There are some things drivers expect to change color — like traffic lights, for example. Your exhaust fumes, on the other hand, shouldn’t have any color at all. In winter, you may be able to see puffs of white smoke coming from your exhaust pipe, which is totally normal. But during daytime and warmer weather, it should run completely clear.
If at any point you notice that your exhaust fumes have a tint to them, take it as a warning sign that something isn’t quite right under the hood. In some cases, the colors of smoke can even be dangerous. Below you can find out about the different colors your automotive exhaust fumes can turn, common causes, and what they might mean for your vehicle.
If you own a diesel engine car, make sure to consult a technician instead — the following information is geared towards gasoline engines and may not apply in your situation.
What Blue Exhaust Smoke Means
Most likely diagnosis: Major oil leak
Potential cause: Worn piston rings or valve seals
So, you’ve turned the key in your vehicle and notice that the exhaust is running blue smoke, or perhaps a shade of gray. But what could this mean for your engine? Unfortunately, the prognosis isn’t great.
First of all, switch everything off again and do not drive the vehicle under any circumstances. Blue smoke or gray smoke is an indication that a significant amount of oil is being leaked into the combustion chamber and is being burned there. This is a major issue, as oil is needed to protect the engine from seizing up, and can also catch on fire from oil burning or oil fire.
If this happens to you, do everything you can to protect your engine and yourself. Call a tow truck and have them take you to your closest certified auto shop.
What White Exhaust Smoke Means
Most likely diagnosis: Coolant leak
Potential cause: Blown head gasket or cylinder head
White puffs of smoke from your tailpipe during the winter months are to be expected, but spot white exhaust smoke at any other time and you could have a problem on your hands. Depending on the severity of the issue, you might also see white smoke coming out from under the hood.
This is caused by coolant bleeding from your engine and evaporating, which obviously isn’t ideal. Coolant fluid is required to prevent a car’s engine from overheating, and when there isn’t enough remaining, things can go wrong quickly.
If you’re on the road when this happens, pull over to a safe spot as soon as possible. Driving while your engine is overheating can cause permanent (not to mention expensive) damage, potentially even resulting in a cracked engine block or other engine damage.
What Black Exhaust Smoke Means
Most likely diagnosis: Incomplete combustion of fuel/air mixture
Potential cause: Clogged air filter or fuel injector problems
If clear exhaust fumes are the norm, then thick, black smoke is most certainly a sign of a problem. But what kind of problem, and how serious might it be?
Usually, black smoke is an indicator that the fuel-to-air ratio is too rich, meaning that there is too much fuel for the amount of air entering the cylinders. This can be caused by the quality of the gasoline you’re using, engine airflow problems, or issues with your spark plugs and/or ignition coils. In the most extreme cases, however, it can also be caused by a fuel leak, which is arguably the most urgent of all issues your exhaust system fumes could potentially warn you about.
Gasoline is, of course, highly combustible, so an engine fire is a real risk if you continue to drive while a fuel leak persists. You may even see sparks and flames coming from under your vehicle’s hood. As with all issues related to exhaust smoke, the safest course of action is to switch off the engine and contact roadside recovery. It’s always better to be safe than sorry, so have a professional take a look before things have the opportunity to get worse.
What to Do When You Notice Unusual Exhaust Smoke
If your exhaust fumes aren’t looking too healthy, it’s highly recommended you take action immediately. Things you can do include:
- Turn off your vehicle as soon as you possibly can: In the best-case scenario, your car is stationary when you notice there’s a problem, but if you’re on the move, make it your priority to safely pull over and turn off your engine. Doing so will prevent further damage to your vehicle and keep any auto repair costs as low as they possibly can be.
- Check fluid levels: When exhaust smoke is an unusual color, leaking fluid is usually the culprit. By taking a moment to check levels of coolant, oil, and all other fluids, you can potentially diagnose the problem yourself. If any of them are low, they’re most likely leaking somewhere.
