I smell gas and it blows white smoke out of the exaust.

She fires right up, No problem there. The issue is I smell gas strong. Gas millage is horrible. There is white smoke from the exaust. Every once in a while she seems to hesitate to shift into second after take off.

My car has 88000 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
Hi There,
There are a number of things that can cause poor fuel mileage. A faulty camshaft position sensor is one of them. The camshaft position sensor is a magnetic sensor that monitors camshaft speed to regulate ignition timing and fuel injection timing. It gathers and sends information about the car’s camshaft speed (and as a result the position of each piston) to the car’s electronic control module. This information is received by the computer, which then uses this data to further calculate the time of ignition and the timing of fuel injection required by the engine. When this is not working properly, you may experience a drop in power, poor idling, poor fuel mileage and problems starting the vehicle.

A clogged or dirty EGR valve may also cause poor fuel mileage. The EGR valve is a small component designed to allow the flow of exhaust gases into the intake manifold in controlled amounts. As such, it’s a simple valve that closes and opens as needed. The EGR valve has one single job to do, regardless of the system configuration, type of control and number of sensors: that is, to either open and direct exhaust gases into the combustion chamber, or to close and keep them from entering. Whenever you start the engine, the valve comes alive and waits in a closed position, blocking the flow of exhaust gases. Once the engine reaches operating temperature and speed increases, the valve, either through vacuum or electronic control will gradually open, allowing burned exhaust gases to enter and combine with the air-fuel mixture inside the combustion chamber. When the EGR valve is clogged or dirty, as they are prone to, it may not function properly causing the engine idle rough, stall at idle speeds, cause the car to get poor fuel mileage, or emit a strong smell of fuel due to excess hydrocarbons which also results in failing emissions tests.

A clogged or failing catalytic converter can also cause the vehicle to have poor fuel economy. As you may already know, the catalytic converter converts toxic exhaust gases into less harmful pollutants that are suitable to be expelled into the atmosphere. When this is clogged, this causes these gases to be backed up into the exhaust system not allowing the engine to breathe properly (think of a backed up sink). When this happens, the engine is forced to work much harder to expel these gases. This often results in the engine bogging down, hesitating, shaking and causing very poor fuel economy. I would recommend having a professional from YourMechanic come to your location to diagnose and inspect your vehicle.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

White smoke from unburned fuel vapor smells like raw gas (because it is raw gas), so there`s no mistaking it for water/coolant-induced white smoke. In even rarer cases, a hot muffler or catalytic converter may cause the fuel vapors to ignite, blowing the exhaust system clean off the vehicle.
If the burned oil smell is coming from the tailpipe (bluish white smoke), it is a symptom of oil leaking into the combustion chamber, which means it is getting into your exhaust system. The oil is burned in the combustion process with the air and fuel mixture, and pushed out through the exhaust system.
WHITE OR GRAY SMOKE

White or gray-looking smoke is bad, typically indicating a blown or leaking head gasket. This happens as coolant combines with the fuel and air mixture in your engine`s combustion chamber. A blown head gasket could destroy your engine if left untreated.

Your Chevrolet Impala smelling like gas could signal a gasoline leak which can present a significant fire hazard. Fuel leaks can be hidden in the engine bay and in the undercarriage and may not present themselves as fuel on the ground as gasoline can evaporate quickly.
Bad O2 Sensor

If white smoke pours from your exhaust, it means that vaporized antifreeze will have contaminated one or more oxygen sensors. All fuel-injected cars have these sensors, which are screwed into bungs welded onto the exhaust system.

Faulty fuel injector: Another possible cause of excessive white smoke from the exhaust pipe is a bad fuel injector. The injector can leak or become stuck open and deliver too much liquid fuel into the combustion chamber. The excess fuel causes thick white smoke to be produced and released from the exhaust pipe.
The two most common causes of white smoke coming from the engine are oil leaking and an error in the Engine Control Module. Oil leaking. If white smoke comes from under the hood, particularly from the engine, smells like tar or asphalt, and has a bluish tone – the oil is probably burning inside your vehicle.
White smoke usually means coolant is getting into the combustion chambers of your vehicle. This generally happens because of a cracked or leaking head gasket, which allows coolant to seep into your cylinders. In extreme cases, you will need to replace your head gasket.
Considering that the vent holes are blocked by buildup, the oil does not drain back into the cylinder head. So when you first start the engine, a large amount of the accumulated oil is sucked into the intake system through the vacuum hose. This of course, results in a small cloud of smoke.
White Smoke

It usually means that coolant is being burned in the engine, which means that something is drastically wrong. The most common cause of this is a blown head gasket, which can quickly lead to an overheating engine.

