man with engine trouble calling for helpThe engine is at the heart of your car’s performance. As a result, issues are more than an inconvenience – they may prevent the car from working at all and often result in costly repairs.

Multiple systems make up your engine, from the battery to the combustion process, cooling and old fluids that can affect performance. Understand common engine problems and their potential sources.

Engine Won’t Start

When your car doesn’t start, it’s often because the battery has died or needs power. You could also be dealing with a fuel or ignition issue. Potential problems include:

  • The battery has no or a very low charge
  • Ignition switch failure
  • Malfunctioning fuel pump
  • A clogged fuel filter
  • Corroded battery cables creating an insecure connection
  • Insufficient or dirty motor oil affecting performance
  • Catalytic converter failure

Beyond the battery and alternator, aspects like the fuel pump or filter may be interrupting the combustion process. In terms of getting started, a broken ignition switch may have brought the entire chain reaction to a halt. Also, wear on parts throughout the combustion process – from cylinders to piston rings and valves – can affect the compression that drives the engine’s performance.

Engine Misfiring

An engine could also be misfiring due to spark plugs that need to be changed. If the spark plugs seem fine, the air/fuel mixture in the combustion chamber may be to blame. Too much air won’t provide the power your engine needs, while a mixture containing too much fuel can also throw off the process.


Although overheating is more likely to occur in warmer conditions, it’s a risk at any time of the year and typically comes down to the quality or amount of coolant circulating in your engine.

However, the entire cooling system plays a role. If the temperature gauge goes up or notice a warning light on your dashboard, the thermostat, cooling fan, radiator or parts connecting these components may be to blame.

Among these factors:

  • Dirty coolant can cause deposits to form in the cooling system, resulting in clogs that affect its performance.
  • Due to wear and tear or clogs, the radiator may no longer be able to sufficiently cool the engine.
  • Leaks can form within the cooling system, oftentimes from hoses, seals or gaskets. This causes the system to go through coolant at a quicker rate. When the system doesn’t have enough quality fluid, the engine risks overheating and components could fail.


It’s never a good sign when you hear rattling or knocking behind the wheel. Potential sources include:

  • Excess heat and pressure in the combustion chamber, resulting in a repeated pinging sound
  • Changes to the air/fuel mixture
  • Wear on parts like the timing belt or chain, sensors, belt tensioners and bearings, resulting in vibrations or a grinding sound

Oil Issues

Oil provides your engine with lubrication. Without it, metal parts grind against each other, causing debris to build up in the fluid that places additional wear on the engine’s components. The debris may also accumulate on parts like the intake valves and spark plugs, influencing their performance.

Common oil-related factors affecting the engine’s performance include:

  • Low or no motor oil, either through owner negligence or oil pump failure
  • Water in the engine oil
  • Oil oxidation, which can occur from age or excessive heat and results in insufficient lubrication

Sensor Issues

For modern cars, sensors are key to performance, especially where the engine is concerned. While multiple sensors are involved, the oxygen sensor is especially important and may be the primary cause of all existing engine issues.

When this part malfunctions, the air/fuel mixture gets altered. This occurrence affects the combustion process, lessens the power delivered to the engine and can decrease the car’s gas mileage. You may also notice the engine stalling regularly as you drive.


Although a smoking engine can be caused by overheating, a few other factors may be at play:

  • The car is consuming an above average amount of oil
  • Fluids are leaking from damaged seals and rings
  • The engine is not getting enough ventilation
  • The engine is going through coolant fast, which may lead to smoke coming from the exhaust

When you notice any of these signs, bring your car to DaSilva’s for an assessment and auto body repairs. To learn more or schedule an appointment, contact our Naugatuck shop today.