I have a 2003 Cavalier with 77,000 miles and an auto trans. Sometimes when I start out I get a shudder for a second or two, then it goes ok. This usually occurs when stopped on a hill, but can happen on the flat as well. There are no codes being set either, which leads me to think it's not the trans, but not sure of that. I changed the fluid and filter, and everything looked good. It seems to run fine everywhere else, just pulling out. Appreciate any help you can offer.
My ecotec does the same, sometimes if shudders like it is going to stall when i am stopped at a light, it goes away after a second or two and runs fine for a long time. This used to happen frequently when the car was new, so it took it to the dealer and they did a pcm firmware upgrade. The upgrade did not fix the problem completely but now that car only does it 2-3 times a year instead of monthly like before.
Does it sound like the motor stumbling, or is it running fine when its shuddering?
Im right at 78K miles and I know my TC is going out, and its not throwing any codes. I haven't looked at the fluid yet, but Im sure its in need of change.
If you floor it and wait for a shift, does it promptly shift from 1-2 or does it hesitate, and wind up a bit more before it falls into 2nd?
Could be the Torque Converter if thats the case.
not 100% tho.. do you beat on the car at all?
I don't beat it around too bad. Sometimes it gets an erratic idle, then gets over it, a couple of times it stalled. I did some more experimentation, I didn't think that it was fuel, but I may be wrong. The car is dual fuel CNG/gasoline. I let it run out of CNG so it would switch to gasoline. I ran it from work to home and never had the shutter. However, this doesn't mean that something like a map sensor or misfire could not be the problem. I have experience when a misfire will show up in CNG and not gasoline yet, just because of the spark requirments for CNG. So, with that I am pretty sure that it is not the transmission anyway, which is a good thing. I'll let everyone know if I figure it out.
