What is the P0308 fault code and what does it mean? What is the Cylinder 8 Misfire Detected description? How do I fix the P0308 fault code What are the symptoms and causes for the P0308 fault code
What is the P0308? What is Fault Code What does it signify?
For an engine to work properly, it needs three things: compression, ignition, and the right air/fuel mix. The root cause of a misfire in one of the engine cylinders is an issue with one of these three elements.
The engine will be damaged if one or more of the cylinders fail to fire. A code P0308 will be issued if the powertrain control module, PCM detects a misfire on cylinder 8.
To detect a misfire, the PCM collects information via the crankshaft position sensors (and sometimes from the camshaft positioning sensor). The PCM monitors the crankshaft rotational speed of each engine cylinder. The module uses this data to detect misfires in each cylinder.
The cause of misfires is incomplete or insufficient combustion. An internal engine problem or faulty ignition coil could be the cause.
P0308, which is an indication of a cylinder 8 misfire (also known as P0300 to 03.12), can be correlated with other engine misfire codes such as trouble codes P0300 or P0312.
What causes the P0308 Fault code?
Engine misfires can result in a wide range of problems and can be caused from many different factors. Here are some possible causes.
- Faulty sparkplug in 8th Cylinder
- – The 8th cylinder is not compressed.
- – Sparkplug wires worn or damaged
- – Ignition coils that are worn or damaged
- – Defective distributor cap for some vehicles
- – Defective delivery roll (some vehicles).
- – Defective fuel injector
- – EGR valves or EGR pipes clogged
- – Valves that have been melted or burned
- – Misfire timing
- – Vacuum leaks
- – Low fuel pressure
- – Leaky head gasket
- – Defective camshaft sensor
- – Defective crankshaft sensor
- Sensor for defective mass air flow (MAF).
- – Defective oxygen (O2) sensor
- – Defective throttle positioning sensor
- – Defective catalyst converter
- – Fuel injector circuit problems
- – Internal engine problems such as worn camshaft lobes
- – Defective PCM
What is the P0308? What are the Fault Code Symptoms
Below are some symptoms that code P0308 can cause. These symptoms may be combined.
- Depending on the severity of the misfire, check that your engine light is on or flashing.
- – Engine running very hard or not at all
- – Engine hesitation during acceleration
- – Engine stops at idle
- – Insufficient engine power
- – The engine is jerky to operate
- – Irregular idle velocity (fluctuations).
- – An increase in fuel consumption
- – Exhaust fuel smell
The check engine light will flash continuously if the crankshaft speed changes between 2-10% and 2-20%. The check engine light will continue flashing if the crankshaft speed is greater than 10%. A crankshaft speed variation of more then 10% can indicate a serious misfire condition.
How to Fix the P0308 Fault Code
- Repairing damaged or defective spark plugs
- – Replacing damaged spark plug wires
- Repair of faulty ignition coils or cables
- – Replacing distributor or distributor roller, if applicable
- – Repair or replacement for an EGR valve blocked
- – Repair or replacement EGR pipes clogged
- – Repair of damaged or faulty valves
- – Replacing head gasket
- – Replacing the defective sensor on the camshaft
- – Replacing the defective crankshaft sensor
- – Replacing the defective MAF sensor
- – Replacing the defective oxygen sensor
- – Replacing a defective throttle position sensor
- – Replacing a defective fuel injector
- – Replacing the defective catalytic converter
- If necessary, diagnose and repair any other fault codes
- – Repairing internal engine parts if necessary
- If the cylinder is damaged, the engine will need to have its components replaced.
- – Repair or reprogramming the PCM as necessary
All spark plugs need to be replaced if one spark plug is defective. Ignition failure can also be caused by spark plug gaps. Spark plug gaps should conform to the manufacturer’s specifications.
To diagnose a defective ignition coil, it is best to move the coil and then check to see if misfire spread to other cylinders. The ignition coil is responsible in such cases.
How serious is the Fault Code P0308?
Fault code P0308 can be a serious problem. This code is stored in the powertrain controller module and can cause the engine to stop running. An engine that is not working properly can cause the vehicle to stall or stop starting. The driver could be left stranded at the side of the road as a result. It’s best to identify the source of the problem and get it fixed as soon as possible.
