"Jolting" at 45-55 MPH; 2009 Aveo Hatchback

[navvet1]

Check one of two possibilities (of which I had both on my 2010 LT): Look for a tear or split in the air intake tube (between the mass air flow meter and EFI intake port). Mine was torn, took me a while to figure it out, had no desire to cough up $240 for a new one so I fabricated one from an aftermarket Koni-type intake filter and hose assembly (about $20, got that back selling the filter to a friend of my son). That issue went away. If the problem turns out to be the coil pack, don't get the original from the dealer, there is a problem with the design that will always give a misfire on cylinder 3 code. I went for a Duralast coil pack from Auto Zone, no more misfire code. Hope this helps.

[PoisonIvy]

If you have a check engine light and a blinking hold light, the Aveo will no longer go into overdrive. That's most likely why he's seeing such high rpm.