If your engine is skipping, popping, or going silent in between rotations, it’s called a misfire.
This happens when something goes wrong with the internal combustion system.
Unfortunately, causes can be diverse and fixing the issue can range in cost depending on whether you’re fixing a vacuum leak, a spark plug issue, or a faulty catalytic converter. So, the actual cost of repairing a misfiring engine can vary dramatically.
However, on average, you can expect the cost of repairing a misfiring engine cylinder to range between $150 and $1,000. If your catalytic converter is out, that could go up to over $3,000, and if it’s a seal, as low as $50. However, you can normally expect roughly $500 including parts and labor.
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Engine Cylinder Misfire Repair Cost Breakdown*
Every engine has 4, 6, or 8 cylinders, which rotate in response to the force of the fuel combustion in the engine. When one misfires, it normally means that something is off with the fuel injection system, including the vacuum system, fuel injection, exhaust, and ignition system.
This means that costs to repair an engine cylinder misfire can vary significantly depending on which part of your system is having issues. In fact, you’ll almost always have to start out with a diagnostic assessment to see what’s going wrong. And, that usually costs about $95 – although many mechanics will apply that cost as a discount to your final bill if you do the work with them as well.
|Cause of Misfire||Part Cost||Labor Cost|
*Please note: these cost estimates are based on market rates at the time of writing in December 2022. Pricing is subject to change at any time. In addition, costs will vary significantly depending on your vehicle.
Here, it’s extremely important to note that your vehicle will significantly impact the cost of labor and parts. For example, if you narrow your engine cylinder misfire down to a single issue like a bad fuel injector, you can still see significant variations in cost based on your vehicle.
|Vehicle||Fuel Injector Cost||Cost of Labor|
|Ford F Series||$32.99-$65||$400-$550|
|Dodge Ram 1500||$88-$499||$450-$700|
So, your total costs will depend on which vehicle you’re driving and where you go to have the repair done.
Engine Misfire Repair Pricing Factors
Fixing an engine misfire might be as simple as tuning the valves in your vacuum system. However, it might be an expensive part replacement. Understanding how different factors impact the total cost of your repair will help you to better understand your quote.
Cause of the Misfire
Repairing your engine misfire will vary in cost depending on what the cause is. Here, you might be able to get away with half an hour of your technician’s time and repairing a vacuum seal. On the other hand, you might have to remove the catalytic converter and replace it.
The fuel injection system interacts with many other parts of the vehicle, which will mean diagnosing the issue and inspecting the vehicle. Here, the fuel injection and spark plugs or ignition coil are very common causes. However, even a defective vacuum boost on your brake can cause the engine to misfire. And, your issue could be caused by something as simple as a blocked engine exhaust.
Cost of Labor
Most mechanics in the U.S. charge between $15 and $210 per hour. That works out to about $45 as a “standard fee”, about $95 for chain shops, $145 for most dealers, and $200-$210 in very densely populated urban areas.
In addition, repairing a vacuum leak can take anywhere from 1-8 hours depending on the issue. On average, you can probably find and fix the issue in about 3 hours. This means you’ll normally expect to pay around $200-$600 in labor costs alone.
Vehicle Make and Model
The make and model of your vehicle will significantly impact the cost of repair. Here, factors include the onboard diagnostics system and if your mechanic or technician has the software for it. You’ll also have to factor in the mechanic’s familiarity with your vehicle. If you have a more common vehicle, they’ll likely have a better idea of what’s going on and why, because they’ve seen the issue before. That can speed up the repair.
Finally, vehicle make and model will always impact the cost of parts. Even if you’re buying aftermarket parts, some vehicles just have more expensive parts. If you buy Original Equipment Manufacturer parts, you can also expect to pay a lot more for those parts. So, brand matters. In addition, if you’re working with a mechanic, you’ll have to discuss with them what kind of parts they will install, why, and what they recommend.
Replacement Parts Needed
An engine misfire can be caused by a valve left open. It might also be caused by your valve cylinder seal – which can cost up to $350. Or, you might have to replace the catalytic converter, which can cost over $1,000 in parts. Therefore, the actual problem will significantly impact what you spend before labor. Here, the only way to get a quote is to narrow down the cause of the misfire.
4 Causes of Engine Misfire
There are many reasons your engine could misfire. However, the following 4 reasons include some of the most common.
1. Vacuum Leak
Vehicles use vacuum pressure to assist braking, assist fuel injection, and mix air and fuel for injection into the combustion chamber. When a leak happens in any of those systems, it can throw the fuel air mixture off. If there’s too much fuel, the ignition might not happen. Or, the combustion might be too strong, causing the cylinder to skip. In either case, your engine will misfire.
Fixing vacuum leaks will depend on where the leak is located. Here, you’ll have to inspect the brakes, fuel injection, vales, seals, and lines along the system. Even the head gasket could be causing an issue. Plus, your exhaust can actually cause a vacuum issue as well.
2. Emissions Issues
Your EGR system impacts the vacuum and fuel injection system. The Exhaust Gas Recirculation system or EGR is made up of sensors, valves, and lines intended to recirculated engine exhaust so that it is re-combusted and filtered – reducing the amount of harmful gasses released into the environment.
