Why Your Engine Cranks But Won’t Start

TIPS OF THE WEEK

By Bennett  Oghifo

When you turn your key to start your car, the repetitive chirping sound the engine makes for a second or two is the starter, turning the engine over so it can begin running under its own power. that sound is called “cranking,” and you want to hear that noise because it means your car’s starter is doing its job. but what if you hear the engine crank and the engine just won’t start and run on its own? That means there’s a problem in the engine itself that’s preventing it from getting started. 

5. Insufficient Compression

In order to start running under its own power, an engine needs four essential things: air, fuel, compression and spark. an engine with low compression can be difficult or impossible to start, and it means seals and gaskets could be leaking in the engine. you may need things like new valve seals, new piston rings or other components replaced so that the engine can withstand the intense pressure it needs to run.

4. Clogged Fuel Injectors

If the car cranks when you turn the key, but the engine won’t start, it could be because fuel isn’t getting to the engine.

One potential reason for this could be dirty fuel injectors. over time, the fuel injector nozzles can become clogged with rust, corrosion or debris. once clogged, the fuel injectors may not add the correct amount of fuel to the cylinders, and the vehicle may not start up at all. To keep your fuel injectors clean and working as intended, be sure to only add high-quality gasoline to the tank. gasoline from less-than-reputable sources that has been improperly stored or transported is more likely to contain damaging debris that could make its way through the fuel lines and to the injectors — ruining them.

3. Bad Fuel Pump

Another reason fuel might not be getting to the engine is a bad fuel pump. most gasoline from chain service stations is perfectly clean and properly stored, so bad fuel injectors aren’t often the problem. you’re even more likely to suffer from a bad fuel pump. If the fuel pump in your car goes bad, gas won’t be able to flow from the tank to the engine, and it simply won’t be able to run on its own. we’ll simply recommend that you have the pump replaced.

2. Bad Spark Plugs

If the engine holds compression well, and the fuel system is working correctly, but it still won’t start, that tells us that your car’s spark plugs may not be working. The spark plugs ignite the air/fuel mixture inside the engine’s cylinders. it’s the resulting explosion that actually powers your car.

Modern spark plugs can last 100,000 miles or more before going bad and needing to be replaced, but they can go bad earlier than that for a variety of reasons: If the engine experiences too much carbon build up, this can foul your spark plugs. or, if oil leaks into the engine, it can coat the spark plugs and prevent them from working. The problem may also be with one of the components, like the computer or the ignition coils, that supply power to the spark plugs

1. Bad Crankshaft Position Sensor

Not only does the engine in your car need a spark to begin combustion, that spark has to take place at the exact right moment. Too late or too early and the air/fuel mixture won’t entirely combust, reducing performance and potentially failing to start the engine entirely. One of the reasons your spark plugs might be firing incorrectly is due to a faulty crankshaft position sensor. It’s this sensor that tells your engine’s computer the position of all the valves and pistons at any given moment.

 The Ecu then uses this information to determine when to fire the spark. If this sensor has gone bad, the Ecu won’t know when to fire the sparks, and the engine might not start.