7 Causes of white smoke from exhaust on startup, when accelerating & Idle

Sharing is caring!

Last updated on August 1st, 2023 at 07:39 am

When you notice any kind of smoke from your exhaust be it white smoke from exhaust on startup or when accelerating and even when idle, they all are indications that, your vehicle is having one issue or the other that needs your attention.  

How serious this will be, is totally dependent on the color and type of smoke that is coming out.  In most cases, smoke coming out of the exhaust are usually due to condensation accumulated within the exhaust. The smoke produced for this reason will not have a direct impact, however, it’s important that you understand the meaning and why you may see white smoke from exhaust on startup. Smoking is not limited to startups, you may also see white smoke from the exhaust when accelerating and on rear cases, you may as well see white smoke from the exhaust when idle. Related is this post on a straight pipe exhaust system.

There is a special scenario where white smoke on startup then disappears, we will talk about this here in this post.

But you must recognize that the information we share here, is of general note and so in special cases, you need expert mechanic advice that is specific to your circumstance and condition in other to fix or rectify the problem.  

So let get into this article fully.

7 Causes of white smoke from exhaust on startup |white smoke from exhaust when accelerating and when idle

So if your turn on your car especially gas engine cars, then you see white smoke from the exhaust on startup, there are a couple of reasons this is coming out, but you need to know on normal circumstances white smoke is t harmless.

However, there are times when it becomes a cause for concern and so we need to quickly sort for fix the problem of yielding the smoke in various conditions.

So let’s start with why you might see white smoke from exhaust on startup.

Related Article: Does straight pipe waste more gas

What Causes White Smoke from Exhaust on Startup

White smoke coming out of the exhaust pipe might result due to so countless reasons however when you see white smoke from the exhaust at startup, just know that your car is probably are having one of the following issues below:

• A bad, warped or cracked cylinder head.
• Failed or Faulty Head gasket
• A cracked, Fractured or Bad engine block

So the reason any of the above issues may lead to smoke coming out of your exhaust pipe is that when there is a fracture on the engine block, head gasket or cylinder head, it allows coolant to start leaking into the car engine combustion system and the cylinders which then alters then normal operating system of the car and this is very unsafe for the engine and could damage the engine on a long run.

That is why we recommend you seek a solution the moment you notice white smoke whether it is the normal one that is harmless or not. Just look for a mechanic to run a check on the car, or better still do it yourself.

So let’s now look at why you see white smoke from the exhaust when accelerating

What is the causes of white smoke from exhaust when accelerating?

The main cause of smoke from the exhaust when accelerating is a burning coolant or transmission fluid problem.

• White smoke due to transmission fluid

When the white smoke is a result of transmission fluid, it means that the car engine is likely absorbing excess fluid from the vacuum pipe or hose which is what makes it produce white smoke.  

This issue will also make the exhaust produce a smell like a burned oil so you should look out for this as well.

• White smoke due to Burning Coolant.

If the white smoke is caused due to coolant, then it is very much likely that your car has a cracked cylinder head.

Or a leakage from the head gasket. This will normally come with a sweet pleasant smell.

• How to diagnose this problem?

To check this, you want to run a pressure test on the vehicle coolant. Observe if they are low and if the car engine is excessively heated up. If it is overheating then it is a coolant problem with low coolant, but if it is not overheating then your car head gasket is leaking.

In this situation, you need to change it to a new one.

Watch this video on how to change your head gasket.

quick fix for white exhaust smoke

If transmission fluid is the problem, you need to fix this by changing out the transmission vacuum modulator valve.

But before changing it, you have to observe the fluid level to see if it is low or at its normal level. If it is below the normal level, you only need to add more transition fluid to meet the required amount.

Next in line is why you may see white smoke from the exhaust when idle.

What causes white smoke from exhaust when idle?

So in a case where you notice white smoke from the exhaust when idle or stopping your car, it simply means that there is oil within your car combustion chambers. The presence of oil in the combustion engine burns off your car exhaust system which makes your smoke as one of the many symptoms it might present other than smoking.

The easiest way to identify this as the problem is to notice the white smoking coming out when idle and then you also want to observe that what is burning is oil and not gasoline.

To recognize the various burning condition for both gasoline and oil or transmission is simple.

Gasoline burns explosively while transition fluid is subtle.  Read this article to better understand how transmission fluids burns.

For burning issues with your transmission oil, you need to seek a solution as quickly as possible because the longer you allow the oil to stay inside the more problem it is causing to your car spark plug which might keep you stranded in a location you are helpless to do anything to replace them.

What Causes White Smoke from Exhaust Once Cold?

In the weather condition, the white smoke may be quite traditional, however in some things, it is not. Continuous white smoke whereas driving is one amongst them. If you’re having a diesel, white smoke is also unburned fuel or fluid browsing the engine. But mostly, it’s the wrong widget temporal arrangement within the cylinders.

What Causes White Smoke from Exhaust Smells Like Gas?

Drivers should perceive the concept of smoke from cars. Usually, it’s vapor or steam, since it’s introduced into the chamber. For that reason, you’ll have the water dripping from the pipe. Drivers also can see the water within the fuel or a leak within the gasket.

You might suppose it’s traditional, however, that’s the engine misfiring and pushing raw fuel out. In those cases, the automobile is running rough and drivers will smell a raw fuel smell.

