Tips to prolong engine life and reduce operating costs
By Nick Johnson
Protecting your investment is essential to your bottom line. Safeguarding your engine with preventative maintenance will reduce your total ownership and operating cost, increase uptime, and provide the maximum engine life available. The entire engine life is directly associated with your bottom line and total operating cost. This article should help you achieve the most life of your engines and the components within those engines.
Fluids are the lifeblood of any engine. Coolant protects against heat, freezing, corrosion and cavitation. The engine oil lubricates, cools & cleans components. Fuel allows for combustion but also acts like a lubricant, coolant and cleaner for the fuel system. Diesel Exhaust Fluid (DEF), while it isn’t an engine fluid, is part of the fluid system on U.S. EPA Tier 4 Final engines and any on-highway truck engine built after 2012. DEF quality plays a big part in uptime on newer engines and like any fluid, it should be treated with care to keep it clean. We will talk about DEF when we talk about aftertreatment in another segment.
Read this article with all images in the digital issue of Engine Professional magazine https://engineprofessional.com/2024EPQ2/#p=44
Let’s start with coolant, seems like a straightforward fluid, right? Not so fast, it’s critically important to the life of the engine. Not only does the coolant protect the engine against overheating and freezing, but it also protects vital cooling components from corrosion & cavitation. Coolant must be checked for proper glycol levels to ensure its freeze protection; generally, 50/50 coolant is good for about -35°F (-37°C). Coolant also allows for a higher boiling point which is important at higher coolant temperatures, it’s not uncommon to see pockets of coolant that are above the boiling point of water. The coolant provides corrosion protection to all the different types of metals (brass, copper, iron, aluminum, stainless steel) within the cooling system as well as plastics and rubber found in the cooling system. The coolant must play nicely with all those dissimilar materials.
Cooling system cavitation is also a huge concern, especially on cylinder liners. The cyclic expansion and contraction of the cylinder liners and the vibrations around a liner create a perfect storm for cavitation. If cavitation is bad enough it can cause liners to leak coolant into the crankcase or into the cylinder bore. At this point to repair the engine, you’re completely disassembling it and might as well just rebuild it. Using Cat Extended Life Coolant (ELC) will reduce the chances of cooling system cavitation. There is no need for coolant additives while using Cat ELC other than one recharge at 6000 hours. One other issue that can cause liner/coolant issues is the grounding of electrical systems or electrolysis. Never use any of the cooling components as a ground. Stray current will damage the cooling system with electrolysis. Finally, let’s talk about the water used within your coolants. Ideally you just buy the 50/50 pre-mix and dump it in. If that is not an option be sure to use distilled water when you mix with coolant. Tap water will lead to clogging of coolers with deposits, generally made up of calcium and lime. Never use raw water unless it’s an absolute emergency. Once you get somewhere to flush the raw water out, do so, and refill with Cat ELC and distilled water.
Engine oil tends to get people all wrapped around the axle. You’ve probably seen the “what oil do you use” question on every forum for anything with an engine. Here is my stance on oil, run a quality oil, use the weight suggested by the manufacturer with the correct API rating. If it’s a diesel, use oils for diesels engines. If it’s a gasser, use oil blended for engines burning gaseous fuels. Pretty simple! There is ZERO need for any exotic oils in a factory, stock engine.
In the nearly 20 years at Caterpillar, I’ve never seen a true oil-related failure. What I mean by that is the oil failed and caused the engine/component to fail. Here’s the deal, oils do not fail. There’s always an outside source like fuel or water dilution, high oil temps, extended drain intervals, excessive loads etc etc. Scheduled Oil Sampling (SOS) will help you track those outside sources; it will also help you trend oil changes. Believe in the technology of SOS, it could save you 50% or more on your oil changes by creating the correct hour interval. Yes, changing oil is great, but you can change it too often and then it’s just a waste of money and resources. Remember, lubricants and preventative maintenance are the second highest expense of owning an engine, fuel being the first.
Speaking of fuel let’s jump into it. There used to be an old saying around Caterpillar, it was on magnets and all sorts of goodies when I first started at Caterpillar… It said, “Keep ‘em Clean, Keep ‘em Running, Keep ‘em Customers.” That still holds true today. Common rail fuel systems are producing almost 40,000psi, any debris or water in the fuel is game over for pumps and injectors. This isn’t 1974 anymore, you need to have clean, dry fuel. We must think of the fuel cleanliness from the time we dispense it into the tank back to when it was refined into diesel fuel.
Every touchpoint of the fuel as it’s moved from storage vessel to storage vessel is a place to introduce contamination. The closer fuel gets to being dispensed into the engine tank, the higher the likelihood of contaminated fuel. Therefore, we recommend that fuel be filtered as it leaves one tank and is filtered as it enters the next. For example, you buy fuel in bulk, and it’s delivered by a semi. The fuel should be filtered as it is pumped into the tanker trailer and then filtered again as it leaves the tanker trailer into your storage tanks. From your storage tanks to other storage tanks or the final dispensing point should be filtered as well. Finally, don’t overlook the dispenser and the fuel tank fill, keep them clean and debris-free.