However, this system works by taking engine exhaust and moving it back into the fuel injection. If there’s a leak, the valve is not letting off enough pressure, or is letting off too much, you’ll get issues that are very similar to a vacuum leak.
However, emissions issues can also relate to problems at any point in the exhaust system. For example, if your catalytic converter is damaged or clogged. Or, if you have too much carbon buildup in the exhaust chamber. If your exhaust is damaged or torn, it might also cause engine misfires by changing the air pressure in the engine. So, it’s always a good idea to inspect the exhaust as part of identifying why your engine is misfiring.
3. Ignition Issues
When your engine turns over, the ignition coil pulls power from the battery and transforms it to a high voltage, which is transferred to the spark plugs. These plugs ignite the fuel as it’s injected into the engine for that cylinder.
If something goes wrong with the power supply or the part at any of these steps, your engine may not fire on that rotation. Here, issues can be with the battery, the wiring, the ignition coil, or the spark plugs. In addition, spark plug issues may be caused by gasket issues, which will mean replacing the valve cover gasket.
Here, you can do a simple check of pulling the spark plugs out. If they’re covered with oil, the gasket is bad and that’s likely the cause of your issue. If your lights are flickering or your headlights are dim, the issue is likely with the battery. However, narrowing this issue down normally requires a diagnostics check.
4. Fuel Injection
Issues with the fuel injection system always cause engine misfires. This includes fuel pressure, fuel filters, lines, and fuel injectors. If you have clogs, damaged filters, or faulty sensors, it could cause the fuel injection timing to go off. That could result in the fuel injecting fuel too late, missing the cylinder, and causing a misfire. In most cases, an engine diagnostic will tell you what’s wrong if it is a fuel injection issue.
4 Symptoms of Engine Cylinder Misfiring
If your engine is misfiring, you’ll notice that it’s actually physically misfiring. However, there are other symptoms that will show you have an engine problem. However, engine misfiring is a symptom of another problem. This means that if you’re looking for symptoms of engine misfiring, you’ll always be looking for symptoms of those problems.
1. Strange Engine Sound
If your engine sound changes, it normally means that something is wrong. Here, you want to listen for coughing, sputtering, and interrupted engine rotation. However, if your engine ever changes the sound it makes, it’s a good reason to either take the vehicle in for an inspection or to inspect it yourself.
2. Reduced Acceleration
If you’re losing power, it’s almost always a sign that something is going wrong with the fuel injection, exhaust, vacuum system, or transmission. All of those issues are serious and can result in further damage to your vehicle if you keep driving with them. So, if you notice sluggish acceleration or reduced power, inspect your vehicle or take it in for a diagnostic check.
3. Exhaust Smoke
If you’re seeing exhaust smoke, it’s usually a sign that your engine is misfiring or you have issues that could cause it to do so. Here, exhaust smoke may actually be illegal, so it’s important to have your vehicle checked as quickly as possible. Exhaust smoke is always a sign of an issue, although it can be any of the issues mentioned for engine misfiring.
4. Rough Idle
If your vehicle is idling rough, it normally means there are issues with the fuel injection, power, vacuum system, or the exhaust. Any of these can cause a rough idle and an engine misfire. However, even if a rough idle isn’t accompanied by an engine misfire, it’s important to get your engine checked, because rough idling is always an issue.
Will Driving With A Misfire Damage My Engine?
If your engine is misfiring it means that your fuel injection system is going wrong. That can cause extra stress on every part of the engine. And, the longer you leave it alone, the worse that problem can get. For example, if you have a vacuum leak issue, the problem could eventually warp parts of the engine, making it impossible to fix.
Eventually, the sooner you repair an engine problem, the less likely it is to cause more damage or damage that you can’t repair. However, it is normally “safe” to drive your vehicle for short periods as it’s unlikely to immediately throw out a cylinder.
4 Steps Repairing Process
Repairing a misfiring cylinder will significantly depend on what’s gone wrong and why. Therefore, the first step to fixing the issue will always be to figure out what’s going wrong.
- Inspect the vehicle for obvious issues or signs of damage. Checking the spark plugs for oil residue, the exhaust for physical damage, or the battery for power are a good place to start. If you find obvious issues, you can skip the next step.
- Run an engine diagnostic. Do so at a mechanic or use your own diagnostic tool. Then check the codes to see what’s gone wrong.
- Decide to do the work yourself or have a technician do it for you. Some car repairs, like replacing the spark plugs, are very easy to do at home. On the other hand, cleaning the combustion chamber to remove carbon buildup would be time-consuming and difficult to do yourself.
- If you’re doing the work yourself, research and check which parts and tools you need for the job and complete the repair.
However, with dozens of issues that could cause an engine misfire, the inspection and diagnostics may take a considerable amount of time if your onboard software doesn’t pinpoint the issue.
Engines misfire when there are issues with the vacuum pressure, fuel pressure, fuel injection, exhaust, emissions, fuel ignition, or some other issues. This means that an engine misfire is a symptom of another issue. Fixing it will always mean finding the issue and then fixing that cause. This means that repair costs can range between $50 and $3,000+, but you can expect an average of about $500 for most issues.
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