mechanic looking at belly of vehicle

What’s Causing My Truck To Leak Oil (Reasons, Effects, and Fixes)?

Your handy truck is emitting a funky smell. It’ll go away, though, right? Is it time to bring it to the shop?  If you’ve ever asked or thought of any of these questions, your truck is likely showing signs of a classic oil leak. While you might want to write off the small puddle under your truck that shows signs of the “sweats,” these puddles may indicate that something more serious is happening. It could be an oil leak. And if an oil leak goes undiagnosed, serious damage can occur.

What happens when oil leaks go undiagnosed

When a truck leaks oil, the leak poses a fire, environmental, engine, and pedestrian hazard to others. It’s crucial to be mindful of the common hazards that leaks can cause. That way, you can fix it.

Oil leaks can cause fires

If an oil gasket, filter, drain plug, or pan is leaking, it could also potentially catch fire. Make sure not to use a fire extinguisher unless the vehicle is in flames. Extinguishers often cause more damage than good.

Taking the time to fix the oil leak first will ensure you save yourself money, time, and heartache in the long run both for yourself and your truck’s body and engine.

Engine damage

Oil leaks are best friends with fire. When a fire ignites, it wreaks havoc on the radiator, HVAC and cooling system, and other key elements that are made of rubber and urethane.

These items are sensitive to heat, so if a vehicle leaks oil, the oil can degrade the rubber hoses, seals, and other equipment around the vehicle’s interior.

Worse yet, if oil ignites, fires can erupt, leaving the driver with a dreadful dilemma: to repair or replace an engine (and other worn-out parts) — that is the question.

Being proactive will ensure damage doesn’t occur to your car or truck’s motor parts.

Environmental hazards

If fires weren’t enough to worry about, leaky oil plugs, filters, and pans can result in toxic substances — like lead, zinc, and arsenic — being left behind. These chemicals are housed in your engine, and leaky oil can help loosen these chemicals up from the metal components of your engine.

What results is a pool of left behind toxic substances that wash away and come into contact with animals and plants that are sensitive to toxic substances.

Danger to drivers and pedestrians

Oil leaks and smoke pose danger to people. 

A truck’s engine is one of the hottest parts of the vehicle. When the engine comes into contact with an oil slick, the likelihood of combustion increases.

That’s why it’s important to know the signs and symptoms that your truck is leaking oil. It’s easy to imagine the alternative: let’s say a truck driver is 10 hours into a 12-hour shift. They’re tired and not practicing driver safety measures. Uh-oh: they have an oil leak in their gasket.

Their truck — now a ticking time bomb — poses a real threat to those around them. The truck could combust at any moment, scaring and hurting countless children, elders, and adults.

It’s crucial every fleet manager, truck driver, and pedestrian understand the hazards, signs, and symptoms so they can take corrective and preventative measures to prevent oil leaks. 

Knowing the signs of what an oil leak looks, smells, sounds, and feels like — the topic of our next section — will help you be proactive in avoiding the hazards of a leaky vehicle, saving you time and money in fixing your trusted fleet vehicle.

Signs and symptoms that your truck is leaking oil

An oil leak from a truck often has a distinct smell, look, and sound (yes, oil leaks make noise). It’s worth being familiar with the four most common signs and symptoms that show a truck is leaking oil. Doing so will save you time and money and keep people safe.

1. Oil puddles

People often dismiss the rainbow puddle in their driveway after a rainstorm as toxic runoff. What they may not realize is that these pretty-looking pools of liquid are the result of an oil leak from under the car’s engine.

Healthy and normal-looking oil is usually black. If it’s brown, the vehicle is leaking engine oil. Duller oil is lighter, often has a milky complexion, or looks a bit bubbly or frothy. If the greasy-looking liquid coming out of your vehicle looks orange or green and smells sweet, the liquid is likely coolant.

It’s important to check the valve cover gasket and oil filter — among other car or truck parts — frequently before and after a long drive to ensure no leaks or cracks harm the vehicle. Otherwise, greater trouble could be in store for a vehicle’s foreseeable future.

2. Smoke coming out of the engine or tailpipe

Blue smoke is another tell-tale sign of an oil leak or serious damage to a truck’s internal components. If blue smoke emits from either the hood or the tailpipe, the smoke emitted could be the result of burning oil from either the valve cover or valve cover gasket, oil pan, or camshaft and crankshaft seals. If ingested for long periods, drivers will become light-headed as a result of inhaling toxic fumes.

