Why Do Engines Fail?

Image of the interior of an engine. Engine failure is a preventable problem.

After spending roughly ten years as an automotive technician and almost two decades as a vehicle inspector, I have seen my fair share of engine failures. On average, I will inspect six to seven cars a week that have some sort of engine problem, ranging from issues that could be fixed relatively easily to catastrophic failures. In this post, we will concentrate on engine failures that will require the engine to be replaced. Recently I asked three other vehicle inspectors about what they typically see in the field in regards to the most common causes of engine failure. This is what we inspectors see several times a week.



This is one of the most common failures that we come across. When we go into a repair facility to inspect a vehicle that has an engine issue, one of the first things that we check is the cooling system. Specifically, we check the coolant level and for any signs of leaks. Usually, when we look at an overheated engine, the event that started the failure can be traced back to low coolant levels, a faulty water pump, or a leaking radiator (or one of its hoses). In addition, a defective thermostat and inoperative cooling system fan can cause an engine to overheat.

This is one of the reasons why it is so important to keep an eye on the temperature gauge. It’s important to know what’s normal for your vehicle. For instance, if the temperature gauge on your car is normally right below the halfway point, any deviation is a good clue that something is amiss. Also, periodically checking your parking area for any signs of leakage would be a good idea too.

Lack of Maintenance

This is pretty self explanatory. Not keeping up with the manufacturer’s recommended service intervals will hasten the demise of an engine. All car companies provide recommended maintenance schedules to their customers. Failure to follow these guidelines can be detrimental to the health of your engine. Most professional technicians that I know will change their oil and filter a little before the recommended mileage or date. For instance, if the service interval says the next oil change is due in 7500 miles, he or she may change the oil at 5500 or 6500 miles. Changing the oil and filter on a regular basis is a relatively inexpensive way to help keep your engine mechanically sound.

Lack of Lubrication

Oil pump failures are not as common as they used to be, but they still happen. This could be an oil pump that is simply not producing the flow that is needed to properly lubricate the moving parts of the engine, or a pressure relief valve that is stuck in the open position. Both of these conditions will cause lower than normal oil pressure. Conversely, if the pressure relief valve is stuck in the closed position, engine oil pressure can rise and eventually cause engine damage. Since the pump pulls the oil from the sump, we have to remember that the oil coming into the oil pump has not been filtered by the oil filter. This is another reason to change your oil on a regular basis.

Image of a leaking oil pump, which can led to engine failure

Another form of lack of lubrication is lower than normal engine oil levels. Oil that is lower than normal may not properly lubricate areas of the engine that rely on a steady supply of oil to operate correctly. In addition, the lower level of oil has to work harder to remove deposits, acids and other contaminants that are present under normal engine operation. The correct amount of oil is also important because it helps remove heat that is produced during each combustion event.

Since a good number of modern cars will have low oil level indicators or sensors that will alert the driver when the oil level is too low, this isn’t as big of a deal as it used to be. For peace of mind, though, I would recommend manually checking the oil level. If the engine does not have a dipstick you will have to follow the manufacturer’s instructions regarding proper ways to check the oil.

As a precaution I would also recommend that you or another person check the engine oil level after getting your vehicle serviced. Over the years I have repeatedly inspected engine failures that were due to the technician or lube specialists not adding the correct amount of oil to the engine after the service was completed.

Wrong Oil and Sub-Par Filters

From time to time a fellow motorist will ask me if they have to get their oil changed at a dealership. My answer is always no, you do not have to go a dealer for an oil change, but you need to make sure the repair facility that you choose uses the correct oil and a good, quality filter.

In my work as a vehicle inspector, I have routinely witnessed manufacturers and service contract providers deny claims because the owner or the repair facility used the wrong type of oil and/or an inadequate filter.

Whenever this particular topic comes up, my advice is to follow the manufacturer’s instructions and recommended service intervals. As an example, my wife’s car is still under the factory warranty. Even though I change the oil myself, I always purchase the oil and filter from the dealership. The added peace of mind is well worth the extra $10 or $15. This is important if there is a future problem that requires proving the vehicle has been properly maintained.


When we see abuse in the field, it is usually due to the engine being operated at higher than normal speeds. When I say “speed”, I am referring to the engine’s revolutions per minute. With high engine speed typically comes high engine loads. In simple terms, the “load” is how hard the engine is working at a particular moment. Higher loads mean the engine is working harder, which in turn produces higher combustion pressures and temperatures. The higher combustion pressures and temperatures also make the cooling system work harder because the additional heat is being transferred to the coolant. Driving a vehicle for a long period of time while the engine is a under a high load can cause premature engine wear.

