Vibrating engine?

mycarhatesme1

Ok, so I'm no car genius, but something is definitely wrong. I own a 1999 Pontiac Grand Am and something is always going wrong with it. This particular time, I was leaving a doctors visit and when I put it into drive, the car began to vibrate (well, more like shake violently) when I slowly applied pressure to the gas pedal. The vibration seemed to fade away as my speed increased, but when stopping at the next light, I found that the problem started again. I pulled into a parking lot and shut it off, sat for a moment, then restarted. The car was fine in park, but the moment I shifted into gear it started back up again. I checked the oil (seeing how it had been a while) but found that I was still just beneath the full line. I continued on my way home and found that the problem subsided altogether about three miles from my house. What in the world is going on?

(side note: The car has also had a little trouble starting lately... It does start every time, but sometimes requires a longer turn of the ignition.)

burdawg

If you leave it in park and just apply throttle, what does it do? Sounds like it wasn't firing on all cylinders, or the engine was starved for fuel. Just guesses though. Also, 4 or 6 cyl?

dulinaa

Sounds like you have a misfire on one or more cylinders. Have your replaced the spark plugs recently? I have had cars that seem to idle ok, hiding a misfiring cylinder, until you apply some gas.

random_guy

i dont know a whole lot about cars, i do however have many mechanics in my family and have learned enough to diagnose most of whats wrong with my vehicles. my 2000 mitsubishi eclipse has the same prob., has for quite a while and i know there is nothing majorly wrong w/ it. i have talked to my family and the prob. is most likely a motor mount. My car is too old and close to expiring for me to care. i thought this could be helpful to you though. i hope this helps!!!

larry4250

could very well be one of the motor mounts. had a car that did the exact same thing, unless it was warm outside.then it would only rattle when i hit a bump in the road,so i replaced the worn out mount and fixed the problem....surely you have it fixed by now according to the date of your post, but just in case...

mechanic of 20+ years

ryanl1991

are you getting a P0300 engine random misfire and when you start when cold it doesn't vibrate and when it reach mid temp it runs like its going to die. because mine is doing it to I found out that fuel injectors where bad I replace all of them but you don't have to replace all of them just that its better to replace all of them to clear the problem. at first I was thinking it was a ignition problem but it wasn't so don't replace ignition parts tell you test the fuel injectors. also check the map sensor vacuum line they tend to crack and cause your engine to run rich.