My sons 03 Impala was jerking very bad and check engine light came on. Based on the codes the solenoids were replaced and new fluids put in. However a few days later it started lightly jerking again and you can feel a hard shift into the next gear when accelerating, but the check engine light has not come on. Any ideas on what would cause this issue?
What solenoids were replaced. Starter?
What codes did you get.
New fluids would not have any effect on a car jerking.
Spark plugs, dirty air filter, contaminated fuel, poor fuel pressure, all could.
Yosemite
I’m presuming some transmission solenoids were replaced. But that hasn’t done the job. If the shop has isolated this to the transmission (and presuming an automatic), probably start with a proper transmission service. If it helps but doesn’t fix it 100%, drive 100 miles and do it again. Still got a problem? You need a transmission expert at that point. They’ll probably measure the transmission fluid pressure at several test ports.