I just noticed this problem today. My Alero will run fine while driving, but when I come to a stop for more than 2 or 3 seconds, it will begin to jerk back and forth, and the RPM's will jump between 500 and 750. When I take my foot off of the brakes, the problem still occurrs; it will slowly move forward while jerking around. I popped the hood to look at the engine while it was running, and I can see it psyically jostling around. When I accelerate from a stop, the problem seems to go away, but will come back again the next time I stop for more than a couple seconds. It shakes most violently in drive, neutral, and reverse,a nd is not as apparent when it is in park. It has 66,000 miles on it, 1999 Oldsmbile Alero GL with the 3.4l v6. Ive recently replaced the fuel filter, air filter, water pump, and pcv valve.

pps: It is currently mid-January, and I live in Southern maine, where temperatures are below freezing.... At first I thought it might have something to do with ice in my gas lines r something, but after driving it for several miles while fully warmed up, the problem persists. It just started happening one day...nothing leading up to it or anything. I'm not too sure what could be wrong with it, and I can't find too much info online either. If anybody knows what the source of my problem might be, please let me know.

Thanks for reading,
Jr. Gong

I wonder if your problem would be caused by motor mounts?

yeah, i got a service engine soon light yesterday, maybe a few hours after i made the post... so i dropped her off at a garage to get checked out...

i hope its something easy to fix like an O2 sensor or something, cause i dont have money for any expensive repairs.

when i find out whats wrong i'll post some details, so maybe it can help other people who have the same issue...

Did you find out what the problem was?

Let us know what the issue was. I had this on my 1997 Malibu 3.1L V6 and I could never figure out what it was.

Jeremy

good news.

as it turns out, it cost under $100 for parts, labor, and the diagnostic

my mechanic told me that it was a split line leading into the intake, so i guess that while idling, not enough air was getting to the engine.

I couldve saved myself a good $70 or so by running the free diag at autozone and replacing the line myself, but i needed it to get fixed right away... but oh well, what can ya do...

anyways, i was happy enough that it was a cheap easy fix....ive done a bit of driving since then, and it feels fine.

That is good news! Glad to hear that it didn't cost you an arm and a leg to get it fixed.