{"id":677,"date":"2024-02-11T16:01:35","date_gmt":"2024-02-11T16:01:35","guid":{"rendered":"https:\/\/jeepadvices.com\/how-to-troubleshoot-the-jeep-grand-cherokee-3-7-misfire-problem\/"},"modified":"2024-02-15T08:25:34","modified_gmt":"2024-02-15T08:25:34","slug":"how-to-troubleshoot-the-jeep-grand-cherokee-3-7-misfire-problem","status":"publish","type":"post","link":"https:\/\/jeepadvices.com\/how-to-troubleshoot-the-jeep-grand-cherokee-3-7-misfire-problem\/","title":{"rendered":"How to Troubleshoot the Jeep Grand Cherokee 3.7 Misfire Problem?"},"content":{"rendered":"\n
Engine misfires are one of several typical issues that 3.7 engine owners of Jeep Grand Cherokees encounter. And this typically occurs when there is incomplete combustion in one or more cylinders. <\/p>\n\n\n\n
Keeping the issue unfixed for a long time can lead to costly repairs like engine failure. But no worries, we will help you figure out how to troubleshoot the Jeep Grand Cherokee 3.7 misfire problem.<\/p>\n\n\n\n
Your Jeep Grand Cherokee’s 3.7-liter engine may exhibit a number of symptoms that indicate misfiring. <\/p>\n\n\n\n
Among them, the reduction in engine power is the most prominent. Some of the other symptoms are; <\/p>\n\n\n\n
You will find many essential components related to the engine chamber of your Jeep Grand Cherokee 3.7 engine. <\/p>\n\n\n\n
And it makes sense that even if single components malfunction, like the spark plugs, there will be an imbalance in combustion, which causes the engine to misfire. <\/p>\n\n\n\n
The spark plugs are critical internal combustion engine<\/a> components as they ignite the air-fuel mixture.\u00a0<\/p>\n\n\n\n However, if the spark plugs in any cylinder go bad, it can most often cause interrupted combustion in the engine cylinder. <\/p>\n\n\n\n And due to incomplete combustion, the internal combustion engine is supposed to misfire as there is an imbalance in the air-fuel-mixture. <\/p>\n\n\n\n There is a close connection between the spark plugs and ignition coils, which is why issues with the spark plugs can also affect them. <\/p>\n\n\n\n The ignition coils play their part in transferring battery voltage to ignite the air-fuel mixture from the battery. <\/p>\n\n\n\n And so, if the ignition coils go bad or are damaged, there won\u2019t be enough battery power for spark plugs to ignite the air-fuel mixture. <\/p>\n\n\n\n Due to this, there will be a lack of combustion, and the engine is supposed to misfire. <\/p>\n\n\n\n The core duty of a vacuum hose is to deliver air into the engine cylinder of your Jeep Cherokee 3.7. <\/p>\n\n\n\n But unfortunately, if the vacuum hose becomes damaged or broken, it can cause additional air to enter the engine cylinder. <\/p>\n\n\n\n And when there is too much air in the engine cylinder compared to fuel, it creates an inappropriate air-fuel ratio, leading to incomplete combustion. <\/p>\n\n\n\n The cylinders of your Jeep are not supposed to ignite the air-fuel mixture as expected. <\/p>\n\n\n\n The O2 sensor on your Jeep Grand Cherokee signals the amount of air in the exhaust to the PCM. <\/p>\n\n\n\n And then, your Jeep’s control unit determines the air-fuel mixture needed for improved combustion.<\/p>\n\n\n\n Sometimes, the 02 sensor of your Jeep becomes faulty, which can lead to an inappropriate signal received by the PCM about the amount of air. <\/p>\n\n\n\n And thus, chances are there is too much air-fuel-mixture that can be too lean or rich, which can cause inappropriate combustion. <\/p>\n\n\n\n The exhaust manifold of your Jeep Grand Cherokee transfers the exhaust gas to the exhaust system. <\/p>\n\n\n\n However, if there is leakage in the exhaust manifold, it can drive too much air into the engine intake system. <\/p>\n\n\n\n And ultimately, this can cause a lean air-fuel-mixture, meaning there will be more air than fuel in the engine combustion chamber, which can cause incomplete combustion. <\/p>\n\n\n\n The main job of the fuel injector in your Jeep Grand Cherokee 3.7 is to deliver fuel to the engine combustion chamber from the fuel line. <\/p>\n\n\n\n But, when the fuel injector becomes clogged or dirty, the right amount of fuel can’t reach the engine chamber for proper ignition of the air-fuel-mixture. <\/p>\n\n\n\n Or, it causes a lean air-fuel-mixture, which ultimately causes engine misfire due to imbalanced combustion.<\/p>\n\n\n\n A Mass Airflow Sensor (MAF) ‘s role differs from the O2 sensor on your Jeep Grand Cherokee 3.7. <\/p>\n\n\n\n The MAF sensor monitors the air entering the engine cylinder and sends this information to the control unit of your Jeep. <\/p>\n\n\n\n But when the MAF sensor becomes faulty, it cannot send proper information about the air entering the engine chamber to the control unit. <\/p>\n\n\n\n And thus, there will be an improper air-fuel-mixture on the engine cylinder. The air-fuel mixture can be too rich or lean, which can cause the engine to misfire. <\/p>\n\n\n\n There are many causes behind the low fuel pressure in the engine. The fuel pump may go, or something is wrong with the filter. In addition, chances are there is an issue with the fuel line. <\/p>\n\n\n\n And when there is low fuel pressure due to a lack of fuel in the engine chamber, the air-fuel mixture can be too lean. <\/p>\n\n\n\n Due to excessive air and fuel in the engine chamber, incomplete combustion can occur, causing the engine to misfire. <\/p>\n\n\n\n Now you know the possible causes of engine misfires on your Jeep Grand Cherokee 3.7. In this part of the blog, you will see the solution to getting rid of the issue. <\/p>\n\n\n\n You\u2019ll probably notice the spark plugs in worn-out condition. In addition, spark plugs full of dirt, oil, and debris and covered with corrosion can be a common scenario. <\/p>\n\n\n\n So, you should clean the spark plugs first. If cleaning doesn\u2019t work, you need to replace it<\/a>, which will cost you around $120-$380, including parts and labor costs.<\/p>\n\n\n\n First, you should check the ignition coils carefully to see if there is any corrosion. Next, you have to clean the corrosion, if there is any. <\/p>\n\n\n\n If cleaning the corroded ignition coils doesn’t work, you have to go for a replacement, which can cost you $180-$250. <\/p>\n\n\n\n Here you can check this video to replace the ignition coils of your Jeep Grand Cherokee 3.7.<\/p>\n\n\n\nBad Ignition Coils<\/h3>\n\n\n\n
Broken or Bad Vacuum Hose<\/h3>\n\n\n\n
Faulty O2 Sensor<\/h3>\n\n\n\n
Exhaust Manifold Leak<\/h3>\n\n\n\n
Faulty Fuel Injector<\/h3>\n\n\n\n
Faulty MAF Sensor<\/h3>\n\n\n\n
Low Fuel Pressure<\/h3>\n\n\n\n
How to Troubleshoot Jeep Grand Cherokee 3.7 Misfire Problem?<\/h2>\n\n\n\n
Check and Replace the Bad Spark Plugs<\/h3>\n\n\n\n
Check and Repair\/ Replace the Bad Ignition Coil<\/h3>\n\n\n\n