Bad 5th cylinder - misfiring?

Bad 5th cylinder

Does it need valve job or piston work

My car has 175000 miles.

Experienced mechanics share their insights in answering this question :

It is unlikely that your motor needs a valve job or piston work judging by the amount of miles, absent some kind of catastrophic failure inside your motor. Often times, engines will have misfires for a wide variety of reasons that can cause a "dead cylinder" problem.

Engine misfires can be caused by a list of problems, but there are a few suspects that occur more than others. Generally, misfires are caused by either a spark or fuel issue or in cases, a combination of both. Spark related problems generally will result from things like ignition coils, crankshaft position sensor, spark plugs, spark plug wires or ignition modules not working properly. When the misfire results from a fuel related issue, this is commonly related to a lean fuel condition (lack of sufficient fuel supply to the motor).

Fuel related misfires can be caused by many different things such as low fuel pressure, faulty or dirty fuel injectors, a faulty O2 sensor, a dirty or failing mass air flow sensor, a faulty or dirty idle air control valve or a vacuum or intake leak. When the fuel supplied to the combustion chamber is insufficient, this results in an ignition (spark) that is igniting a less than balanced load of fuel and air. This results in a misfire or an explosion in the cylinder that is much less powerful than the other cylinders. This creates a loss of power that resonates throughout the motor additionally causing other problems with ignition and fuel timing. I would recommend having an expert from YourMechanic come to your location to diagnose your misfiring problem.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

A P0305 cylinder misfire can occur for a multitude of reasons, right from a faulty spark plug and fuel system errors to internal engine damage. That said, the most common reason for a cylinder 5 misfire is a worn-out spark plug, ignition coil, or coil pack.

A misfire typically occurs when the timing of this ignition is off. P0305 indicates that cylinder #5 is experiencing misfires.

Common causes include ignition system troubles, fuel delivery issues, or leaking valves. However, a faulty or worn-out spark plug or ignition plug coil pack is the most common cause of the misfire. This is especially true if your car tune-up has been delayed for a while.

The P0305 error code indicates a severe engine problem. Do not drive when a misfire is active; it will cause further engine damage and increase repair costs. Not to mention the decrease in fuel economy and performance. Immediately take your car to the mechanic to avoid catalytic converter damage and ignition failure.

If an oxygen sensor or mass airflow sensor is failing, it could give incorrect data to your engine`s computer, causing the misfire. When a vacuum line is broken, it can cause a fuel-injected motor to misfire.

Engine misfires happen when one of the cylinders does not produce sufficient spark or compression and lack of fuel. It could involve more than one cylinder. It can be caused by a faulty spark plug, fuel injector, ignition coil and or worn cylinder.

The P0455 diagnostic trouble code appears when there`s a leak in the Evaporative Emission Control (EVAP) system, and the system can`t maintain pressure. The EVAP system usually consists of five main components: the fuel tank, fuel cap, vent valve, purge valve, and the evaporative canister (or charcoal canister).

The most common causes of misfires are worn, improperly installed, and mishandled spark plugs, malfunctioning ignition coils, carbon tracking, faulty spark plug wires and vacuum leaks.

For example, the issue can stem from a faulty spark plug or wire, which in the grand scheme of things is relatively easy to repair. However, the error code may also occur because of a faulty catalytic converter or defective computer system, which can vary in expense.

The type “A” misfire is the most serious condition and indicates impending catalyst damage. If detected, the Malfunction Indicator Lamp (MIL) may flash once per second to alert the driver that immediate service is required.

An engine misfire is when one or more cylinders doesn`t produce power, and there are several possible causes, from a fouled spark plug to a clogged fuel injector or faulty oxygen sensor.

Even a dirty MAF sensor can cause a lean code and/or misfire to occur. The engine may be stalling because it isn`t getting enough throttle opening.

Misfire at Idle Only. Your car may drive perfectly fine but display signs of little hiccups or small misfires at idle. Generally, the cause of a misfire at idle is an incorrect air-fuel mixture. This can be caused by a faulty O2 sensor, a fuel injector that needs cleaning, or even vacuum leaks.

Vacuum leaks, especially those that are confined to one cylinder, will cause the engine to idle unevenly and possibly misfire. This is because the vacuum leak allows additional air to reach the affected cylinder, diluting its air/fuel mixture.

