I have a Jeep Grand Cherokee Laredo with over 107,000 miles. A few weeks ago it revved up once when I shifted into drive. I thought maybe my foot had hit the gas pedal accidentally, so I thought nothing of it. About that same time it hesitated slightly when I yielded at a crossroad. So, last week, while driving on the interstate, it started slightly bumping forward. It repeatedly did this the entire way home and on the next day. Sometimes it would be fairly forceful, lurching or jerking forward, and acting like it was going to stall, but it doesn't. Of course, there are no warning or Check Engine lights, and it won't do it for the tech when it is in the shop. My guess is it's a transmission issue, but I can't check the transmission fluid because it is sealed.
The symptoms you describe on your Jeep Grand Cherokee lead me to believe that you may have a cam or crankshaft position sensor intermittently failing. If the computer does not know the location of the cam and crankshaft, then it is not able to tell the engine how to perform. This results in the symptoms that you have described with your Jeep. It is also possible for the cam and crankshaft position sensors to fail without displaying a Check Engine Light. To be 100% certain, it may be time to enlist the help of a certified mechanic to go over your vehicle with you. They will be able to perform an extensive test drive to duplicate your Jeeps concerns. They will take this information to assist in identifying exactly why your vehicle is hesitating and jerking. From there, they can assist in making the necessary repairs to get your Grand Cherokee operating smoothly again.
Have a car question? Get free advice from our top-rated mechanics.