She failed to mention that she just blew a head gasket resulting in a valve job, complaining that they did an oil chance without authorization, So either she pissed them off and they put worn plugs back in it or they were like new. Kinda like the head bolts they didn't replace.
As someone who taught drivability you guys are speaking "alien" to her. The complete loss of power and correcting it's self by doing a wiggle test means that the wiring harness may have been damaged or has a loose connection due to breakage when serviced.
The 2 things that can cause this is the wiring controlling the coil packs either loose or damaged when they did the valve job or the fly by wire throttle body (TBA) actuator was left loose or it has bit the dust (see pic) as GM has had lots of issues with these and most shops replace the TB to cure it.
Codes for misfire or TBA would be helpful. Wouldn't be the first time a shop fixed something and either broke something or left it loose.
Get all codes in system written down, verify that the wiring and connectors look good(unplug and reconnect), CLEAN THE THROTTLE BODY WITH PROPER CLEANER AND TOWEL, clear the codes, and take it for a ride.
there are 2 actuators one on gas petal and one on TBA. TBA unit is about $250 for GM part, $175 for aftermarket or Amazon has a deal, http://www.amazon.com/ACDelco-217-31.../dp/B001C6JUE8
Originally Posted by Cooper Barrett
+1
Also of note if under your drivers seat has ever had water there -as in left the window down and it rained etc etc there are connections that are sometimes the cause of what you say your vehicle seemed to be doing .
But i agree 100 % with the Gent above about sticky and gummed up .
How many miles are on it ?
If you sweet talk your GM service manager i have heard of these being taken care of!
My 2011 tahoe in 2014 had 44,000 on it and did same thing.
I searched and searched till i found a women service manager at a gm dealership and i took her to lunch and hubba hubba truck was out of warranty at 36000.
I lied about the last part and the warranty is 56 000 on that part i do believe .
But listen to the guy i quoted he obviously knows his shit cuz thats exactly what it will be .
One thing for sure to never use is On Star and there BS diagnostic reports .
In Gm cars since 1997
Just think they should of called your cell the minute it happened and told you the codes exactly and already had a tow hook on the way !!!