2012 audi a4 quatro, cylinder 2 misfires
2012 audi a4 quatro, cylinder 2 misfires, replaced cylinder 2 coil, replaced all spark plugs, 2nd cylinder fuel injector, cleaned carbon off the valves, replaced oil separator assembly, compression test reveals cylinder 2 at 130 vs 1 3 and 4 at 170, misfires at idle only, Please help
My car has 71500 miles.
My car has an automatic transmission.
Experienced mechanics share their insights in answering this question :
The variance in cylinder compression you are reporting exceeds that allowed in the Factory Service Manual. Put oil in the No. 2 cylinder to see if compression rises appreciably and you can then rule in or out leaks past the rings (the oil has the effect of sealing the rings). If compression is not higher with oil, the head gasket and/or valves are leaking and that may be a part cause of the misfiring. If those components are leaking, the engine will have to be repaired. There is always a possibility of an electrical fault in the injector circuit, so you can evaluate that and, as well, look at the secondary firing pattern in cylinder two which will provide clues as to what exactly is going on in that cylinder. If you desire a more conclusive diagnostic, please request a misfiring diagnostic and the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.
How to Identify and Fix Common car Problems ?
Our sources include academic articles, blog posts, and personal essays from experienced mechanics :
What causes an engine misfire? Although there are numerous reasons why an engine might misfire, the culprit is more often than not failure of the ignition coil or spark plugs. These parts experience wear and tear like any other part of your vehicle, and require regular replacement.
Dirty, Faulty Spark Plugs
A faulty spark plug is one of the most common causes of a misfiring engine. Spark plugs are directly responsible for providing the spark that ignites the fuel-air mixture, so their performance is critical in engine performance.
Carbon build up on the intake valves of your VW or Audi 2.0T FSI engine is inevitable. Generally when it happens it will start with misfire codes sporadically when the car is cold(or has been sitting for a while). These are often called cold start misfires and will likely get slowly worse over time.
Audi A4 P0300 indicates that two or more cylinders are experiencing misfires.
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.
The majority of the time, a misfire is caused by a faulty spark plug or another problem with the spark system, but it may also be due to: A fuel delivery problem. A mechanical engine failure. Exhaust gas recirculating.
Low fuel pressure can lead to engine misfires, low acceleration, rough idles, and engine stalls. If your check engine light is on and your car has been stalling out, you may have a fuel pump failure.
Fuel-related misfires can be caused by incorrect atomization of the fuel by the injector. Fuel-related misfires can be caused by bad fuel. In some cases the customer will not bring the vehicle in with an initial problem, but when additional issues occur.
Worn or fouled spark plugs are one of the most common causes of engine misfires. These small but crucial components deliver the spark that ignites the fuel in your engine. If they`re not working properly, your engine won`t be firing on all cylinders.
P0300 Random, Multiple Misfire Detected means that your car`s computer (PCM) detected that there is a misfire in random or multiple cylinders. Code P0300 is often related to bad spark plugs or spark plug wires but could be caused by a number of issues relating to ignition and the air-to-fuel ratio in the cylinders.
What Are the Symptoms of a P0300 Code? Seeing that your check engine light has come on is the most common symptom of any powertrain-related code that indicates a cylinder misfire, while a severe misfire that has the potential to damage the catalytic converter will cause the check engine light to flash.
Symptoms. The signs of a leaking turbocharger system start with a lack of power or random misfires.
Use a spark plug socket to remove the plug to get a good look at it. The damage you see will help you determine the cause of the misfire. If the spark plug is just old, replacing it may solve the problem. Make sure to replace and properly gap new spark plugs.
Misfires don`t simply go away – they need to be addressed immediately. Even if they don`t get worse, they certainly won`t get any better unless you take the car to a mechanic.
This could be failed ignition coils, an open circuit in the wire harness, a faulty ECM, or a mechanical concern. I suggest having a qualified technician perform an inspection to avoid replacing unnecessary parts. Your Mechanic has several available technicians that can assist you with an engine is misfiring inspection.
