After my big trip back from Atlanta to Austin after I was laid off Friday from my Atlanta assignment, I went out again today in the SSR to tow one of my motorcycles to a bike shop, and suddenly, on the freeway at 60 mph, got an "engine light".
When I came to the end of the ramp at my exit and idled at the light, the idle was VERY rough - so rough that when I took my foot off the brake, the whole truck shuddered as it tried to creep.
Power accelerating was notably reduced. It felt like it was firing on a LOT less than 8 cylinders.
The engine light was constant when idling, and flashing when actually driving on the road. There were occasional backfires, especially on deceleration, but sometimes even at light cruise.
I assumed that somehow I must have lost the spark to multiple cylinders, that's how bad it felt.
I took it in to my Chevy dealer an our later, and prepared for bad news.
After just 20 minutes, my service advisor returned and said "Ok, it's all fixed and already moved back to the driveway for you to pick it up!"
When I asked what had caused those intensely negative symptoms, I was told that ONE spark plug wire had slipped off its plug a bit, and so was misfiring.
Can you believe it? ONE bad sparkplug wire connection did all that? Makes you realize how precisely tuned modern engines are.
Guess I know where to look if it ever happens again . . .