Causes of Blue Smoke From the Exhaust of a Truck

The exhaust gases can tell you a lot about the condition of your truck. But what are the causes of blue smoke from the exhaust of the truck? When everything is working in perfect condition, your truck will emit a thin white smoke or very light smoke accompanied by water vapor. If you see blue smoke from your truck exhaust, something is wrong, and you should fix it immediately.

What are some of the Causes of Blue Smoke from the Exhaust?

Various reasons can lead to the emission of blue smoke from your truck. This guide will help you understand the common cause such as oil problems, turbochargers, or PCV valves.

Presence of Oil in the Combustion Chamber

The combustion chamber is composed of pistons, cylinders, and valves. The primary role of oil in the engine is to lubricate the moving parts. Pistons move in the cylinders, so they must be lubricated. The pistons have piston rings that ensure that oil does leak into the combustion chamber.

If the piston rings wear out, the oil will leak into the combustion chamber. It will mix with fuel and air. When this mixture burns, it produces blue smoke. A cracked valve seal also leads to oil mixing with fuel and air in the combustion chamber.

Faulty Turbocharger

If your truck has a turbocharger that has blown out, you will see blue smoke from the exhaust. It can also result from a leaking oil seal. Oil will seep into the engine, and if this happens, it will mix with fuel, producing blue smoke from the exhaust system.

Faulty Piston Rings

The pistons’ rings keep oil in the combustion chamber at its right position. Oil is not supposed to move into the combustion chamber. Oil will find itself in the combustion chamber when the piston rings are damaged or faulty.

As air, fuel, and oil mix, you will see blue smoke from the exhaust of your truck. Unfortunately, it is pretty costly to replace the piston rings.

Dripping Oil

When something is wrong with your truck, and hot oil starts to drip from the engine, there is a high chance this oil will come into contact with the hot areas of the engine. When this happens, you will see blue smoke as you accelerate. The blue smoke will result from oil hitting up the engine block. Such does not come from the exhaust, but it will look like it is.

Suppose oil drops from a blown gasket in the engine block. It will make its way into the hot exhaust, which will produce blue smoke.

Faulty PCV Valve

The positive crankcase ventilation does the role of releasing pressure that accumulates in the oil pan. The released pressure goes to the intake manifold for the fumes to be re-burned. When the PCV is stuck, the oil will mix with air and other gases. The intake manifold is connected to the air filter, which produces blue smoke.


The production of blue smoke is common, especially when part of your truck’s engine starts to wear out. When you see blue smoke from the exhaust of your truck, these are some of the common causes that you should pay attention to when doing maintenance

Water Coming Out of Exhaust – Why Water Is Coming Out of My Truck Exhaust?

If you have experienced water coming out of exhaust, then it should ease your mind to know that you can easily know the problem. Trucks have an internal combustion engine whose by-product is exhaust gases. After complete combustion, the outlet valve of the combustion chamber will open to let the exhaust fumes into the exhaust system. The exhaust system has various components, from the engine to the tailpipe. At some point, you will observe water coming out of your tailpipe, which might signal leakages from the exhaust system. 

Water Coming Out of Exhaust

Water coming out of exhaust should not make you worry because it does not symbolize any serious issue with your truck. But it is necessary to find out the actual cause of water from the exhaust system and fix it as soon as possible. Doing this will enable you to troubleshoot your truck and fix it. Here are some of the reasons why water might come out of your exhaust system.

Hot Engine

The engine will be heated most when you start your truck for the first time in the day. The oil will flow to various parts to cool down and lubricate your engine. Before this happens, your engine and the exhaust system will be very hot. If it is cold, you will see water droplets from the tailpipe of your truck for a while before drying up.

Condensation of Water in the Engine

During combustion, your truck will produce some pollutants, such as carbon dioxide, nitrogen, and water vapor. When the exhaust fumes are exiting the combustion chamber, water and carbon dioxide mix as your engine is cooling down, and as this happens, you will be able to see condensed water from your exhaust pipe.

The Catalytic Converter Performing its Role

Water coming out of exhaust might not be a bad thing after all. The catalytic converter is an essential part of the exhaust system. During combustion, harmful gases are produced, and the catalytic converter has metallic components which neutralize the harmful gases by initiating chemical reactions. During such reactions, the harmful gases are reduced to an environmentally friendly substance such as water. On most occasions, the reactions in the catalytic converter make your truck produce water from the exhaust pipe.

Faulty Head Gasket 

A faulty head gasket is a serious problem for your truck which you should address as soon as possible. When your head gasket is blown, your truck will white smoke accompanied by water droplets. You will also be able to witness air bubbles in your coolant reservoir and also overheating problems.

Damaged Pistons and Rings

Damaged pistons and rings can make your truck produce water from the exhaust system. To determine this, you will see smoke accompanied by water coming out of your exhaust system. Sometimes, when this issue is worse, the smoke will be accompanied by a sweet smell. In this case, you need to stop immediately and seek mechanical assistance.


Having looked at some of the causes of water coming out of exhaust, we hope it helps you easily deal with it. The effects of water vapor are the most common cause of water droplets from the tailpipe. You will experience this when you start your truck on a cold morning. Sometimes, the presence of water might signal serious issues which you will have to fix for your truck to keep serving you.