Multiple reasons could trigger a code P0302 misfire, including a faulty spark plug, a bad ignition system, or a defective fuel injector.
P0302 Diagnostic Theory for Shops and Technicians
When the code P0302 is set in the Powertrain Computer, it means that the Misfire Monitor has detected more than a 2 percent variance in RPM between the firing of any two (or more) cylinders in the firing order.
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.
In a modern car, all of the engine management devices (such as the air flow sensor and ignition coil packs) are connected via electrical circuits. If these connections are not working properly, this could result in incorrect information being fed to the engine management system, causing a misfire.
Typically, engine misfires can be caused by a variety of factors, including malfunctioning coils, worn or faulty spark plugs, a leak or a faulty ignition switch.
A clogged or failed exhaust gas recirculation or crankcase ventilation valve or faulty oxygen sensor can send the wrong signals to the computer and cause misfires.
The fault codes usually associated with a clogged fuel injector can range from misfire codes to lean codes. Fault codes associated with a clogged fuel injector are the P0300 thru P0308 series, which indicates the engine controller is seeing an engine misfire.
If the P0300 trouble code still persists, there could be a problem with the PCM. This may require replacing or reprogramming.
If your car is showing the P0300 engine code, you are dealing with a cylinder misfiring issue. This code is serious, and you should have your vehicle inspected as soon as possible to avoid damage to your catalytic converter.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
2012 audi a4 quatro, cylinder 2 misfires
ANSWER : The variance in cylinder compression you are reporting exceeds that allowed in the Factory Service Manual. Put oil in the No. 2 cylinder to see if compression rises appreciably and you can then rule in or out leaks past the rings (the oil has the effect of sealing the rings). If compression is not higher with oil, the head gasket and/or valves are leaking and that may be a part cause of the misfiring. If those components are leaking, the engine will have to be repaired. There is always a possibility of an electrical fault in the injector circuit, so you can evaluate that and, as well, look at the secondary firing pattern in cylinder two which will provide clues as to what exactly is going on in that cylinder. If you desire a more conclusive diagnostic, please request a misfiring diagnostic and the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.
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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.
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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.
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Check engine light rough then goes away code cylinder 2 misfire changed plugs wires and cylinder 2 coil driving me nuts
ANSWER : The only things left to check is compression and the condition of the injector if you have changed the plug, wire, and coil. I would go with having the injectors cleaned. It is more likely that you have a clogged injector versus an internal cylinder problem causing low compression.
Clean the injectors by using a professional cleaning machine. Afterwards, clear the codes and use fuel tank injector cleaner to help keep the injectors clean. If you need some assistance with this, contact a certified technician who will be able to diagnose your Check Engine Light firsthand and perform the necessary repairs to your car.
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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.
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Misfire code 302 cylinder 2
ANSWER : Hey there. Your logic is absolutely correct. This is in fact one of the most commonly used ways to diagnose a bad ignition coil. If the trouble code turns to a P0301, the ignition coil is faulty. If the trouble code remains a P0302, the problem could be the cylinder two fuel injector causing this issue. If this is the case, I would recommend enlisting the assistance of a qualified professional to replace your fuel injector on the number two cylinder.
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Experiencing rough idle and misfire on multiple cylinders on bank 2
ANSWER : Hello, thanks for reaching out to us about your Ford’s rough iding and misfiring. Typically, when your vehicle is running with these codes and symptoms, it’s due to faulty camshaft phasers that need replacing, or the timing chain is worn out.
Defective camshaft phasers are a common problem and will cause the variable valve timing to be off just enough to cause rough idling or misfiring. I would fix the camshaft phasers first, and if symptoms still occur, I’d recommend replacing the timing chain (you will need to remove the timing cover to do so).
If you’d like help with either of these tasks, consider YourMechanic and a certified mechanic can come to your home or office to diagnose and repair these issues for you.
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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.
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