Q: My car is emitting black smoke and has poor acceleration

asked by on March 16, 2017

My car jerked real hard months ago when i put it in drive, i heard a loud clunk. Ever since then, i have had sluggish acceleration when taking off. Recently, i noticed when i push on the gas, black smoke comes out of my exhaust pipe, it doesnt come out while driving, just when i push on the gas.The acceleration is still weak. Also, if i drive it for more than 30-45 mins (usually on a hot summer day) the temperature gauge goes up and drops. But it doesnt always drop, it sometimes stays up there. Please help me figure out whats wrong with my car. Im getting more spark plugs and wires installed soon, hoping that will solve something.

My car has 129947 miles.
My car has an automatic transmission.

Hi There, 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.

Your issue regarding the temperature gauge seems to indicate you have a faulty thermostat. The thermostat regulates the flow of the coolant in your car’s engine and controls when the coolant flows in and out of the motor from the radiator by opening and closing at specific temperatures. When your thermostat is not working properly or is stuck closed, this will not allow the coolant to properly circulate through the engine, which may cause the engine temperature to fluctuate erratically or in some cases just remain hot. When the thermostat is stuck open it can cause the coolant to circulate constantly resulting in the motor never reaching the correct operating temperature. I would recommend having an expert from Your Mechanic come to your home to diagnose your vehicle.

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