What Smoke In The Exhaust Means
Cars are built better and more durable today than ever before. But, things continue to go wrong and can lead to expensive repairs (not to mention frustration). Sometimes, while driving, your car will start spewing spoke from the exhaust. That can imply a number of potential issues under the hood. In this article, I’ll explain the types of smoke you might see, how to figure out what the problem is, and ultimately, what you should do about it.
Different Colors
If you notice smoke coming from your vehicle’s exhaust, it will most likely be 1 of 3 colors: white, black, or blue. If it’s blue, you have a problem. It usually means that oil is burning in your engine for some reason. In my experience, it’s often caused by bad piston rings. But, the blue smoke can also result from a broken cylinder or a problem in the valve guide.
White smoke isn’t much better. It often happens as a result of burning transmission fluid when the fluid leaks into the engine through a hose. Burning coolant can also cause the problem if your cylinder head is cracked or broken, or your head gasket has developed a leak. Finally, black smoke has a couple of potential causes, depending on the kind of car you’re driving. If it’s an older model that uses a carburetor, the choke plate can stick. Otherwise, the fuel injection system may have sprung a leak or the air filter may be filthy and congested.
Diagnosing The Problem
Besides the color of the smoke, there are other signs that a problem may be lurking in the bowels of your vehicle. For example, if the smoke is blue, it will usually smell like burning toast. Check your oil to make sure it’s full and look at the pistons to see whether they’re worn or broken.
Burning transmission fluid smells the same way. Similar to the oil, check the levels and replenish the fluid as needed. While the hood is up, look at the vacuum hose that goes from your transmission to your engine. If there’s fluid inside, you may need to buy a new modulator valve. If coolant is burning, you’ll notice a mildly sweet odor. You can identify whether the issue is with the head gasket or cylinder by pressure testing the cooling system.
Black smoke is usually the easiest to diagnose. If your vehicle is using a carburetor, check the choke plate to see whether it’s sticking. Otherwise, test the pressure of your fuel injection system and take a quick look at your air filter. If it’s clogged, replace it.
Fixing The Problem
If you’re handy with car parts, doing the repair work associated with black smoke won’t pose a challenge. On the other hand, if you’re noticing white or blue smoke, take your vehicle to a repair shop that you trust. The mechanics may need to overhaul the car engine or remove the cylinder head. It’s better to have trained hands performing those jobs.
