Bizarre engine shutoff only while turning left

[400K_or_bust]

For about the past 6-8 months my 02 Yukon has intermittently and randomly lost all power multiple times and also used to randomly die at idle when first starting for the day.

I've had the truck worked on multiple times over that span. This is what I have had replaced during each trip to shop (some visits were for oil leak but including in case it's relevant)

1st trip--- Rear main seal May, 2017
2nd trip -- oil sending unit May 2017

3rd trip---Knock sensors, spark plugs, spark plug wires, fuel filter, knock sensor harness, camshaft sensor, crankshaft sensor, manifold absolute pressure sensor, manifold gasket, valve cover gasket, valley gasket--September 2017

2nd trip (revisited)--- I made the mechanic from 2nd trip redo main seal due to continued leaks October 2017

4th trip--throttle body service, carbon flush, PCV system service, left upper ball joint. December 2017


So up until the 1st trip the truck was randomly dying at idle when first starting. Not very often, probably 15-20% of the time. Only when cold...and was also leaking oil like a sieve...

After the 3rd trip the truck quit leaking as MUCH oil (but was still slightly leaking), but it still did not feel like I was getting full power to it at times. However, since then the rig has completely died multiple times (less than 10 but more than 4..dont quite remember) ONLY WHEN TURNING LEFT. Every time I was able to coast to a safe place in neutral, place the vehicle in park and refire the engine with no issues whatsoever. It always occurred within 10 minutes of starting for the day though. So the left turn and within 10 minutes are the only two predictable things about it.

The 4th trip was 9 days ago and since then the truck runs fantastic!! I can feel more power and more response, acceleration is smoother and generally everything is gravy. I was relaxing thinking that my issues with dying were finally over UNTIL whilst turning left into a parking lot, about 7 minutes after starting for the first time that day, it died. That was 7 days after visit 4.

I'm nowhere near a mechanic. In fact if I trust you and you tell me to fix my johnson rod, my muffler bearings, and to change my seatbelt fluid I will happily pay you to do so. Everything above is what I know and have been told by two mechanics I trust (well trust enough anyways) and 1 kid whom I paid to do the rear main seal trying to save money (I shouldn't have done that BTW).

I do know I've spent close to 3K since May on it yet it's still not 100% right

Specs on my Yukon are as follows: 02 Yukon SLT, 5.3L, 197,300 miles. Purchased app. 7 years ago with 132K on it. Other than above work everything else has been maintenance. Oil changed every 3K or 3 months with full synthetic. Last change it was 1.5 quarts low after 3 months.

That's pretty much the story. Sorry for the wall of text as my first post. Anyone got any ideas for me to look at? I'm all ears..

 

[swathdiver]

Sounds like a ground wire problem. Check ALL the grounds in your engine bay and make sure they are not loose, not broken, not pinched, not corroded, nor frayed. Start on the left side.

 

[400K_or_bust]

Sounds like a ground wire problem. Check ALL the grounds in your engine bay and make sure they are not loose, not broken, not pinched, not corroded, nor frayed. Start on the left side.

Is that something that a non mechanically inclined person such as myself could do without killing himself or should I just drop it off to the shop and have them do it?

 

[PG01]

You can do it. And btw, stop turning left.

 

[xwt572]

Hello everybody. I just read this thread and can give my findings on the same problem.
For about a year or more, I have had the security light coming on randomly. Nothing else happened, no sudden shut down, no codes, nothing. Just the light.
Thinking it was a door that didn't close enough so it would trigger the alarm to just let the light go on the dash, but not that either.
Until for only a few weeks ago, when I turned back to my car and tried to start it.
Engine turned, but didn't start, which is a clue to suspect the VATS kicking in.
Opened the hood, pulled off the plus wire off the battery for a half minute, and put it back on.
Engine started without problems, and the security light stayed off.
Hooked up my scanner, no codes.
Drove home without any problems, but when I pulled up at my house, which is a left turn, and then a right, the engine just died.
This was the first time in this 1 or 2 years since the security light started coming up every now and then.
Watched a youtube on this one, where they suspected a bad ground from the battery.
Crawled under the front of the car, found the ground, loosened the bolt, cleaned, put it back, and voila.
Not a light ever since.
This was about a few weeks ago, and I have used it to drive about 1000 miles now. This simply was my problem on my 2002 Y XL.
It is the smaller cable from the battery that goes straight down, right behind the front impact bar.
I just can't remember if it was a 8 or 10 millimeter bolt.