Other examples would be driving the vehicle in an aggressive way before the engine reaches normal operating temperature, constantly doing “jackrabbit starts” and “lugging” the engine (usually seen in manual transmissions).

Bad Designs or Flawed Materials

Let’s face it, sometimes an engine design or the materials that are used in the construction of the engine are not up to par. This is probably a little more common than most would think. For example, some engines are more prone to sludge build up than others. I have often conducted vehicle inspections in which the customer had records of all of their oil changes, but still experienced pre-mature engine failure due to excessive sludge buildup.

A Water Pump With A Damaged Impeller Caused The Engine To Overheat.

We have also seen engines fail due to “material” failures of a particular part or component. This will usually be somewhat of a “pattern” failure. Meaning, the same part will fail (for multiple vehicles) right around the same mileage.  If the problem is wide spread enough, the manufacturer will usually issue a technician service bulletin or recall.

Detonation and Pre-Ignition

Detonation and pre-ignition can damage an engine from the inside out. Sometimes known as knocking or pinging, detonation is the spontaneous combustion (not burning in a uniform fashion) of the air and fuel mixture in the cylinder after the spark plug fires. When this happens, there is a sharp rise in pressure and heat in the cylinder. This heat and pressure change puts a tremendous amount of stress on the piston crowns, piston rings, ring lands, head gasket, etc.

Pre-ignition occurs when the air and fuel mixture prematurely ignites because of a hot spot in the cylinder. This hot spot causes the air and fuel to ignite before the spark plug fires. Once the spark plug does fire, the rest of the air and fuel mixture ignites, which, like detonation, causes a tremendous amount of pressure in the cylinder.

Detonation can be caused by the wrong octane fuel, high engine operating temperatures, lean air to fuel ratios, over advanced timing, inoperative exhaust gas recirculation systems and excessive carbon build-up in the cylinder. In addition, if the vehicle is turbo charged, too much boost pressure can cause detonation. Pre-ignition, on the other hand, is caused by anything that can cause a hot spot in the cylinder. This would include incandescent carbon deposits, spark plugs that are not properly fastened, the wrong spark plugs (incorrect heat range), exhaust valves that are too hot, etc.


We didn’t save this topic for last because it is the least prevalent. Believe it or not, the engine can simply fail due to a part being fatigued. From what we see in the field, this is a relatively common failure. Basically, a particular component will no longer meet a design specification or can no longer operate as the manufacturer intended. The repetitive motion of an engine’s internal components can eventually cause a part to wear out over time. Sometimes a failure is isolated to a particular part or area. Unfortunately, one failed part can in turn cause collateral damage to other components.

As you can see there are several things that can cause an engine to fail prematurely. If you have any questions or concerns regarding the health of your engine, our ASE certified inspectors are here to help.

Six Crucial Battery Functions You Didn’t Know About

Car battery with cables

Most people think of a car battery only as the thing that starts their vehicle. Of course, the battery’s main purpose is to reliably start the vehicle under a variety of operating conditions, but a car battery does much more than that. Let’s take a closer look.

  1. Preserving the life of the alternator: The battery must be able to accept a charge from the alternator. In other words, the battery must be able to “recover” its voltage (usually around 12.6 volts) after the engine starts. If there’s a problem with the battery’s chemistry or its internal components, it may not be able to accept a charge from the alternator. This reduces voltage recovery and limits the battery’s ability to start the car. However, a battery’s ability to accept a charge from the alternator also affects the health and functioning of the alternator itself. If the internal resistance of the battery changes too much, it can cause the alternator to work too hard, thus reducing its overall life expectancy.
  2. Filling in for the alternator: The battery must provide power when the alternator isn’t the main source of energy. When the engine is running, the alternator is the electrical supply source for the vehicle. When the engine isn’t running, however, the battery itself must serve as the main power source. This is why sitting in your car for too long while running the lights or the radio—even with the engine off— can kill your battery.
  3. Data preservation: When the vehicle is not running, the battery supplies current to the microprocessors (or computer modules) that are constantly working behind the scenes. These microprocessors gather data that supports computer memory for the engine and transmission control modules, among other things. All of this data—including data for less important functions like radio presets and seat position memory—can be lost in the event of a main power failure, and the battery helps to prevent this.
  4. Electrical equilibrium: The battery acts as a kind of electrical filter, helping to manage amperage levels that can range from milliamps to brief spikes of hundreds of amps. In addition, voltage spikes can occur when certain components cycle on and off, so the battery must help absorb these spikes to prevent both damage to, and interference with, vital electrical components.
  5. Guiding the charging system: In newer vehicles, the alternator output is usually controlled by the power-train or engine control module. The module in charge of regulating or controlling charging voltage uses data gathered from the battery and other sensors to strategically adjust charging voltage. This helps to prevent over- or under-charging, and increases fuel economy by reducing the alternator duty cycle when the electrical demand is lower.
  6. Acting as a supplemental power source: The alternator can become overwhelmed when electrical demand surpasses the alternator’s electrical output capacity, usually due to simultaneous use of multiple high-current consumers.

