Q: Black smoke pouring from exhaust

asked by on February 28, 2017

I have just started my car this morning and the weather is -6 and the car thankfully started first time within 2 seconds which was good unfortunately i noticed a big puff of black smoke coming from the exhaust which lasted for about 5/6 seconds then went away what could the issue be? My car is a ford Sierra and has only done 4900 miles and has recently been serviced before christmas

Fuel Injector Replacement $400.56 - $3968.30 Get a Quote
Mass Airflow Sensor Replacement $188.36 - $786.53 Get a Quote
Fuel Pressure Regulator Replacement $126.81 - $1011.90 Get a Quote

Black smoke coming from the exhaust is usually an indication of a rich fuel condition. When this happens, this can be the result of many things such as faulty fuel injectors, a failing mass air flow sensor or a faulty fuel pressure regulator allowing too much fuel to be supplied to the combustion chamber to be burnt. When this happens the result is an excess amount of unburnt fuel being passed through the exhaust coming out in the form of black smoke. I would recommend having an expert from Your Mechanic come to your home to diagnose your fuel system.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Car won't accelerate and warning light flashing.
The flashing light you are seeing is most likely your Check Engine Light. When the Check Engine Light is solid, then this is letting you know that there is a problem with the emissions system in your vehicle. When the...
Car stalling when turning on the AC.
A stalling vehicle when the AC or Defroster is activate indicates a problem with the compressor. It is either seized/hard to rotate or the AC refrigerant is overcharged preventing the compressor from turning. This will also put increased load on...
Code p0140 we replaced 02 sensor and catalatyic converter
The vehicle should have an original equipment HO2S not aftermarket generic. For a P0140 code (https://www.yourmechanic.com/article/p0140-obd-ii-trouble-code-o2-sensor-circuit-no-activity-detected-bank-1-sensor-2-by-jay-safford), the wiring harness should be closely inspected for damage: chafing, pinches, melting, or water intrusion into connector. Exhaust leaks upstream of the HO2S must...
Lose rpm and hard to start. I have a code p0336 that is read on a scanner.
Hi there. The code for P0336 (https://www.yourmechanic.com/article/p0336-obd-ii-trouble-code-crankshaft-position-sensor-a-circuit-range-performance-by-jamahl-walker) is referring to the crankshaft position sensor loosing a signal to the computer. I recommend replacing the crankshaft position sensor and it should fix all of your problems. If you need further assistance...
Air hissing sound - 2002 Kia Spectra
Hi - air hissing sounds (https://www.yourmechanic.com/question/hissing-sound-by-jimmy-f) like you describe could have several causes. A leak in the engine intake system, a leaking power brake booster (brake pedal harder to press?), or something rubbing on the engine accessory belt can all...
P065A - Generator System Performance
Hello, thank you for writing in. To start, the generator is the alternator. It generates the power supply for the vehicle based off the vehicle's engine performance. There are several ways to approach the repair. You may remove the starter...
Lost hose below two heater hoses and unable to find proper name for hose to replace it. Can you assist?
Hi there. The hose that you are describing sounds like the heater core by-pass hose. If the hose is short and straight, then it would be the heater by-pass hose. The heater by-pass hose it to by-pass the heating system...
Why does my car keep dying on me?
Hi there. I think your best option here is to have a professional mobile mechanic come to your location and complete a car starts then stalls inspection (https://www.yourmechanic.com/services/car-starts-and-then-dies-inspection). In most cases, if you suspect a PCM or ECU issue is...
2000 Mustang v6 manual has whining sound coming from the power steering pump even after replacing the rack and pinion, pump & HPL
If you haven't already done so, disconnect the drive belt to the pump and briefly run the engine to be sure that the noise is not coming from elsewhere. If indeed the noise is from the pump, be sure you...

Related articles

How to Buy Good Quality Sensors
Sensors Sensors for autos have many of the same characteristics that other types of sensors do – they are created to detect a signal, respond to chemical or physical variations such as distance or temperature. These signals are then converted...
Symptoms of a Bad or Failing EVP Position Sensor
Common signs include poor cold start performance, the Check Engine Light coming on, and failing an emissions test.
How Long Does an Air Charge Temperature Sensor Last?
The The air charge temperature sensor, also referred to as the intake air temperature sensor, works to monitor the temperature of the air as it enters your car engine. The engine’s computer has to have this information so it can...