What To Check When Your Engine Cranks And Refuses To Start


Your vehicle’s engine may refuse to operate as expected for several reasons. The culprit is always related to the three things your engine needs most: fuel for combustion, sufficient compression within the cylinders, and a spark. Without all three, the engine will not perform as it was designed. The problem is, each can be affected by other parts and systems, making it difficult to diagnose the root cause of a problem.

In this article, we’ll focus primarily on the factors that can cause your engine to crank (i.e. turn over), but not start. We’ll begin with the items that are easiest to troubleshoot, and advance to the more difficult items toward the end.

Inspect The Fuses First

This step sounds intuitive, but a lot of people neglect to do it. Whenever you’re experiencing issues with components that rely on your vehicle’s electronics, check the fuses before anything else. The reason cars have fuses is to protect the electrical circuits from an overload. If a particular fuse burns out, the part or assembly controlled by it will stop working. This includes your engine and parts that influence its operation.

Look in your owner’s manual to find out which fuses affect your engine. Then, open the main panel, remove the fuses, and inspect them. If the links inside are broken, the fuses are bad. If the links are intact, they are fine.

Pull The Trouble Codes

When your engine experiences any deviation from its normal performance, it will produce an OBD-II trouble code. This code is logged into your car’s computer. This allows a mechanic to retrieve it and have a better idea regarding where to start looking for the root cause of the deviation. If you have an OBD-II scanner, you can pull it yourself. You can purchase a scanner at many auto supply shops for less than $40.

Pulling codes from the computer is easy. A diagnostic connector is usually located in your vehicle’s cabin underneath the dashboard. You can plug the scanner into this connector in order to pull the codes from the computer. These OBD-II codes are alphanumeric (e.g. P1086, P1822, etc.). Once you have pulled them, look for their definitions online. This may provide helpful clues regarding why your engine refuses to start.

Examine And Test The Spark Plugs

Recall that one of the three things your engine needs is a spark. Hence, each cylinder has a spark plug (sometimes, two) that ignites the compressed air-fuel mixture within each cylinder’s combustion chamber. This results in a mini-explosion within the chamber. The explosion produces vapors that expand rapidly and push the piston downward, which turns the crankshaft.

Unfortunately, spark plugs become fouled over time. Deposits can accumulate on them and make it difficult to generate a sufficient spark. This can cause your engine to crank, but refuse to start properly. If the spark plugs appear fine, it’s time to test the pressure within the assembly.

Check The Combustion Chamber’s Compression

In order for the air-fuel mixture to ignite within the cylinder, it must be sufficiently compressed. This means the cylinder should be free of severe compression leaks. Often, the exhaust valve will fail to close properly, and thus allow air to escape during the combustion process. If a leak is severe, it can prevent your motor from starting.

You can purchase a compression gauge for less than $40. If the compression within the cylinders is fine, you’ll need to test your ignition system.

Is Your Ignition System Operating Properly?

There are several components that comprise your ignition system, and a failure that affects any of them can impair your engine’s performance. These include the spark plugs, distributor and distributor cap, rotor, ignition coil, and other pieces. Unless you’re experienced with automotive diagnostics, it’s a good idea to have a mechanic test these parts.

If your engine cranks, but will not start, follow the troubleshooting guide above. If you are able to isolate the problem to the fuses or spark plugs, you’ll be able to easily resolve it on your own. Selling the car off is not always a good idea but getting the engine fixed is much better and cheaper option. If the engine is having some problems that to which you need to replace some parts or the entire engine, be sure to spend some time looking for the right option. Read other Ideal Engines Review on their engine replacement experience. It is not obligatory to open the whole engine up and overhaul it thoroughly; reasons may vary engine to engine for the reconditioning.

If the engine has worn out due to the excessive usage, it may require to be rebuilt in order to increase its durability and boost up the performance. Or it may need reconditioning for finer looks and smoother operations. There are some professionals, highly trained in reconditioning of engines, who make it so smooth that you wonder if that was the same engine you had given to them. Bear in mind one thing though, engine reconditioning, every so often, does not work out as anticipated.

Nevertheless, if you love your car so much and willing to keep it for long, the better is to opt for an engine replacement rather than engine reconditioning. Question may rise why not go for a reconditioned engine? Why go for a replacement engine anyway? The answer to all these questions is that in reconditioning the engine, plenty of efforts are put in to give it a good finish and make it look like a new one. Whereas, a fewer parts are replaced or reworked to give the engine a longer life and better performance. It comes with the satisfaction of the owner for all the money paid.

On the other hand, when opting for an engine replacement, the whole engine is rebuilt and reworked for optimal performance and even longer life with smoother ride. The cylinder head and engine block is worked to match the adjustments of polished and machined crank shaft. An appropriate oil pressure is maintained by the installation of bearing sets and flat mats in main journals and connecting rods. After fitting the new pistons, the cylinder head and chambers are pressure tested for internal cracks thus creating a positive seal. The last thing done is the installation of new oil seals to ensure they keep the pressure up and are tight enough to hold the oil in.

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