For example, if you’re driving in snowy conditions, you might be using your fog lights, rear defroster, blower motor, and windshield wipers at the same time, all while running the vehicle at lower speeds, which can put major stress on the alternator. Installation of high-current consuming aftermarket audio equipment—such as amplifiers and subwoofers—can cause similar problems.

In these situations, the battery must be recruited as an extra power source. Even then, both the life of the battery and the alternator can be significantly shortened if the vehicle operates under these conditions for extended periods.

As you can see, the humble battery is more than just a glorified “on” switch; it plays a central role in many aspects of a vehicle’s intricate electrical system. Having your battery (and alternator) checked regularly, and being mindful of how you are using them, can help prevent larger issues in the future. Thinking it might be time to give your battery a checkup? Contact us today to schedule your inspection.

How’s Your Engine Really Running?

Image of the interior of an engine. Engine failure is a preventable problem.

From time to time I will get into a conversation with a fellow motorist about how well their vehicle is or isn’t working. More specifically, these conversations are usually about how the engine is operating. One such conversation recently caught my attention. A nice lady that I met at a dealership told me that she knew her car was running well. I respectfully asked, “how do you know?” She replied, “because the check engine light is not on.”

To be honest I couldn’t fault her logic. In most drivers’ minds, if the check engine or service engine soon lights are not on, then there is not a problem. As someone in the industry, I know that it is not that simple.

My Experience with Fuel Efficiency

I drive a 2000 Honda Accord that my wife and I bought new. As a vehicle inspector, most of my days are spent going to dealerships and repair facilities all over Central North Carolina and Southern Virginia. With the amount of time that I spend on the road, it’s relatively easy for me to rack up the miles on my vehicle. There are currently over 1,000,000 miles on my car.

Photo of my odometer. Checking the odometer is critical to tracking fuel efficiency.

Even with my experience, I have no idea if my engine and its ancillary components are behaving like Honda’s engineers intended unless I connect some sort of diagnostic equipment to the vehicle. Having access to this equipment makes it easy for me to get a snapshot of the current condition of my engine and its management system.

On average, I fill up three to four times a week, so it’s easy to understand why I am big on making sure my engine and fuel management systems are running at an optimal level. I usually do an engine performance check on my car about once every other month, just to make sure everything is operating as it should be. Of course, this would be overkill for the average driver. Since I have access to the equipment, though, it’s relatively easy for me to check my car for any performance or fuel efficiency issues.

Gas Mileage is Critical

Fuel gauge indicator. Fuel efficiency is a key indicator of engine performance.

As I mentioned earlier, gas mileage per tank of fuel is really important to me. My Accord consistently gets between 440 and 460 miles out of a 15 gallon tank. That’s basically around 30 miles per gallon.  When my fuel mileage drops under 440 miles per tank, I can usually trace the excessive fuel consumption back to the way I was driving, the topography, climate, etc. If the fuel efficiency drop is even more noticeable, I will take a closer to look to see if there is anything out of the ordinary going on.


The last two times my fuel economy dropped drastically, the culprits were mis-calibrated and lazy oxygen sensors, and a failing torque converter. The torque converter had an effect of roughly twenty five miles per tank, while the oxygen sensors decreased fuel efficiency by closer to thirty miles per tank of fuel. The oxygen sensors were relatively easy to fix, while the torque converter was considerably more expensive.

Why Engine Problems Aren’t Always Obvious

Most drivers may not be aware of a problem until there are obvious issues like a lack of power, sluggishness, higher than normal fuel consumption, or the dreaded check engine light that we mentioned earlier. Making it even more challenging, many newer cars are able to cover up and mask certain issues if a sensor, actuator or other component is approaching the lower or upper boundaries of their operating parameters. Said another way, modern vehicles are so good at compensating for problems with engine management system components that a change in idle quality and engine performance may not be easily noticeable.

By the way, most technicians will not check for potential engine performance problems unless the customer brings it to their attention. The free inspection that most repair facilities offer is a usually a visual inspection of the vehicle’s undercarriage, tires, engine compartment, etc.