If you see smoke coming from your car, both inside and outside, stop driving. Consult your local mechanic and use a local in-shop or mobile repair service immediately, as smoke can be a symptom of a larger problem, such as a blown-out engine.

3. Burning oil smell

A bitter, acrid smell goes hand in hand (unfortunately) with smoke. This could be another sign that your oil levels have been depleted, there is a major engine oil leak in the vehicle, or that the vehicle’s internal components are being compromised.

If your truck or equipment smells like it’s burning, it’s important to bring the vehicle to a professional mechanic so they can address the issue immediately and prevent lasting damage.

4. Engine light is on

While not always an immediate concern, keeping tabs on the engine light sensor is important, as the sensor often indicates if there is a problem with the vehicle’s oil level. If the light is solid yellow instead of light yellow, the vehicle needs immediate service.

After every drive, wait 30 minutes for the car or truck to cool down, and then inspect the engine to see if the engine is black, rusted, or caked with used oil. Doing so ensures that the engine light will only turn on for preventive maintenance-related issues or when a truck needs a routine motor oil change.

Sometimes, we’re not as proactive as we’d like to be, and we forget. After all, we’re human. When it’s not always possible to do a post-drive walk-around, all truck drivers, fleet managers, and drivers need to know the most common causes of a major oil leak. so that when trouble comes knocking, we’re ready to spring into action.

Common causes of a truck oil leak

Many truck drivers (and most laypeople) don’t have the luxury of taking a last look inside an engine bay to see how much oil is still left or whether there are any major leaks after a long drive.

That’s why it’s helpful to know the eight most common causes of an oil leak, to be prepared for the rough roads ahead — and ultimately save yourself a headache and trip to the local fleet repair shop. 

1. Broken or worn-out seals

These oil seals include camshaft seals, crank seals, and more. An oil seal can be broken as a result of driving on rough roads or coming into contact with road debris.

Whether it’s a few oil drops or a massive puddle, it’s important to inspect seals frequently to ensure the truck’s internal components function properly.

2. Worn-out oil filters

Oil filters need to be changed with every oil change. If not, they can be easily worn out. Sometimes, the root cause of an oil leak is simply not changing out a new filter.

And because these filters are handled often (most owner’s manuals recommend an oil and filter change every 3-6 months), it’s crucial filters are snug to prevent additional unwanted leaks.

3. Loose or over-tightened oil drain plugs and filters

Loose drain plugs can also increase the chance of an oil leak. It’s also important to make sure they are not overly tight. 

Otherwise, a vehicle may start leaking oil.

4. Infrequent oil changes

Most mechanics suggest coming in for an oil change every five to six months. For older vehicles, the standard was every 3,500 miles. But now, newer cars rack up 7,000- 10,000 miles before needing an oil change.

Let’s pause for a minute: 7,000 to 10,000 miles. That’s a ton of miles. Drivers must follow a consistent oil change schedule to prevent a major leak from occurring.

Along with proper tire rotation, checking a truck’s oil level often ensures that the oil inside stays healthy and lubricated instead of dry and crusty. Being proactive with oil changes will ensure no major damage occurs to the truck’s interior and exterior parts.

5. Extreme weather (and other driving conditions)

Snow, salt, sleet, rain, hail, and wind: the elements can take a toll on trucks and cars alike. These harsh weather conditions can exacerbate and deplete oil levels faster than in balmy, mild weather conditions. Plus, salt tends to corrode the components inside and near the engine and oil filter.

It’s crucial to ensure parts near the oil filter — like a car’s valve covers, front crank seal, camshaft seal, engine block, engine drive belts, engine cylinder head, and oil filler cap — are not corroded due to salted roads and arid conditions.

6. Cracked or dented gaskets

Gaskets are seals that often hold two pieces together. The gasket on a car or truck helps seal internal components that keep oil from spilling out of the oil pan.

Not fixing degraded engine gaskets can result in oil loss over the long run. It may look like a few drops here and there, but it is crucial to check the pan’s gasket to ensure no leaks occur. If leaking does occur and you’re not able to consult your local mechanic, check your owner’s manual for what can be done to fix your pan’s gasket.

7. Damaged oil pan

A damaged oil pan can result in a leaky system. It is important to make sure the seal on the oil pan is snug, to prevent oil from leaking into other key components like the engine.

To fix an oil leak, it’s important to ensure your oil pan is properly fitted.

8. Poor installation

A car and truck’s engine is hot. The average engine temperature hovers at 190-220 degrees Fahrenheit.