In order to repair this, simply check the fuel and replace if necessary and follow the steps below.

So, in this part of this post, we will look at how to remove white smoke from the exhaust when starting the car, while accelerating and idle by identifying which part of the car the antifreeze coolant leaks into and stopping the leakage. That is the solution to this white smoke problem.

Let us begin right away.

How to Remove white smoke from the exhaust when starting the car

What does white smoke from the exhaust pipe mean?

It is possible that condensation could be the reason for the white smoke. If the smoke is thin, you have nothing to worry about. The smoke will soon fade out. But if it is thick smoke, it may be the signal of something more serious like a damaged cylinder head, blown gasket, or a cracked engine block.

These three items will cost you some real money to repair the car. Another factor you should consider is the burning of coolant.  When there is a tiny leak of coolant this could cause the engine to overheat. So if coolant leaks, it could mix up with oil and spoil vital engine parts.

Therefore let us see the steps for identifying the problems to provide a solution to it

Steps to stop white smoke from your car the exhaust when starting car

So, to stop the white smoke from your car follows these steps.

• Examine the Intake Gasket

The work of the intake gasket is to distribute the coolant in the right proportion to each part of the intake port of the car’s cylinder head. Note that there is a gasket that is supposed to seal that manifold to the cylinder head. But if that has a problem and does not do its work well, coolant will flow into the combusting chamber.

Hence, to confirm this possibility, you will have to remove the intake manifold and check the gasket thoroughly to check whether there is a leakage or rust.

After inspecting the gasket if it does not have any coolant mixed with oil inside it, then go to the next step.

• Inspect the Head Gasket Again

In a bid to remove the white smoke from the exhaust when starting the car, after you have confirmed that the intake Gasket does not contain coolant, continue your search for the cause of the white smoke.

Also, inspect the Head Gasket that seals the Cylinder Head by looking at the block through which the coolant enters the Cylinder head. Furthermore, if there is a leakage in that part, it will allow the coolant to enter the combusting chamber. And this will cause a stream of white steam to come out of the exhaust pipe.

• Search for a crack In the Cylinder Head

Examine the Cylinder Head. This part is made of Aluminum and could break easily due to overheating. Go ahead and change it if it is broken or cracked. The Cylinder head must function well to consistently seal just like the Engine block and head Gasket does.

As you can see, we have isolated the cause of the problem in three places. All it takes, to solve this white smoke problem is to cut off the supply of coolant to those parts.

However, you know that a job that is easy for a professional mechanic will be difficult for an amateur. So, I advise that you give the car to an experienced auto mechanic to handle. (How To Straight Pipe A Car)

What Coolant Does in Your car and other Symptoms to look for

As you would already know by now, Coolant is an antifreeze liquid for cooling the Engine temperature. And, white smoke, comes out from your exhaust pipe whenever the coolant enters the combusting chamber of your car Engine.

In addition, a strong odor also comes out with the steam and helps you to diagnose this problem fast.

Finally, when you are searching for how to remove the white smoke from the exhaust when starting a car, you should consider other symptoms like overheating the engine and the reduction of coolant from the container when there is no leakage that you can point to.

White smoke from exhaust when accelerating

Too Much Oil in the Car Engine.

Now this is one mistake a lot of people make, especially when they change their oil and they end up having smoke coming out to tailpipes and they are freaking out and thinking it is a bad engine.

Meanwhile, they simply put too much oil in their engine and overfilled the crankcase.

Also putting too little oil in your engine could definitely damage your engine but also, putting too much oil in your engine could cause it to smoke and then will also cause severe mechanical damage as well to the engine.

You see, what happens when you overfill your engine with oil, is that the engine oil starts getting past your piston rings to the top of the cylinder, and then from there it gets into your combustion chamber and then burns off with the air-fuel mixture.

And from there it comes out through the car tailpipe

How to fix this?

Fixing this is pretty easy.

Obviously, make sure you’re parked on a level surface and then check your oil level and make sure you don’t have too much oil in your engine.

Bad positive crankcase ventilation valve

The next reason you could have smoke coming out of your tailpipe is, that if you have a bad positive crankcase ventilation valve.

Basically your PCV valve or your PCV system is responsible for recirculating or regulating the blow-by from your crankcase, back intake manifold, and your engine.

So when your car piston comes up and reaches the top of the center of the crankcase, the spark plug ignites the fuel mixture inside the combustion chamber and as a fuel mixture ignites, it then expands.

As this happens, it pushes the cylinder down and the cylinder board creates power but also some of those gases slip by, the piston rings and into the crankcase.

And from those gasses find their way to the cylinder head where the PCV Valve under certain driving conditions allows them to be recycled through the intake manifold and then back into the combustion chamber and be reused.

Now if you have a bad PCV valve that is stuck in a position where it’s allowing for a maximum flow of the blow-by gases from the crankcase to the engine even when it’s not supposed to.

Then your engine could actually be sucking in a bit of your engine oil and burning it through the tailpipe

Also, watch this video to see the more likely reason why you could have white smoke from the exhaust when accelerating.

So this is where we will end it for this post on the Causes of white smoke from exhaust on startup and when idle, accelerating, and cold I hope this has helped you.

You might have to watch this video to see how to fix some of this white smoke problem.

Related Article: How to Remove white smoke from the exhaust when starting car

Sharing is caring!