What would make a thumping noise on right front side of Chevy cavalier?

Answer 1

My upper motor mount was bad and it was the cause of the thump. It happened when I let off the accelerator, turned a corner and accelerated, or just any time the rpm's changed. Open the hood, have someone start the motor while you watch the upper motor mount. If the motor jumps a lot and clunks it's probably the motor mount. Replace it yourself for about $60 to $100. Let GM replace it for about $350. Its a 1 hour job for you or them. Hope this helps. If the thump occurs on bumpy roads it could be a bad strut. A simple way to check this is to rock the right front of the car up and down by pressing your weight down on the hood near the wheel well until you have a good rhythm going, then let go and if the car car continues to rock up and down more than once or twice then the strut is worn. To more accurately check the motor mount watch it while someone holds the brake while shifting between reverse and drive while the motor is running, listen especially for the familiar thumping sound coupled with your observation. If the sound is occurring when driving, especially while turning or cornering, then the most likely cause is the C.V. axle. They are relatively easy to change, but it would be more like a loud clicking sound in this case. The price is usually around $100 dollars for a new one verses 20 - 35 for a used one. I would recommend a new one if you expect to drive your car for some time yet. You can buy a step by step repair manual for around $16 that would cover all of the above repair procedures.