Carrier/rack problems of the 2006 GMC Envoy

The initial time (3/14) it occurred, I was out of town with my family, embarrassed to say the least. However, mainly uncomfortable, tired, and frustrated because my 87 years old dad was stranded for hours as well as my 66 years old sister who is recovering from cancer. This problem was a serious problem because of our location. We had gone to get dinner and ice cream after getting ice cream we back in the vehicle for it would not start. I called 911 no police ever showed nor would even stop to assist. After 2 1/2 hours, we contacted a church member to find out about a mechanic in the area that could possibly come check it out. Another church member came to check it first, by now 3 hours have lapsed and the vehicle starts. After this it has happened on three (3) separate occasions with me (3/19, 3/20, & 3/21) but my mechanic said it happened with him 3 or 4 times while he was driving it to check it out and while it was sitting just running not being driven. I was on the interstate once, once driving, and once parked and it would not start. The times I was by myself once was on the interstate, another was going through an intersection, and once was in a high crime area where I felt very unsafe for my vehicle and myself. My mechanic replaced the crankshaft and camshaft sensors and the problem persists. I had a diagnostic test performed but was told the items listed on the test �may� be the problem. I have also had a problem with it accelerating while driving as if the gas is not distributing properly. It was as if it was choking up as if there was a clog. A dangerous place to be in traffic or going across a railroad track, which it has occurred several times with me. I actually was almost rear ended on the interstate.

This problem is with the rear door 3rd brake light spoiler. Brackets holding it on broke. . Believe it to be a design fault after talking with junkyards and dealers about the problem. Junkyards tell me that is a big called for item, but it is dealer supplied only. Safety risk of it flying off and striking another vehicle.

I have had this issue 3 times -8/2012, 2/2013, 3/2014 - so I am on the 4th ignition switch in this car, mileage now approx 108,000. The 4x4, stabilitrak, abs and emerg brake lights come on then it beeps repeatedly. Sometimes concurrently, sometimes not the air blower stops working as well. This 3rd time, after the lights had been coming off/on for a few days, turning the blower on would trigger the lights to come on. For each of the 3 times, the GMC dealer has recommended replacement of the ignition switch (2x at my cost) on the most recent repair a voltage spike was acknowledged but the option to track this by installing inline fuses was not even offered until I had taken my issue to a higher authority. I declined as I don't care to put more money in a car that even one of the dealerships employees recommended I just sell and buy new. My concern is whether this car is a hazard to me and others? the service manager said when this occurs the ignition is essentially off and the car could stop but another person told me that no, it's another leg of the ignition and its okay. I don't know who to believe.