Normally the misfire counts should be zero or close to zero for every cylinder. The OBD II system will usually NOT set a misfire code until the actual misfire count exceeds about two percent for any given cylinder.

What the P0305 code means. P0305 is a generic OBD-II code that the engine control module (ECM) detected a misfire on cylinder number 5 of the engine.

The catalytic converter may certainly cause the P0300 random misfire code to show up due to the inability for the exhaust to properly breathe, which can cause un-burnt exhaust gases to reignite inside the catalytic converter. A clogged or failing catalytic converter can cause the vehicle to have poor fuel economy.

Any raw fuel in the catalytic converters quickly overheats them and leads to their destruction. If misfires occur severely then damage occurs quickly. If misfires are subtle, then damage may not occur for a year or two.

What causes the P0455 code? The leak can be caused from a variety of components. The most common is related to the fuel filler cap which could be missing, not correctly installed, not sealing properly or may be damaged to the top of the filler neck. The next most frequent problem is a leak in a hose.

You may drive your vehicle while trouble code P0455 is present unless the gas vapor odors are very strong or you see obvious fuel (liquid) leaks. Extreme danger, seek repairs if either of these two scenarios exist. Note, a large fuel vapor leak may cause fuel economy issues.

Yes. While the damage may seem small initially, the longer you drive with a bad oxygen sensor, the worse the damage will become. Eventually, you may experience rough idling, poor acceleration, engine misfires, an illuminated check engine light, and failed emission tests.

Common Symptoms of a Faulty Coil Pack

An unexplainably louder-than-usual engine. A noticeable lack of power. A significant drop in RPMs while accelerating for no apparent reason. A blinking or intermittently activating check engine light.

Catalytic converter problems cause gas within your engine to heat up to the point that it actually ignites. This ignition is what causes the misfiring sensation – and that can destroy engine components. Anytime your vehicle misfires, you should have it checked out by a reputable service professional.

Driving with A Failed Catalytic Converter

If you`re noticing slow powertrain performance, reduced acceleration, a smell of rotten eggs or sulfur from the exhaust, dark exhaust smoke, or extreme heat from under the vehicle, these are symptoms of a clogged Catalytic Converter, and it should be replaced quickly.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Code said cylinder 1 misfire, cylinder 2 misfire, o2 sensor misfire?

ANSWER : Without checking the ignition coils and spark plugs myself for proper spark output I would say the engine is misfiring and may be the coils and plugs. It is also common for the valve cover gasket to leak oil into the spark plug tubes shorting the coil and spark plug out so it cannot fire. The check engine light is flashing due to the misfire is active and additional catalyst damage can happen if you keep driving with the misfire and raw fuel dumping into the catalyst. I would recommend having a mobile mechanic like one from YourMechanic come and do a through diagnosis to see if the valve gasket is leaking into the spark plugs and caused damage to the coils and spark plugs. If it is leaking then the valve cover gasket should be replaced with the spark plugs and contaminated ignition coils replaced then computer codes an be cleared and the vehicle road tested for any other problems from driving the vehicle with the engine misfiring.

Read Full Q/A … : Bad 5th cylinder

Rough idle, possible misfire, bad oxygen sensor a possible cause

ANSWER : There are a number of things that can cause a misfire to be present, but a failing oxygen sensor is certainly one of them. As you know the oxygen sensor reads the exhaust gases and relays this information to the computer which then makes adjustments to the fueling of the motor. When this is not working properly, this may cause inaccurate readings to be sent to the computer resulting in improper fueling adjustments to be made. This will no doubt cause an erratic idle and in some cases cause a misfire depending on the adjustment made. I would recommend having a professional from YourMechanic come to your location to diagnose and inspect your truck.

Read Full Q/A … : Bad 5th cylinder

What would cause 1st cylinder misfire, multiple misfire, all fuel injectors circuits open and o2 sensors heater circuit high on a 2008 Dodge Charger

ANSWER : Hello. It sounds like you may have the wrong parts installed on the car. Due to the fact that multiple people have worked on it you may have some parts that do not meet specifications. From what it sounds like to me though you either do not have an ECM in the vehicle with the correct programming or you have a connection issue. If all of the grounds are not clean and tight then that will cause this. if they are then the computer needs to be programmed to your vehicle at the dealer and that may take care of it.