Car Smells Like Gas – Leak in the Fuel System

Take the time to observe when you`re smelling the gas; if you notice the smell while driving and right after you`ve parked, you likely have a leak in the fuel injection line. Schedule service with our Leson Chevrolet Company, Inc.

Fuel Leaks

On most modern cars, fuel injectors located in the intake or inserted directly into the engine itself spray a precise amount of fuel during each cycle. If the seals around these injectors degrade, or a leak develops in a fuel line leading to the engine, you may be able to smell gas.

Here are three indicators of a bad EGR Cooler: White Smoke – while that pesky Valve can cause an abundance of black smoke billowing from the pipes, a failing EGR Cooler actually emits white smoke, or steam, caused by evaporating coolant inside the cooler. When you see white smoke, call for help.
If a bad oxygen sensor disrupts the air to fuel ratio mixture, or too much fuel is injected into the engine, your vehicle`s gas mileage will be reduced. This excess fuel in the engine can produce a sulfuric, rotten egg smell, and may even produce black smoke from the exhaust.
Other reasons for the smoke to be this colour could be a very dirty oil or air filter. However, most of the time the issue is just a problem with the engine (could be internal or external). While white smoke may just come from your engine on a cool day, excessive white smoke most likely indicates a problem.
There are several symptoms that indicate an inefficient fuel injector: Strong gasoline smell.
That`s coolant. That could be head gasket or cracked head or block.
A perforation to your gasket or a blown head gasket usually occurs as a result of an overheated engine. When coolant flows into the combustion chamber from a blown head gasket it burns/evaporates into white smoke.
1: White Engine Smoke

White engine smoke is commonly caused by burning radiator fluid (also known as coolant or refrigerant). You might also notice a sickly sweet smell (often compared to that of butterscotch or maple syrup).

Can faulty spark plugs make your car blow white smoke out of the exhaust? Yes, they can.. Craig Nicol has it right.. Unburned fuel entering the exhaust can light off in the catalytic converter resulting in white, extremely acrid smoke..
If your engine smells of burning or smoke, there are two possible reasons for this: it`s overheating or there`s a problem with the oil. Generally if it`s overheating, you`ll know about it because a warning light should appear on the dashboard.
The most common answer to, “Why is my car smoking but not overheating?” is that there`s a type of fluid that`s landed on the engine. This can be motor oil, fuel, transmission fluid, coolant, or even condensation. It can cause your engine to smoke because it`s burning off that fluid from the engine.
If your car has an exhaust leak, it is not something you want to take lightly. The performance of your vehicle will be hindered. More importantly, it can potentially be deadly for you and your passengers if carbon monoxide and other harmful fumes are leaking inside the vehicle.
The most common answer to, “Why is my car smoking but not overheating?” is that there`s a type of fluid that`s landed on the engine. This can be motor oil, fuel, transmission fluid, coolant, or even condensation. It can cause your engine to smoke because it`s burning off that fluid from the engine.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

I smell gas and it blows white smoke out of the exaust.
ANSWER : Hi There,
There are a number of things that can cause poor fuel mileage. A faulty camshaft position sensor is one of them. The camshaft position sensor is a magnetic sensor that monitors camshaft speed to regulate ignition timing and fuel injection timing. It gathers and sends information about the car’s camshaft speed (and as a result the position of each piston) to the car’s electronic control module. This information is received by the computer, which then uses this data to further calculate the time of ignition and the timing of fuel injection required by the engine. When this is not working properly, you may experience a drop in power, poor idling, poor fuel mileage and problems starting the vehicle.

A clogged or dirty EGR valve may also cause poor fuel mileage. The EGR valve is a small component designed to allow the flow of exhaust gases into the intake manifold in controlled amounts. As such, it’s a simple valve that closes and opens as needed. The EGR valve has one single job to do, regardless of the system configuration, type of control and number of sensors: that is, to either open and direct exhaust gases into the combustion chamber, or to close and keep them from entering. Whenever you start the engine, the valve comes alive and waits in a closed position, blocking the flow of exhaust gases. Once the engine reaches operating temperature and speed increases, the valve, either through vacuum or electronic control will gradually open, allowing burned exhaust gases to enter and combine with the air-fuel mixture inside the combustion chamber. When the EGR valve is clogged or dirty, as they are prone to, it may not function properly causing the engine idle rough, stall at idle speeds, cause the car to get poor fuel mileage, or emit a strong smell of fuel due to excess hydrocarbons which also results in failing emissions tests.

