A Blood Test for Your Trucks

Your engine’s oil is the equivalent of your blood.  When your doctor wants to know what is going on inside you he doesn’t head you straight to the surgery.  She likely starts with taking a couple of tubes of blood and sends it off to a lab for tests based on what she has observed.  Showing early signs of diabetes – there’s a test for that.  Concerned about cholesterol and potentially blocked arteries?  Again, there is a relatively simple test that will show if further investigation is required.

The same thing is available for your truck’s engines.  Antifreeze in the oil is a major cause of serious repairs and engine failures.  There are many ways that antifreeze can get into the oil – failing seals, pin holes in liners or in the oil cooler among others.  By the time the oil is visibly discolored the situation has probably gone beyond the point of a simple and relatively economical repair.  A second major cause is fuel getting into the oil and diluting it or washing it off surfaces.  A bad injector or a damaged duel pump can cause fuel to leak into the oil pan and reduce the oil’s effectiveness.  Just as leaving an increased level of cholesterol could shorten your lifespan, ignoring any contaminants in the oil could result in a much shorter life for your truck’s engine.

When to start?

So when should you start an oil analysis program?  In short, right from the first oil change.  This gives you a baseline to compare future test results against.  By doing testing right from the start and then at every drain you will see when problems start – not just dealing with them when the truck is at the side of the road and waiting for a wrecker.  Beyond avoiding an on the road breakdown, there are a few other reasons you will want to do oil analysis on every drain.

Why to use oil testing?

The first reason is to determine if you are on the proper drain interval.  Many of us use the same mileage interval for all engines.  Without doing testing you may be losing an opportunity for an extending the distance between oil changes.  Alternatively, you may find that a specific run of engines requires a shorter interval to maintain peak performance.  Different manufacturers use slightly different metal alloys for their blocks, heads, etc., resulting in slightly different wear patterns.  In addition, different filter manufacturers may have a stronger solution for certain engines as opposed to others.  Brand A may be better for a Cummins while Brand B is superior on a Volvo and a Detroit may be best off with an OEM filter.  A similar discussion can be had with brands and types of oil.  Again, one engine may perform best with brand A’s conventional oil while another wants brand B’s semi-synthetic to get its best performance.  Your parts procurement department my just be focusing on price or single sourcing – both worthy goals – but without having some data that an oil analysis can uncover you may be increasing your total cost of ownership of certain equipment.  By paying a few dollars more for a filter or by dealing with an additional vendor or two you could find that you are able to extend you drain interval from 25,000 miles to 27,500 miles – an additional 10%.  If the truck is kept for around 600,000 miles, this means 2.5 fewer oil changes over it’s lifespan – a savings of between $500 and $1000 per truck over the time you own it.  This is only the lowest hanging fruit.

A more valuable return is in the detection of any contaminants in the oil – fuel, anti freeze, metal, etc.  Here you need to work with your lab to determine what is the correct level for an alert to be shown.  For example, many experts believe that even a trace amount of anti-freeze in the oil is too much and should trigger further investigation.  In terms of fuel dilution, the trend may be more important than just it’s mere presence.  The level of cleanliness of the oil and its trend should act as a trigger, especially if it is getting worse.  This could point to a change in operating conditions that may warrant a shorter drain interval or it cold point to a bad batch of filters.  The amount of metal in the oil is an item that both the quantity and the trend are important. Seeing an increasing amount should trigger an investigation into where it is coming from and what steps can be taken to prevent an over the road failure.  At the same time, comparing the amount to other engines of the same make/model and similar mileage could point towards a component that wears out more rapidly than with other engines.  Having that knowledge can allow you to create an additional maintenance point for those engines to either replace that part before they fail or at a minimum create an inspection program to monitor that item.

The reports you get back from the lab need to be reviewed, not just filed away in a cabinet.  At a minimum your maintenance manager needs to be looking at them for any alerts that the testing company.  Ideally, they are looking at the results against the last report to identify any items that are trending the wrong way.  Any of these items should result in a vetting program being triggered as they may or may not signify that a condition exists.  What should be put in motion is a further series of diagnostics that could include during a further, more intensive oil test as well as doing a more general computer diagnostic of the engine to look for any indications of a condition.  While we are discussing it, connecting your vehicles to a diagnostic computer at each preventative maintenance service is also a best practice as the data download will add to your predictive analysis toolkit!

An ROI on avoiding breakdowns is much more subjective, but here are a few costs that come with a breakdown:

  • An unhappy and unproductive driver. You are going to have to pay for layovers, motel rooms and meals at a minimum each time a major failure happens on the road.
  • You will likely be paying more for an outside shop to do the repairs. At a minimum you have likely required the services of a tow truck to bring your vehicle into a repair facility – a cost that could have been avoided
  • The per day cost of just owning that vehicle (payments, depreciation, licenses and permits, etc.) for the days that it is sitting there not generating any revenue.
  • Unless you can use a repair facility that you either already have an account with or that you can use a nation account, you are going to need to pay for the repair once it has been completed instead of having a 30-day (or greater) payment term. On a large repair the implicit financing costs could be significant, in addition to the costs of issuing a T or Com Check or using up credit card limit space.
  • Potentially the cost of a replacement vehicle if the repair can not be made in a timely manner due to shop capacity, availability of parts, etc. This again is a preventable expense.
  • The cost of a service failure to your customer, either in the load waiting for the vehicle to get repaired before delivering the load or the use of out of route miles to send another driver in to recover the load.

Best practices

Here are a few best practices that the Noria Corporation recommend for oil testing:

  1. More frequent testing and inspection. In short, do it every oil change.  Infrequent testing makes it much more difficult to catch faults and root causes before they become failures.
  2. More comprehensive examinations. Cutting back oil testing (both in terms of quantity and quality) can be a false economy.  It’s only by using a wide enough net that you can capture enough data to guide your techs towards areas that need attention.  This applies to all areas of condition monitoring.  The exact amount of monitoring may be different from company to company but spend the time to determine what works for you based on some of the failures that you have encountered in the past.
  3. Pin-drop sensitive alarms and limits. Keeping in mind that with regular testing an alarm should be considered just a trigger for further monitoring, having more alarms because of tighter limits is a good thing.  This puts your staff in the habit of looking for warning signs during an inspection instead of just reacting.
  4. Be wary of too few reportable conditions. Noria finds that on average 30% or oil reports should have some sort of reportable condition and not less than 10% (unless you are looking at very new vehicles).  Alerts do not mean your maintenance team are failing.  On the contrary they are a way to encourage continuous improvement.  Finally, they allow your shop to focus its efforts on items that provide the most uptime for the lowest cost.

Oil analysis is both a form of insurance as well as another diagnostic tool that you can use to predict failures before they happen and correct them during scheduled downtime instead of a on the road emergency.  Just as you would not send a mechanic to do all repairs with a hammer, think of this as an additional source of information that will guide your shop to use its resources more wisely, reduce overall ownership costs and be more efficient.

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