What would cause engine light flashing - 2008 Hyundai Tucson

have it scanned for trouble code

You most likely have a non firing cylinder causing the shake and the raw gas from the non firing cylinder is going into the catalytic converter.It is detected and causing the flashing check engine light.
A flashing check engine light means REPAIR NOW!

You did not post the year make and model BUT you should not drive the vehicle because when the check engine light flashes, you can cause damage to your engine. You need to get an OBD reader from a chain autoparts store and see what codes are present.

P0304 is engine misfire #4 cylinder Several things can cause a misfire #1 electrical which you have covered #2 Mechanical Test engine compression is should be around 150 cranking and 120 running . internal valve train components can cause bad compression and the valves then self. #3 fuel injector can be the cause suggest swapping with a know good cylinder and see if misfire follows injector.

it's possible. The water can cause misfires in the engine. when the light flashes that means you are causing damage to the engine.

Dont drive a car with the light flashing. A flashing check engine light means that something is really wrong and you can damage the engine if you drive it.

Your vehicle has hundreds of electrical circuits. The wires for these circuits are bundled together in what is called a wiring harness. The engine wiring harness is the bundles of wires that go to the electrical components of your engine.

Damage to a wiring harness can cause all kinds of electrical problems that can affect everything from how your engine runs (or fails to run) to how your lighting or entertainment systems work.

Yes, a damaged wiring harness could possibly be the cause of the problems you are describing with your vehicle. It could also be a lot of other things. That is what DIAGNOSIS is for. If your check engine light is flashing, it is because your engine control system needs to be diagnosed to determine what is causing the problem with your car that is causing the light to flash. The check engine light means pretty much what it says: CHECK YOUR ENGINE, or more acurately, your engine control system.

Why Is My Check Engine Light Flashing? Location

1. The check-engine light may be a graphic of an engine or similar icon, or it may contain the words "check engine" or "service engine." In some vehicles, a red check-engine light means the car needs absolute immediate attention while a yellow check-engine light means you need to make an appointment soon. Either way, you should know the location of the light and periodically glance at it to ensure its status. The light is used to indicate power train problems that are associated with your vehicle's emissions system. (The power train is the engine, transmission and other power parts of your vehicle.)

Flashing Light

1. Typically, a flashing light is more serious than a solid check-engine light. The flashing light is meant to alert you that you may have a misfire in your engine that will cause catalytic converter damage if you leave the problem unresolved. Replacing a catalytic converter can be costly, so have the engine checked as soon as possible by a certified mechanic.

Cause

1. A flashing check-engine light generally indicates that there is a failure in the emission control system. The emission control system contains an array of sensors that work to reduce the amount of pollution released into the air. An oxygen sensor reads the air and fuel mixture and lights up when it is out of range. The acceptable range is between 50 mill volts and 800 mV. If the check-engine light is flashing, you should visit your mechanic or dealer as soon as possible.

Loose Gas Cap

1. A gas cap that isn't twisted on tight enough may cause the check engine light to illuminate, but it won't flash. Try tightening the gas cap and watch the light. In many cases, it will turn off because the problem has been corrected. If the light stays on for more than a day or two, have your mechanic run an on-board diagnostic (OBD) to see if there is a code in the system indicating a serious problem. Your mechanic can reset the light to off if the problem was a loose gas cap.

Spark Plug Wires

1. As spark plug wires age, they can become brittle and crack, causing an electrical misfire. Your check engine light might turn on and stay lit. If this happens, go home as soon as possible, turn off your engine, and inspect the wires. If the wires are brittle and cracked, you need to replace them. If your check engine light stays on after the wires are replaced, have your mechanic run an OBD.

Have the car scanned for the code's origin. This could mean that the engine will not work as well as it should, and could cause driveability isues.

A constant service engine soon light means that a hard code exists. A flashing light means that an intermittent code exists, but it could become a hard code very quickly.

flashing check engine lights mean that there is a critical failer that could cause severe damage. they should not be taken lightly. a missfire can cause the light to flash. the best thing to do is take car to a shop or an auto parts store to get the check engine light read. check engine lights dont always tell you exactly what is rong, but this will give a good direction to start in. a check engine code would be helpfull in diagnoseing the cars problem.