I have an automatic transmission 2000 Olds Alero (V6 engine) and for the past couple of years, whenever I take a long trip (longer than 3 hours), or the car has been sitting in the hot sun for a while (I live in the south), the shift from 1st to 2nd gear is more like an abrupt jolt than a smooth shift. Since I don’t take many long trips, this is rarely an issue, and it shifts fine around town and on shorter trips. I thought it might have something to do with the fluid getting hot? I am taking a long trip in the next few days and am wondering if I should be concerned?
Have you had the AT serviced, filter and oil? It might have more to do with a driving pattern, harder accel vs just puttering around town. If you are due then get the AT serviced. It could also be a vaccum leak but that depends on your driving style.
When was the last time the transmission fluid was serviced?
I had it serviced in Aug. of 2007 after a cross country trip where I was hauling a trailer (and we babied the engine the whole way!), and it was after this trip/service that it first started doing this on long trips. I’ve put about 20,000 miles on it since then. My mechanic wants to do a fluid changeout, but my manual tells me it should NEVER have to be serviced, because, obviously, GM products are supposed to be so good. (I have a right to be sarcastic, I have had the intake manifold gasket replaced twice because of their Dexcool antifreeze). Anyway, if servicing it again would help. . .my mechanic did say that the fluid looked dirty, but it only being 2 years from the last service, I don’t know what to believe.
The harsh shift MAY be from a worn or dirty pressure control valve in the tranny.
You can try a tranny fluid drain and filer/screen replacement. NOT A FLUSH!
I had this problem with a 2000 Silhouette I had and it worked.
Tranny fluid should be changed every 30-40k miles, less when towing a trailer.
I used to have mine serviced at 25k miles.
What is the mileage on your Alero?
It has a little over 85,000 miles on it.
Ok, I just read another post (Not here) where the OP had similar problems and it turned out to be a faulty MAF sensor. It’s worth a look.
I would start by having the computer scanned for current and history codes. This could be just something that the computer is doing because it is finding a problem.