Car stops, then 'jumps'


#1

I have a 2003 grand prix. Sometimes when i am completely stopped at a light, then put my foot on the accelerator as it turns green, the engine will start accelerating but the car wont move for a second. It then jumps forward in a frightening way. It feels like the brakes dont completely disengage or maybe a belt is slipping. I also notice when im driving and take my foot off the gas for a second and putit back on the RPMs will jumpup about 1000. Im not an agressive driver or anything at all. Anybody have ideas?


#2

This sounds like a transmission problem, unfortunately. Is your transmission fluid at the right level? Is it red without a burnt smell? Has the transmission been maintained according to the instructions in the owner’s manual?


#3

Do you regularly use the parking brake? How old are the brakes? When was the last time someone looked at them?


#4

The transmission fluid is at the right level, but I do notice a strong burnt oil smell when im driving and after I turn the car off. I do not know what has been maintained, there is no owners manual either. I just bought this car about a month ago from a dealer in town.

I have never used the parking break; I don’t know how old they are either. I assume they must be fairly new since I bought this from a dealer, but I see now that I really should get it in to my mechanic.


#5

recrux wrote:
I do not know what has been maintained, there is no owners manual either. I just bought this car about a month ago from a dealer in town.

Let’s hope for the best, but there’s a decent chance you bought a car that someone dumped because of serious problems. I’m guessing you didn’t have a mechanic inspect the car before the purchase, right?


#6

No nobody inspected it before purchase. The man I bought it from is a mechanic himself; he buys cars with no serious issues that are easy & cheap to repair, then resells them to others. He’s got a good reputation in my town too. I knew when I bought it that it would need tires soon, and it was fantastic during the test drive. I guess next time I really should have someone inspect it for a second opinion. Live and learn…


#7

If the guy has a good reputation then maybe it had a problem that he didn’t know about. Perhaps since he is a mechanic it would be worth the trouble to stop by, explain the symptoms, and ask him for advice. Perhaps he’d be willing to help out in some way.

It does sound like a transmission issue - called “neutraling”


#8

Thank you everybody for your input!

cigroller what exactly is neutraling? is it when the car is not fully in drive?


#9

This is a simplistic, amateur version - partly to keep it simple but mostly b/c its all I got - what is going on inside of an automatic transmission works by fluid pressure. Transmission fluid basically mushes friction disks (clutches) together to put a car in gear. The fluid has to run through lots of little passages & stuff & there are all of these points where those have to seal up or they won’t keep the pressure.

When you sit at idle, the transmission doesn’t have anything to do so the fluid pressure gets low. But it should stay high enough to keep 1st gear engaged. You probably have a leaking internal seal that drops the pressure to the point that it basically drops out of 1st gear. When you step on the gas, mechanically speaking the transmission is in neutral regardless of what your gear shifter says. But stepping on the gas ups the transmission line pressure, activates the clutches again & bam, you’re off & running.

But make sure you keep the following in mind: first, that is the simplistic amateur’s version, and second we’re only making guesses about your problem to begin with. If I were you I would run it through your best local transmission shop to have them drive it & check it over.