Obviously, car overheating and having smoke out of the hood indicate a critical situation. But how much are you aware of this kinda situation?
Why is your car overheating and smoking from under the hood? The significant causes of car overheating and smoking are damaged radiator, engine block, or cylinder head. It may also be due to a leaking coolant, a worn-out radiator hose, or an electrical issue.
This article reviews the common problems leading to your car overheating and smoking from under the hood and solutions to fix them. Also, it gives necessary information on what to do if your car is smoking.
Problems Causing Car Overheating And Smoking From Under The Hood
Let’s look at the leading causes of car overheating and smoking under the hood.
1. Low Coolant Levels
A running engine generates a lot of heat from the combustion of air-fuel and the movement of pistons. If this heat is not regulated, can cause overheating and smoking. Here the engine coolants help cool the engine to less dangerous temperatures.
But the cooling effect is reduced when the coolant levels drop below the standard, raising the engine’s temperatures. In most cases, the remaining coolant boils and leaks as vapor through the filler cap.
2. Poor Air Ventilation
Air-cooling vehicles depend on the free flow of air around the engine to cool the engine system. The fans in the radiator facilitate the same by blowing in cold air from outside through the air filters.
Poor ventilation around the engine causes an accumulation of hot air that causes overheating and smoking. Blocked air filters and hoses reduce the amount of cold air blown into the machine.
3. Faulty Radiator
Suppose your radiator is leaking or has a loose radiator cap; the coolant leaks and burns when it comes into contact with the hot engine block. Thus, the burning steams and comes out of the hood as smoke.
Accordingly, if the coolant is contaminated, it raises its boiling temperature and may lead to the boiling of the coolant in the radiator. The result is a burst through the loose cap as steam.
4. Damaged Cylinder Head Or Engine Block
The engine block is surrounded by coolant that may leak if the block cracks open. Mixing the fuel, engine oil, and the coolant result in overheating as the coolant loses its primary function.
Similarly, it happens to a damaged cylinder head when the fuel and oil mix and burn together. Once the engine overheats, it produces smoke from the burning parts and may lead to damage to other engine components.
5. Worn-out Radiator Hose – Leaking Coolant
A worn-out radiator hose leaks the coolant that burns when in contact with the hot engine block. The coolant boils and escapes as steam from under the hood.
This leaking coolant may also boil due to the raised temperatures, thus evaporating through the radiator cap.
6. Overused Or Low Levels Of Engine Oil
The engine oil is used to lubricate the engine’s moving parts and regulate the engine’s temperature. As the oil flows through the engine parts, it absorbs excess heat and releases it to the environment.
Low engine oil levels reduce the amount of heat transferred, causing overheating of the engine. If the oil has been used for a long, it loses its functionality value and no longer helps to cool the engine.
An overheated engine causes a burning effect on the engine rubber and plastic parts that produce smoke from under the hood.
What Are The Different Smoke Colors From Under The Hood – What Do They Mean?
The color of the smoke from under your hood can help determine the problem at hand even before inspecting it. Let’s look at the various colors and their meaning.
- Black smoke – Black smoke is often associated with impurities in the fuel. It may be due to coolant leakage into the combustion chambers, causing a black smoke leakage.
- Gray or white smoke – A white or grayish smoke indicates water leakage into the engine. It also shows electrical smoke.
- Bluish smoke – The blue color indicates oil burning in the combustion chambers.
If you notice steamy smoke from under the hood, check for boiling coolant in the radiator.
How To Fix Car Overheating And Smoking From Under The Hood?
To fix the problems listed above, you must first identify your vehicle’s problematic parts.
Step 1: Stop the engine and allow it to cool down
Step 2: Open the hood
Step 3: Allow the smoke to clear for better vision
Step 4: Check for any damaged parts or leaking points in the cooling system
Step 5: Mark these points and get the right tools to fix them appropriately
If you are alone and the problem is complicated, such as a cracked or damaged cylinder head and engine block, tow the car for mechanical assistance.
For minor problems that can be fixed, act on them with sealants to stop further leakage. A wiring connection problem should be addressed using tapes and changing the affected fuse.
If you have access to the repair store or garage, replace the damaged parts to avoid such problems in the future.
Why Is My Car Smoking From Under The Hood But Not Overheating?
Most cases reported indicating that a smoking vehicle from under the hood records a temperature rise. However, this is only sometimes the case. You might have no instances of car overheating but still get smoke steaming from under the hood.
Below are some of the reasons for your car smoking.
1. Electrical Smoke
The electrical system may result in a cloud of white smoke from under the hood due to short-circuiting. When naked wires get into contact with each other, they short circuit, producing sparks and, at times, burning the insulation, producing smoke.
Thus, the electric smoke has a pungent smell of burning plastics and ceases after the fuse blows out.
2. Rubber And Plastic Smoke
When exposed to high temperatures, the engine and its components have some plastic parts that may burn out or melt. The pulley cables tend to burn from friction-producing smoke if not well lubricated.
Ensure all moving parts are well lubricated and ventilated to avoid burning from friction.
How To Avoid Overheating And Smoking Problems In The Future?
To avoid overheating and smoking issues with your car, consider practicing the following;
- Inspect the water and coolant levels in the reservoir before embarking on a long-distance journey
- Perform regular servicing of the vehicle to detect leakages and faulty parts in advance
- Have the air filters and fans cleaned after driving on a dusty road
- Avoid topping up coolants and engine oil on the old one, as it reduces the quality of the new refill
- Always inspect the engine oil after driving for long distances
FAQs
Check these frequently asked questions to understand better why your car is overheating and smoking.
Yes. You can drive for short distances at a slow speed after the engine cools down to seek mechanical assistance.
However, if your vehicle emits colored and smelly smoke indicating a more severe problem, stop the car and fix the problem.
Stop the engine and allow it to cool for at least 15 minutes. Open the hood and inspect for the possible cause of smoking and overheating.
Fix the underlying issue if it is a minor problem or call for mechanical assistance if the damage is enormous.
If your car indicates no signs of overheating but still smokes from under the hood, check on a possible electrical problem, such as short circuits. You can also check on the plastic components that might be burning out.
Conclusion
An overheating vehicle often produces smoke from under the hood, indicating that the cooling system has problems. The main cause is leaking coolant to the hot engine block, damaged radiator, and cracked cylinder head and engine block.
Worn-out head gaskets allow the engine oil and fuel to mix, burning to produce a blue smoke from under the hood. Always identify the cause and fix the problem before progressing on your journey.