A clogged or failing catalytic converter can also cause the vehicle to have poor fuel economy. As you may already know, the catalytic converter converts toxic exhaust gases into less harmful pollutants that are suitable to be expelled into the atmosphere. When this is clogged, this causes these gases to be backed up into the exhaust system not allowing the engine to breathe properly (think of a backed up sink). When this happens, the engine is forced to work much harder to expel these gases. This often results in the engine bogging down, hesitating, shaking and causing very poor fuel economy. I would recommend having a professional from YourMechanic come to your location to diagnose and inspect your vehicle.

Hello, i had my head gasket repaired and after 8 months it has started making white smoke come from exhaust again and I can smell
ANSWER : Hello, thank you for writing in. With white smoke coming from the exhaust, the smell of coolant, and the (very likely although unmentioned) lowering of the coolant level, it is quite apparent that the coolant is making its way passed the head gasket and into the combustion chambers. Unless you have a cracked head, engine, or other serious damage, the head gasket is very likely the issue. Make sure you are adding coolant to compensate for the loss. Low coolant levels will not give you accurate temperature readings on your dashboard, as the sensor is located at the top and needs to be submerged in liquid to give you an accurate reading. As far as repairing the issue, replace the gasket again, and in the process inspect the old gasket for signs of failure or indications on what caused the leak the second time. If replacing the head gasket again does not solve the problem, you know you have a larger issue with the engine and can take further diagnostics from there. For more help from our technicians, contact our service department to schedule an appointment.

I have white milk coming out of my exhaust pipe but I don’t see it mixing in my oil pan when I check my oil
ANSWER : In most cases, the white smoke is an indicator of coolant finding a way into the combustion chamber. This could happen through a damaged head gasket or a crack in the cylinder head or engine block. Most of the time, this would also be followed by milky oil or overheating problems. However, it could also be a problem with the EGR system, or an extremely rich fuel trim. The best thing to do is have a professional mobile mechanic complete a smoke coming from exhaust inspection, so they can pinpoint the source of your issues and recommend a repair.

Was blowing smoke, bluish white smoke, heavy
ANSWER : Hi there. In most cases, when white smoke blows out of the tail pipe, it’s an indicator of coolant being in the oil and lubrication system. It’s typically caused by a blown head gasket, which could also lead to significant engine damage. It’s best to have a professional mobile mechanic come to your location to complete a smoke is coming from exhaust inspection so they can verify the source of the smoke and recommend the appropriate repairs.

I have a 2002 Jeep Liberty four wheel drive I stopped and got gas I left a they started blowing they started blowing and won’t hol
ANSWER : The problem sounds like you have flooded the carbon canister and the purge valve is stuck open allowing fuel to get into the purge line and be sucked into the engine unmetered. Have the purge valve and carbon canister vent checked and replace vent valve and purge valve. If canister is flooded with fuel then you may have to replace it also.

Car exhaust is giving white smoke when I start the car everyday.
ANSWER : Hi there:

Typically white smoke is an indicator of coolant or liquid other than oil or fuel inside the combustion chambers. This can be caused by a blown head gasket (if you had an overheating issue recently) or simple air to fuel ratio issues caused by a mass air flow sensor or exhaust system sensors not working correctly. The best way to know for certain what’s causing these issues is to have a professional mechanic complete a smoke from engine or exhaust inspection.

Hello when i pump gas there is a strong gas smell and my car also shakes when i crank it upmy car smokes from the bottom when I t
ANSWER : If you are detecting a fuel odor, there is either a vapor leak (EVAP system), or a liquid fuel leak in your fuel system. To resolve that, the recommended service is a fuel leak diagnostic/repair. The smoke is from hot vaporizing oil and/or escaping antifreeze. Transmission fluid is a possibility but engine oil and power steering fluid could be leaking, too. The origin of the leak(s) can be pinpointed if you request a leak diagnostic. If you request these services, the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

White smoke from the engine and smells of rubber with the knocking sound
ANSWER : My guess is that you have a leak somewhere, most likely a coolant leak. Coolant leaking onto a hot engine will immediately result in white smoke. Since you stopped the vehicle before all of the coolant was lost, the vehicle did not overheat. As for the noise, I’m not sure. It could be that the engine fan was running to cool the engine down. Whatever is going on with your vehicle, it sounds quite serious. I suggest you don’t drive it until the knocking sound is inspected by a professional firsthand. YourMechanic is an excellent option since we come to you.