same information about your engines. 

     Spectrographic Engine Oil Analysis by a qualified laboratory can tell us many things about our engines and the condition of the working parts of the engine. It is typically conducted to determine the overall fitness and condition of the lubricant and engine components. Analysis of the levels and types of contaminates found in the oil can be used to determine which of the engine components are wearing and if the wear is becoming critical. In many cases this has made the difference between an overhaul and complete engine replacement. 

     The most serious types of  engine oil contaminates are dirt, coolant and fuel. Fuel dilution is really serious business because it will reduce the viscosity of the lubricant and cause excessive engine wear . In some cases fuel dilution can be detectable by smelling the oil on the engine oil dip stick. There is a noticeable difference between the smell of oil and the smell of gasoline.  Typical ways that fuel gets into oil are by engine flooding and cracked cylinder walls in the engine. 

     Coolant is the most common and probably the most serious type of contamination.  The water reduces the lubrication properties of the oil and causes metal corrosion while the glycol breaks down at high temperatures and causes a sludge build up in the engine. Typical ways to get water into the oil are through cracked heads and blown gaskets that are undetectable to the naked eye. 

     Dirt   is probably the most common engine contaminant. High levels can lead to excessive engine wear…that’s why the engine manufacturer places filters on the oil, air and fuel.  Typical ways for dirt to get into a marine engine is through contaminated fuel, missing  oil caps, loose dip sticks , defective valve cover gaskets, defective PCV valves and defective air cleaners. 

     Other “wear metal” elements typically found in engine oil and the part failure indicators are as follows: 

• Boron - oil additives or anti-freeze additives

• Zinc/phosphorous/calcium/magnesium/barium -  oil additives

• Iron – cylinders, liners, pistons, rings, valves, valve guides, bearings, gears, shafts, rust.

• Aluminum – pistons, bearings, turbo chargers, pump vanes, thrust washers

• Chromium -  compression rings, anti-friction bearings, shafts, coolant additives

• Copper – bearings, bushings, thrust washers, valve guides, injector shields, wet clutches

• Lead – bearings,  gear oil additives, fuel additives

• Tin – bearings

• Silver – anti friction bearings, silver solder, wrist pin bushings

• Silicon – sand, dirt, anti foam oil additive, gasket sealant material, antifreeze additive

     These contaminants are measured in PPM or “parts per million” relative to the sample  of oil provided to the laboratory. The engine oil sample is drawn from the engine by a trained technician and sent to a qualified laboratory for analysis using ASTM (American Society for Testing Materials) guidelines or military specifications. A lab report is usually provided within three to seven days and will give detailed analysis of the elements found and possible indicators of excessive wear. 

     Periodic engine oil analysis was originally used a tool to detect diesel and gasoline  engine problems on large earth moving equipment before they became serious and expensive.  Its value has just recently been recognized as a tool to analyze the condition and internal parts of the inboard engine on  large recreational boats. Typical cost of engine oil analysis ranges from $20 per sample to $65 per sample depending on the laboratory costs and the analysis that is performed.    

     Should you desire to have your engine oil analyzed you should contact a qualified Marine Surveyor or qualified Marine Mechanic. They can either draw the sample for the laboratory or steer you in the right direction to someone who can. To truly understand what’s going on below the rear deck hatch, I recommend engine oil analysis be done before any seasonal oil changes or during a marine pre-purchase survey.  It’s better to be safe than sorry ! 

Kevin DeWitt- Surveyor Associate
Please contact me at 1.859.420.7659 to arrange for a survey of your vessel.