Our cars are important to us; they grant us access to freedom in so many ways. Whether it’s driving to school, work, the grocery store, a doctor’s appointment, or just enjoying the world around us, we depend on our car to get us there. Efficiency, safety, reliability, and longevity are the basic traits we seek in a car – for the most part – with the latter two being the focus for many modern car buyers.
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One of the most important steps to maintaining an engine’s efficiency and reliability, and to prolong its lifespan, is to perform routine maintenance and keep up with services. A basic oil change is one of the most important maintenance items to keep abreast of. Whether you leave it to the pros or tackle the job yourself, most of us know, sooner or later, our car will be due for another oil change. And when the job is done, it’s all the more unsettling when things go wrong, leading us to asking, “Why is my car smoking after an oil change?”
Don’t panic! We have the answers in this article where we’ll break down exactly what can cause engine smoking after an oil change.
The Importance of An Oil Change
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The purpose of engine oil is twofold, and if you’re new to driving and car ownership, this is quite important: firstly, it acts as a lubricant to prevent the metal bits of your engine grinding against each other and wearing out due to friction, and secondly, engine oil helps keep your engine temperature low by dispersing heat from the combustion process. Without engine oil, your car would overheat, even if it were able to function without the lubrication, so it’s essential to have the right type and amount of engine oil for your car.
With tighter engine tolerances and Variable Valve Timing (VVT) systems that rely on sufficient oil pressure and flow to operate, the refinement of engine oil and the technology behind it has substantially improved. Synthetic oils ushered in the era of long service intervals. Still, engine oil maintenance is likely to be more important in today’s vehicles than in vehicles of the past.
Related How often should you get an oil change for your car?
Every manufacturer has their own guidelines and you should always check your car’s manual, but as a general rule of thumb, it’s a good idea to get an oil change every 10,000 miles or every year, whichever comes first.
Identifying The Problem: What Color Is The Smoke?
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Whether the smoke appears to be coming from the engine, or the smoke is coming from the tail-pipe, the color of the smoke matters when trying to find the source.
On cold starts, it’s not uncommon to see lightly colored exhaust gasses from the tailpipe. Temporarily white-colored exhaust fumes are due to moisture inside the engine and exhaust system. Once the system reaches operating temperature, the colored plumes will dissipate.
It’s important to try locate where the smoke is coming from. Smoke coming from the vehicle’s exhaust will indicate an engine issue. See our chart below to identify the possible causes of exhaust smoke coming from your car by using its color.
Exhaust Smoke Color
Color
Possible Causes
Blue – Burning oil
Worn piston & rings Leaking valve seal(s) Worn turbocharger Faulty PCV Overfilled engine oil
White – Burning water/coolant or ATF
Worn/leaking head gasket Leaking vacuum modulator Condensation
Black – Excessive fuel (rich)
Excessive fuel pressure Leaking injector(s) Faulty ECT sensor Fault a/f sensor Defective MAF sensor Faulty Ignition system
Reasons Why Your Car Is Smoking After An Oil Change
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As we mentioned above, whether you just picked your car up and paid the service bill, or started the car up after doing the oil change yourself, to find smoke coming from the engine can be disheartening. There can be a few causes of this and they can usually be easily avoided.
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Oil Spills
The most common cause of smoke coming from the engine or around the exhaust system is engine oil that has spilled on the engine or exhaust manifold, and it’s now burning. There is usually a noticeable burning oil smell accompanying this. Oil spills can happen with simple carelessness, by accident, or from not using the right tools to reduce the risk of spills. You can buy threaded oil funnels that fit specific applications to reduce spilling; these are recommended if you do oil changes often, or if you are working as an auto service professional. This is a great investment that improves cleanliness and prevents issues after the fact – it’s one of the things every gearhead should have on hand.
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Oil & Fluid Leaks
The second most common cause of white smoke coming out of the exhaust after an oil change is oil and fluid leaks. If any fluid makes contact with a hot engine surface such as the cylinder head, exhaust manifold, or intake manifold, smoke will appear. If your engine is leaking fluid, it’s likely the cause of the smoke. We recommend replacing any leaking seals starting from the top of the engine and working your way down. It may be helpful to clean and degrease the engine and use UV dye to locate the source of an oil leak.
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Insufficient Service
If the smoking only appeared after the oil change or mileage interval service was performed, odds are the oil change process wasn’t completed correctly. Most people know to replace the engine oil filter, lubricate the o-ring, and make sure the drain plug is tight. However, there are other steps to performing an oil change to ensure the car doesn’t come back or to prevent smoking.
Replace the drain plug gasket: Many people overlook this step, and it results in oil leaking from the drain plug. Some drain plug gaskets can be reused but most manufacturers state these are one-time use. Inspect the filter housing for cracks or surface marring. Ensure the oil filter is not ‘double-gasketed’ as this is another common cause of oil leaks. Clean the oil pan and oil filter after service. Many experts recommend spraying the oil pan and oil filter with brake parts cleaner, then wiping away any residual oil with a shop towel. This not only prevents oil drips and smoke but allows you to efficiently inspect the areas after performing the service for leaks.
Incorrect Oil Type & Amount
Unfortunately, using the wrong oil or not using the right amount can also cause smoking. If you find smoke (specifically blue) being emitted from the exhaust after a service was done, odds are the incorrect oil was used or too much oil was added to the engine. Using the incorrect engine oil can cause damage to the moving parts; if it’s too thick, it will reduce your fuel efficiency as it creates more resistance between the moving parts. If it’s too thin, it could lead to incorrect oil pressure, and it won’t be able to disperse heat as effectively. Both are serious issues.
On the issue of overfilling the engine with oil, this is a common cause of engine smoking as it increases the chances of a leak. Too little oil is a more obvious issue, as it means your engine is running without lubrication or effective cooling. Always stick to the recommended volume of engine oil, which you can find in your vehicle’s owners manual.
If you’re buying a used car, this is one of the
most important things to check before buying
: always test drive the car first and keep an eye out for any smoke from the exhaust when you do. It can be a symptom of a badly-maintained car or a sign that something is wrong.
FAQs
Can too much oil make your car smoke?
Yes, it’s common to find oil pooling in the intake if too much oil is added. This oil pooling causes oil to be burned in the combustion chamber. Additionally, adding too much oil creates oil leaks, both of which cause smoking.
Can not changing oil cause a car to smoke?
Yes, if routine oil changes are not performed, sludge builds inside the engine. A sludge-ridden engine is likely to smoke, suffer premature wear, have reduced power, and have reduced efficiency.
What other causes could there be for white smoke after an oil change?
Sometimes the white smoke after an oil change is because of other issues like water or coolant getting into the combustion chamber if its leaking into the head. It could also be because of water in the exhaust after being washed.
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Mobil
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MachineryLubrication
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