Now, Back to the infamous check engine light. Most people may be thinking, “why would I bother if the check engine light is not on or there are no noticeable performance issues?”

Let’s take a closer look.

The Logic Behind the Light

Just because a warning light is not illuminated doesn’t mean everything is copacetic. Without making this post too technical, we need to understand why the check engine light is activated in the first place. The main reason that the engine’s computer decides to turn on the check engine light is for a real or perceived increase in engine related emissions. In simple terms, all manufacturers want the air coming into the engine to mix with the correct amount of fuel and efficiently burn that air/fuel mixture. When this happens, the exhaust makeup will be mainly water, carbon dioxide, and small amounts of oxygen, carbon monoxide and unburned fuel. The catalytic converter is in place to reduce the harmful emissions (carbon monoxide, unburned fuel, oxides of nitrogen) even further. If a sensor, actuator or other engine management system component is not working as the manufacturer intended, then the air and fuel mixture will not burn completely and emissions levels will increase.  In this scenario, engine performance and fuel efficiency can also suffer.

An Ounce of Prevention

Depending on how much a person drives, the mileage and the age of the vehicle, my advice to motorists would be to have your vehicle checked out at least once or twice a year. For example, this could be when the vehicle is brought in for routine maintenance or, right before a road trip. As I mentioned earlier, a technician will typically not check for performance or fuel efficiency issues unless it is mentioned by the customer. Also, keep an eye on how many miles you typically go between having to refuel. Know what is “normal” for your vehicle. If there is a noticeable drop in fuel economy, then this is a good indicator that a closer look at the engine management system would be in order.

Taking these basic steps before you see a dreaded check engine light on your dashboard can help prevent seeing the light at all, and extend the life of your investment.

If you have concerns about your fuel efficiency or engine performance, contact me so we can discuss how I can help.

Happy driving!

Battery Failure: Six Reasons Why Your Car Won’t Start

Image of jumper cables attached to a battery

Several times a month, we get calls regarding vehicles that will not start. The symptoms range from a clicking noise when cranking to an engine that makes no sounds at all. The driver usually explains that the problem seems to have come from out of nowhere, or that their car won’t crank after several days of inactivity. There are several possible root causes of this problem, all of which relate to the vehicle’s battery.

Abnormal voltage levels

Infrequent use or overcharging causes abnormal voltage levels, which can make it much harder for a car battery to function properly. When a technician receives a repair request for a vehicle that won’t start, usually the first task is to test the battery’s state of charge. Normal battery voltage should be around 12.6 volts. Any voltage reading under 12.5 volts will raise an eyebrow, and a voltage reading significantly higher than 12.6 volts may indicate the charging system is overcharging the battery.

A recently-driven vehicle’s battery voltage might be a little higher due to what’s called a surface charge, which can cause a reading that is a couple tenths of a volt above normal. However, if the voltage is noticeably above that, it indicates a potential problem with the charging system.

A battery can also experience a certain degree of “self-discharge,” which means that it isn’t recharged frequently enough and will eventually lose some of its stored energy. Battery age can reduce the “standby” length prior to a failure to start. If the vehicle hasn’t been driven for four or five days, you can expect the voltage readings to be low. Voltage loss will be determined by the number of components the battery is supplying power to, its age and internal condition, ambient temperature, and how long the vehicle has been sitting. However, a charger at the correct setting can usually bring the battery back to life. 

Deep discharging and over-consumption 

Deep discharging, which happens when the state of charge is below 10.5 volts for an extended period of time, usually causes sulfating, or the accumulation and growth of lead sulfate crystals on the battery plates.  In simplistic terms, if a battery stays in a discharged state for too long any crystals that have formed under normal operating conditions will eventually combine to form larger crystals, which makes recharging even more difficult. Severe crystal formation eventually leads to a reduction of negative and positive plate capacity, which will one day lead to battery failure.

In addition, when your engine is off, the battery must provide all the necessary energy to power auxiliary functions such as interior lights, audio equipment, windows, door locks, etc. Leaving these components running for too long can deplete the battery’s state of charge and send you scrambling for your roadside assistance card.

Corrosion On Battery Terminals

Intense environmental conditions

Climate significantly affects battery life. In the Southeast, battery life averages three to four years, but in some areas of the country—including parts of the Midwest and Northeast—a battery may last for over five years.