Ok, so we’ve got fluids out of the way. So, let’s switch gears to filters. Filters are extremely important to the overall life of the engine, they protect the air system from microscopic pieces of dust, remove water in fuel and oil filters keep contamination levels low in oils. A great old saying for parts also fits for filters, “good parts ain’t cheap, and cheap parts ain’t good.” The better the filter, the more protection. Cat has several levels of filtration offered from standard filtration up to our Ultra High Efficiency (UHE) filters. So, what’s the most important filter on the engine, the air filter, fuel or lube filters? Well, they’re all important but the air filter is the most important to the total life of the engine. Dirty air will wear out turbo compressor wheels, intake valve faces and valve seats, piston rings and polish cylinder bores. Then, all that dirt ends up either in the oil pan or going through the exhaust valves and seats as well as the turbine wheel of the turbo.
Blow by will cause some of that dirt past the rings and cylinder wall of the engine and end up right in the oil. If we keep the dirt out of the intake tract and the cylinders, we also reduce the debris load on the oil filter. Oil filters already have a tough job, now you just made it that much more difficult after we added dirt. Quality oil filters are very important, they must keep the system clean for 250 – 1000 hours. Keep the hard particulate out of your bearings and you’ll see greater life.
We spoke about fuel above so let’s hit those fuel filters. As I mentioned common rail systems today have very high pressure, upwards of 40,000psi. Without good filtration there is no way fuel system components can make it to a full life. Fuel filters don’t just filter the fuel, they also help remove any water that may have entered the fuel system. Fuel-water separators are what remove water from fuel. Generally, we run a fuel-water separator and then a secondary filter which is much tighter than the fuel-water separator. Fuel systems today have clearances smaller than 3micron, at that size you must have a good secondary filter. Our filters are more efficient, have a higher water removal capacity, and lower micron levels than many other filters. Many other filters may thread onto our filter bases but they cannot filter to the level that our filters can. This is how we can achieve longer fuel system life, we can get the dirt and water out! One last thing that irks me to no end is the filling of fuel filters before installation. This is the number one place that dirt is introduced DIRECTLY to the injectors. Remember, when you fill that filter, it’s going into the clean side.
OK. Let’s shift over to operational indicators. You might ask, what’s an operational indicator? These are things that tip us off when there could be a problem. These operational indicators come before the big bang, or when the engine gives up the ghost. Some examples of operational indicators would be excessive smoke (no aftertreatment), high fuel or oil consumption, unusual noises like knocking or clattering, fluid leaks, lack of power, hard starting when cold or hot, high crankcase pressure, and so on. Running engines with these indicators present will cause engine damage. You need to stop and get the engine sorted out before it’s damaged. All those operational indicators lead us to an area where we need to focus on the engine. Excessive smoke could mean worn piston rings or valve guide seals, improper injection timing or bad fuel injectors. Knocking could be a bad rod bearing or an injector firing out of time. A leaking water pump could cause the engine to overheat and damage the pistons. High crankcase pressure could indicate bad piston rings, a clogged breather tube, broken piston, or other issues. If you have any of these operational indicators, stop running the engine! It will cost less for the repair, and you won’t do as much damage to your engine if you stop it before the big bang! Repairing before failure is always more cost-effective to fix than repairing an engine after it goes bang.
Some other times you should stop the engine is if there are any indicator lamps. These may be a check engine light, service for the emissions equipment, low oil level, low oil pressure, high temperature, low coolant level and so on. Running an engine with service lamps present can cause major damage to your engine. Now while a low oil pressure lamp may be more serious than a check engine light, the reason for the check engine light could eventually cause as much damage as a low oil pressure indicator. Again, repair before failure is always more economical than repairing an engine that went bang.
Finally, a few other maintenance items that should not be overlooked. One of these items is valve lash. This should not be overlooked, even if “it never changes.” Incorrect valve lash causes many issues but the biggest one is catastrophic valve/engine failure. An exhaust valve with too little lash can hang open and cause compression loss and will most likely burn up the valve. That same valve with too much lash could break the valve off at the stem, this is caused by the rocker arm smacking the valve and allowing the valve to slam closed versus closing gently while following the ramp of the camshaft.
Another thing to consider is following the correct service procedures. Today’s engines are very complex requiring many different types of service. A few that come to mind are one-time use fuel lines for common rail systems, correct engine and aftertreatment software, specific trim files for Cat Injectors, replacing torque to yield hardware for critical joints, and aftertreatment specific maintenance. Following the correct service procedures for these items, and others not listed, will increase total engine life, and will also give you a more productive engine. It will also ensure better fuel economy and emissions performance.
Ok, so you’ve followed until the end, good! How do you feel about all the information you just received? Are you overwhelmed, anxious, or nervous? Do you wonder how good your maintenance has been up to now? Maybe you feel good about your current maintenance, but you think you need better filters? These are things that your Cat dealer can provide with Customer Value Agreements (CVAs). CVAs come in all sorts of different packages. You could be very basic and only want filters, but you want them at a flat cost and included in your monthly payment for the machine. That’s something we offer in a Filters and Fluids CVA. Maybe you want complete maintenance and extra coverage, With a Performance CVA that is what you get. Complete maintenance and extended coverage for fuel injectors, turbos, and aftertreatment. These are just a couple of CVA examples. There are CVA’s for multiple segments that Caterpillar serves, just reach out to your local Cat dealer to learn more.
I hope this article helped you learn something, and also helps you protect your investment. These practices do not just apply to Cat engines, they can apply to any engine brand, engine type and engine application. Following the recommendations in this document will ensure you get the most life from your engine. Longer engine life equates to lower cost per hour and ensures more profit for your business.
Read this article with all images in the digital issue of Engine Professional magazine https://engineprofessional.com/2024EPQ2/#p=44