# Jumping car **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** chevrolet, beretta\ **Created:** [September 18, 2010, 1:12am UTC](https://community.cartalk.com/t/jumping-car/55261 "2010-09-18T01:12:45Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![Beretta\_94](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/beretta_94/32/2010_2.png) [@Beretta\_94](https://community.cartalk.com/u/Beretta_94)\ **Post date:** [September 18, 2010, 1:12am UTC](https://community.cartalk.com/t/jumping-car/55261/1 "2010-09-18T01:12:45Z")
when I let off the gas, sometimes (almost always) the car starts to jump. If I press the gas or the brakes, it stops jumping. What is the cause of this? This is on a 94 Beretta with a 2.2L manual tranny ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [September 18, 2010, 1:25am UTC](https://community.cartalk.com/t/jumping-car/55261/2 "2010-09-18T01:25:54Z")
When was the last time the front suspension was inspected? Because from what you describe it may be a lower ball joint that’s ready to fail. And if that happens, you’re in for the ride of your life! Have the front suspension inspected. I had a 1995 Beretta. Tester ---
**Author:** ![Beretta\_94](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/beretta_94/32/2010_2.png) [@Beretta\_94](https://community.cartalk.com/u/Beretta_94)\ **Post date:** [September 18, 2010, 1:33am UTC](https://community.cartalk.com/t/jumping-car/55261/3 "2010-09-18T01:33:08Z")
I don’t know when the last time was. If I can keep an even speed it runs just fine. Is it possible to replace the ball joint without taking it to a shop? ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [September 18, 2010, 1:48am UTC](https://community.cartalk.com/t/jumping-car/55261/4 "2010-09-18T01:48:35Z")
You first have to know how to inspect the front suspension before learning how to replace a ball joint. So no. Tester ---
**Author:** ![Beretta\_94](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/beretta_94/32/2010_2.png) [@Beretta\_94](https://community.cartalk.com/u/Beretta_94)\ **Post date:** [September 18, 2010, 2:25am UTC](https://community.cartalk.com/t/jumping-car/55261/5 "2010-09-18T02:25:25Z")
what happens when the lower ball joint fails if Im on the road when it does go? ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [September 18, 2010, 2:34am UTC](https://community.cartalk.com/t/jumping-car/55261/6 "2010-09-18T02:34:15Z")
The tire will fold either under the vehicle or outside the vehicle, and you’ll have no steering. Tester ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [September 18, 2010, 3:13am UTC](https://community.cartalk.com/t/jumping-car/55261/7 "2010-09-18T03:13:43Z")
Here’s an example of a lower ball joint failure. [http://www.aa1car.com/library/wheel\_missing.jpg](http://www.aa1car.com/library/wheel_missing.jpg) Tester ---
**Author:** ![Caddyman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/caddyman/32/23_2.png) [@Caddyman](https://community.cartalk.com/u/Caddyman)\ **Post date:** [September 18, 2010, 3:33am UTC](https://community.cartalk.com/t/jumping-car/55261/8 "2010-09-18T03:33:14Z")
" the car starts to jump. " Perhaps you could elaborate a little more on that…I’ve never seen a car “jump”, except some Mexican creations with hydraulics in them… ---
**Author:** ![Beretta\_94](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/beretta_94/32/2010_2.png) [@Beretta\_94](https://community.cartalk.com/u/Beretta_94)\ **Post date:** [September 18, 2010, 3:42am UTC](https://community.cartalk.com/t/jumping-car/55261/9 "2010-09-18T03:42:53Z")
the car starts jerking forward (like when a person forgets to shift into neutral when they stop). When it starts jerking, I can either press the brake, gas, or do nothing and it will eventually stop jerking. ---
**Author:** ![Beretta\_94](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/beretta_94/32/2010_2.png) [@Beretta\_94](https://community.cartalk.com/u/Beretta_94)\ **Post date:** [September 18, 2010, 3:43am UTC](https://community.cartalk.com/t/jumping-car/55261/10 "2010-09-18T03:43:26Z")
I have never seen anything like that. ---
**Author:** ![Caddyman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/caddyman/32/23_2.png) [@Caddyman](https://community.cartalk.com/u/Caddyman)\ **Post date:** [September 18, 2010, 3:49am UTC](https://community.cartalk.com/t/jumping-car/55261/11 "2010-09-18T03:49:18Z")
Clean the MAF, check the operation of the EGR valve, check for a vacuum leak and the throttle position sensor… ---
**Author:** ![Beretta\_94](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/beretta_94/32/2010_2.png) [@Beretta\_94](https://community.cartalk.com/u/Beretta_94)\ **Post date:** [September 18, 2010, 3:52am UTC](https://community.cartalk.com/t/jumping-car/55261/12 "2010-09-18T03:52:41Z")
where would I find the EGR valve and the throttle position sensor? ---
**Author:** ![Caddyman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/caddyman/32/23_2.png) [@Caddyman](https://community.cartalk.com/u/Caddyman)\ **Post date:** [September 18, 2010, 3:57am UTC](https://community.cartalk.com/t/jumping-car/55261/13 "2010-09-18T03:57:13Z")
Time to by a service manual for your car… ---
**Author:** ![Beretta\_94](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/beretta_94/32/2010_2.png) [@Beretta\_94](https://community.cartalk.com/u/Beretta_94)\ **Post date:** [September 18, 2010, 4:12am UTC](https://community.cartalk.com/t/jumping-car/55261/14 "2010-09-18T04:12:31Z")
Lol. Thank you. Could it also be the lower ball joint as well? My original thought was that it had something to do with the throttle body itself. ---
**Author:** ![Beretta\_94](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/beretta_94/32/2010_2.png) [@Beretta\_94](https://community.cartalk.com/u/Beretta_94)\ **Post date:** [September 18, 2010, 5:49am UTC](https://community.cartalk.com/t/jumping-car/55261/15 "2010-09-18T05:49:07Z")
how can u tell if the throttle position sensor is bad