Q: Bucking during acceleration.

asked by on October 08, 2016

Hello. I have two issues with my car. First issue is, while driving if I where to go over say 30 - 40 mph, the car would buck until I let go of the gas or accelerate out of the jumping then it would be fine, until I slow and start speeding up again. Sometimes the bucking would occur at higher speed as well. I don't have a check engine light on for this problem.

The second issue is my engine cooling fan and my auxiliary fan doesn't run on its own. I don't have any overheating issues with the car although, I can only use defrost/air condition while car is moving otherwise I would get what I think it's refrigerant shooting out the front of the car.

Any help on this would appreciated. Thank you for replying

My car has 111000 miles.
My car has an automatic transmission.

Hi there. It does sound like you have several different problems going on here. The bucking is usually the result of a failure in the throttle position sensor or the air flow meter. Both of these will commonly cause these same symptoms on this vehicle. I usually check these with a scan tool to make sure they are fine. It can also be a transmission problem, but that is not too common on this car. As for the fan, most of the time this is a failure in the fan assembly itself. The fans fail and will no longer turn on. It can also be a problem with the circuit so I usually test the motor for the fan first and then diagnose the circuit if the fan is fine. If you want to have this bucking and this cooling fan problem checked, consider YourMechanic, as a certified mechanic can come to your home or office to diagnose and repair this.

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