In other words, increased exposure to excessive heat or cold (especially heat) reduces the life expectancy of a battery by increasing the intensity of what’s referred to as thermal cycling. The plates in the battery expand slightly when exposed to heat and contract slightly when exposed to colder temperatures. Over hundreds of cycles, this can warp the battery plates.

Extremely hot climates reduces battery life even further, to an average life expectancy of (approx.) 30 months. It’s especially important to keep track of your battery’s age in such climates. Battery failure is often unpredictable under these conditions.

Improper battery placement

If a battery is not secured properly in its housing (for example, due to a loose or missing hold-down clamp), the excessive movement and vibration that it is subjected to can cause the material on the battery plates to flake off, compromising the battery’s ability to function properly.

Water loss

Battery failure is frequently caused by loss of the water required to maintain normal discharging and recharging functions. In fact, water loss due to high ambient temperatures, hotter under-hood conditions, poor maintenance, and overcharging causes a good number of battery failures each year.

Poor connections

Corrosion and oxidation of battery posts and terminals can be a big problem. The gasses that escape the battery case when recharging is a major contributor to corrosion and acid formation. Dissimilar metals (battery posts, terminals and copper wiring) can also accelerate corrosion and acid build up. Corrosion is a poor conductor of electricity, because it increases circuit resistance, which in turn can have an effect on starting and charging.

This list isn’t exhaustive, of course. There are many other causes of battery failure, and some batteries are simply faulty, failing well before the end of their warranty despite proper care. However, the vast majority of the time, you can get the maximum value out of your battery’s life by taking some common-sense precautions to protect it from environmental, electrical, and physical damage. If you’re concerned about the condition of your battery, contact us to schedule an inspection.

Ten Questions to Ask Your Repair Shop

Ten Questions to Ask Your Repair Shop

Finding a good shop is complicated and time consuming enough, but how do you make sure you’re getting quality service from the shop you’ve chosen?

If you keep these 10 questions in mind, you’ll be well on your way to understanding exactly what you’re getting from your service provider.

  1. How long have you been in business? If a repair shop has been around for a while, it’s a good indication that they may be on the more reputable side. It also means they are likely to have an established review history online, so check them out on ratings websites like Google, Yelp, and the Better Business Bureau.
  2. What car lines do you specialize in? With the sophistication of today’s automobiles, trying to repair each and every car line can be a daunting task. In our experience, garages that specialize in one or two different manufacturers seem to be a little more conversant and efficient.
  3. What are your qualifications? Ask about the shop’s affiliations with automotive repair organizations and active ASE certification for technicians. You should also figure out if there are any master certified or “A” technicians on staff who are qualified to diagnose and repair a problem without any assistance from other shop personnel.
  4. Who will be working on my vehicle? Some shops will have their “A” technician diagnose the customer’s concern and then assign the actual repair procedure to a less experienced team member. In most cases there is nothing wrong with this practice, but it becomes more important as the skill level needed to diagnose or complete a particular job increases. Remember, as a customer, you have the right to know who will be doing the repairs on your vehicle.
  5. What kind of parts do you use? Ask if they use factory or aftermarket parts, and inquire as to whether they give customers a choice. This can be tricky; aftermarket parts are usually less expensive, but they are often more limited in terms of reliability and warranty coverage.
  6. Is your repair facility well equipped? Figure out if they have all the tools that you would expect a modern repair facility to have. Do they use professional-level tools and diagnostic equipment?
  7. What is your labor rate? This is self-explanatory. Labor rates vary from shop to shop. The highest is not necessarily the best. Again, do your research.
  8. Are you willing to work with my extended warranty? If you own an extended warranty, make sure your shop is willing to work with the extended warranty company. This is important because warranty companies typically pay labor at a reduced rate and will sometimes provide the repair facility with used or re-manufactured parts. Your shop may not be willing to do that transmission job that normally pays 10 hours of labor for the seven hours the extended warranty company is offering.
  9. What labor guide do you use? A labor guide is what a repair facility uses to determine how much labor time it takes to complete a particular repair. These time guides do not factor in unforeseen issues, like seized or rusty fasteners, broken bolts, etc. Consumers need to know if the shop uses the manufacturer’s time guide or that of an aftermarket provider like Alldata, Mitchell, or Chilton’s, since these times will vary.
  10. Are your technicians required to take continuing education training classes? At the rate that technology is being integrated into today’s cars, additional training is vital. Repair facility owners, managers, and technicians who invest in periodic training demonstrate a solid level of commitment to their field.

It goes without saying that looking for an automotive maintenance and service provider that you’ll be comfortable with can be a daunting task. Hopefully, these suggestions will make it a little easier to ensure your service and repair provider meets your needs.