- Use a diagnostic tool: Your car’s onboard diagnostic (OBD) computer can tell you a lot about what might be going on under the hood. If you have a diagnostic scanner, you can connect it to the vehicle and decipher the codes it reads back to you. OBD codes can seem complex at first, but there are plenty of free online resources available to help you understand them.
- Consult a professional: There are some exhaust-related issues that you may be able to diagnose (and even fix) yourself, but in the vast majority of cases, a professional eye is required. By having your vehicle towed to a trusted mechanic, you’ll avoid exacerbating the problem, and certain things will be fixed to a professional standard.
What Is an Extended Auto Warranty?
When a brand new vehicle is sold at the dealership, it comes with what’s known as a factory warranty or manufacturer’s warranty. This is a promise from the automaker that what you’ve purchased is fit for purpose, and that they’ll repair or replace any components that fail due to fault within a predetermined number of years or miles traveled (whichever comes first).
While your factory warranty is in place, you can drive with almost total peace of mind, knowing that the vast majority of unexpected issues will be rectified free of charge. All good things must come to an end, though, and the second this coverage expires, you will be financially responsible for the cost of future car repairs. From unusual exhaust fume colors to infotainment malfunctions, if you want them fixed, you’ll have to pay for them.
Thankfully, there are ways to protect your wallet, with most people taking one of two routes. The first of these is a more traditional extended warranty, which can usually be purchased via a dealership or sometimes directly from your manufacturer. This does what the name implies and extends your factory warranty coverage, but not without some significant drawbacks.
For example, all repairs must be carried out at an authorized dealership (which could be hundreds of miles away). Worst of all, you can only be eligible for an extension while your factory warranty is still active — ruling out used vehicle owners altogether.
For a number of reasons, most drivers prefer to opt for a vehicle service contract from a third-party provider. Not only do you pay less for almost the same level of coverage, but you can have work carried out at any certified auto shop, and covering used vehicles is rarely a problem. Some providers will even cover high-mileage vehicles, and most throw in some helpful added benefits to sweeten an already great deal.
Once coverage is in place, breaking down is a lot less of a worry. As long as the affected component is included in your contract, all you need to do is visit the appropriate repair facility, and your provider will take care of the rest. With the average annual cost of car ownership only ever on the rise, having your repair bills taken care of can save you hundreds (if not thousands) of dollars per year—not to mention stress!
How Endurance Can Help Cover Mechanical Issues
Drivers looking for a reliable third-party extended auto warranty need look no further than Endurance. Since our founding in 2006, we’ve helped thousands of drivers save serious money on unexpected repair bills. Today, we’re known as the country’s Best Vehicle Protection Plan Provider, and we’re here to help you too!
Our wide range of plans has something for almost everyone, ranging from basic powertrain protection right up to fully comprehensive coverage. Whether you’re a casual commuter, road trip enthusiast, or even a luxury car driver, we’ve got you covered. And if none of the base plans quite suit your needs or budget, an Endurance advisor will be more than happy to tailor a bespoke program that does.
As well as market-leading coverage, we also offer some amazing added benefits as standard with every plan. Sign up with Endurance today and enjoy 24/7 roadside assistance (including towing, fuel delivery, and lockout services), rental car reimbursement, and trip interruption coverage.
As an Endurance customer, you can activate a year’s worth of our Elite Benefits package.* This adds on up to four tire repairs or replacements annually, key fob replacement, up to $500 in collision discounts, and up to $1,000 in total loss protection.
Keep Your Vehicle Covered and Drive with Confidence
Unusual exhaust smoke colors are never a good sign — though some are certainly worse than others. Whatever the underlying issue, the best course of action is to switch off the engine and seek the assistance of a professional mechanic before further damage can occur. In any case, with a vehicle service contract from Endurance watching out for you, you can rest assured that you’ll be looked after.
To find out more about Endurance coverage and how it can help you save on the ever-rising cost of car ownership, give our plan advisors a call at (800) 253-8203 to request a FREE quote. Or, if you’d prefer to have a read through plan suggestions and pricing first, you can shop our eStore instead.
We also have an extended warranty blog where you can read other helpful articles just like this one, including topics like seasonal maintenance, warranty provider comparisons, and more.