Read Full Q/A … : Bad 5th cylinder

Keep getting multiple misfire codes, normally different cylinders except on cylinder (0307), can this one be throwing off the rest

ANSWER : This may be a problem with the exhaust catalyst partly clogged causing excessive back pressure. There is a test where the O2 sensor is removed and the back pressure tester is put in the hole to see if the catalyst is clogged.

The computer should be scanned to see if you are running lean from bad O2 sensors or for some other reason. The coil may also be weak and not putting out enough spark energy. Have the system checked by a mechanic since this truck engine may have exhaust problems, engine carbon build up, cracked valve seats, O2 sensor problems, coil problems, camshaft and distributor cam gear worn problems. The list goes on and will require a qualified mechanic time to diagnose this complaint for you. If a shop or mechanic cannot figure it out then it may take a factory trained mechanic to be able to diagnose the problem down to one of the listed issues. The best thing to recommend is to replace all the tune up items first so these can be eliminated. This means coils, plugs, wires, fuel filter and air filter, and PCV valve.

Read Full Q/A … : Bad 5th cylinder

Misfire on cylinder one

ANSWER : A misfire to cylinder 1 may be a fuel pressure regulator sensor problem but it is most likely due to a clogged injector on number one. You will need to scan and view data to see if fuel pressure sensor is needing replacement first. Then have the injectors cleansed to see if the codes go away.

I’d suggest you get this looked at by a qualified technician who can perform these checks to diagnose your Check Engine Light and make the appropriate repairs to your vehicle.

Read Full Q/A … : Bad 5th cylinder

Car misfiring on cylinder three

ANSWER : Hello! We will be happy to assist. You have definitely been on the right path to finding the root of the misfire. However there are a few things left that I recommend checking. I suggest to check the spark at the spark plugs at each cylinder. There may be an issue with the coil pack causing the misfire. Also check the PCV valve because that is a known cause of a misfires on your particular vehicle. I suspect that the PCV valve and hose may be leaking and causing the misfire.

You may have the engine model which has the PCV valve located above the transmission next to the exhaust header. This engine model’s PCV valve is routinely looked over because most are unaware that there are two PCV valve systems and the first one is easily visible from the top. I also recommend checking the resistance and voltages at the coil packs with a multimeter. I have a friend whom worked as a technician at a Ford dealership once tell me of a problem with your generation of Focus in which the wiring to the coil packs were made too tight and the tension broke the wires overtime.

I would always recommend having a qualified mechanic, such as one from YourMechanic, assist you in diagnosing your engine misfire and assisting you in repairs.

Read Full Q/A … : Bad 5th cylinder

If cylinder 3 misfires is that a bad thing?

ANSWER : Hi there. A misfiring cylinder can be expensive if allowed to continue. The catalytic converter can be damaged. If the cylinder is misfiring, the coil, wire, and/or spark plug could be the cause. First swap the spark plug between cylinder 3 and one of the other cylinders. Make sure to note which ones you swapped. Check to see if the misfire moves from cylinder 3 to the other cylinder. If this is the case, then replace the spark plugs as the swapped plug is at fault.

If there is no change, then the wire or coil may be at fault. Wire and coil resistance can be checked with a digital volt/ohm meter and compared to specifications. If you would like to have a professional take a look, a certified technician from YourMechanic can come to your car’s location to diagnose the misfire and follow through with appropriate repairs.

Read Full Q/A … : Bad 5th cylinder

My engine light is on, has increased emissions and reduced power, and car also shakes

ANSWER : Hello, thanks for writing in. The coolant temperature code can be due to low coolant or a failure in the thermostat. Most of the time this is a thermostat issue. As for the misfire problem, it is common for one or more coils to fail and cause this to occur. I usually test each coil to see if any of them are marginal. Many times on these vehicles just to prevent having continued issues with coils I change them all with the spark plugs if there are a lot of miles on the vehicle. I also do a compression test to make sure that the engine is fine internally. If there are multiple cylinders misfiring I also do a fuel pressure test because low pressure will cause this to occur. If you are looking to have your misfire and temperature codes looked at, consider YourMechanic, as a certified mechanic can come to your home or office to inspect this and make or suggest how to proceed with repairs.

Read Full Q/A … : Bad 5th cylinder