When engine oil leaks from a car or truck, it can pose a more serious threat to a vehicle’s life. Add on a loose drain plug here, the wrong rubber hose or camshaft seal there, and an engine oil leak can cause permanent damage to other internal parts of a car or truck.

It’s crucial to ensure items like your timing cover, valve cover, cylinder head, drain plug, oil pan gasket, oil filter, engine block, and camshaft seal are installed properly to prevent damage to other car and truck parts — parts like the fragile cooling system.

Doing so ensures problems are solved before they occur.

Common fixes for vehicles leaking oil

Truck drivers, fleet managers, and everyday citizens have busy lives. And time is valuable. Sometimes, it’s just not possible to make sure everything is snug before a problem occurs.

At Certified Fleet Services, we understand. In this section, we’ll cover some of the most common fixes for oil leaks from a truck or car.

Use the repair-or-replace mindset

This mindset can help determine whether your oil leak is serious enough to warrant a short repair or a complete replacement. For example, if you have a dented oil pan or scratched oil drain plug, there may be no need to replace it entirely.

A quick buff-out may be all that’s needed to have you back on the road.

However, if you notice smoke around any of the car’s internal systems, a complete repair might be in order. Burnt oil can cause damage to valves, seals, and other internal components. 

It’s important not to take these signs lightly and therefore take the time to fix them with a complete replacement — and pronto.

Engine or oil-stop leak additives

Let’s say you don’t have time to fix your valve seals and valve covers, let alone repair or replace them. An oil-stop additive might do the trick. Most additives soften and condition rubber seals to withstand rough conditions and prevent engine oil leaks from damaging other parts.

Note: using an engine additive is not a permanent solution but can be used to fix an oil leak if in a pinch. We recommend bringing your vehicle in as soon as possible.

Grab a torque wrench and bust out those tools

The common culprit to an oil leak are bolts that come loose from rough driving or extreme weather conditions. It can be helpful to check that your fleet, truck, or car’s bolts haven’t come undone. 

If possible, check the oil pan, the timing belt, valve covers, and then any other equipment you think might need some elbow grease and muscle. Of course, tightening the bolts doesn’t mean another leak won’t occur in the future, but doing so places drivers in the best possible situation to avoid these leaks entirely.

If a leak does occur though, Certified Fleet Services wants to make sure drivers are prepared to identify the type of leak so they can be proactive and fix them as soon as possible.

Common leaks that look like — but aren’t  — engine oil leaks

Finally, there are a few common leaks that look like engine oil leaks but aren’t. These common leaks include:

  • Brake fluid leaks
  • Coolant or antifreeze leaks
  • Power steering fluid leaks
  • Transmission fluid leaks

Brake fluid oil often looks like motor oil, because of its yellowish or dark brown hue. Coolant or antifreeze fluid looks blue or green. Finally, power-steering fluid is red, and fresh transmission fluid is dark red.

Choosing the right oil can make a world of difference for a truck’s engine and internal components. And when the right oil is combined with consistent preventive maintenance, a vehicle thrives.

TL; DR: 5-point summary

Too long; Didn’t read the article? Here were the five main points:

  1. If an oil — or car engine oil leak — goes undiagnosed, it can be an engine, fire, environmental, or personal hazard to people, plants, pets, and a vehicle’s health.
  2. Recognizing the signs and symptoms of an oil leak (oil puddles, burning smell, smoke, or engine light on) can help vehicle owners be proactive about maintaining their vehicle’s overall health.
  3. Preventing oil leaks — and recognizing their symptoms — includes learning the eight most common causes of an oil leak.
  4. Once a person knows the common causes of an oil leak, they can fix it with these three tips: the repair-or-replace mindset, oil additives, and a handy torque wrench to tighten loose vehicle equipment.
  5. If a vehicle is leaking fluid, but the fluid doesn’t look like motor oil, the fluid might be brake, coolant or antifreeze, transmission, or power steering fluid.

While an engine or vehicle oil leak may not seem like a serious issue, leaving these leaks undiagnosed and unfixed can decrease a vehicle’s value and output. And while it may be tempting to fix the oil change at home, the job is best left to a professional technician or mechanic.

At Certified Fleet Services, our mechanics and technicians have the perfect combination of skills and expertise for any job. For over a decade, we’ve serviced and maintained cars, trucks, fleet equipment, and much more. If you notice your vehicle leaking oil, reach out to us. See how we can help you in-shop — or from the comfort of your home or business — for all your truck, car, and fleet vehicle-related needs.