My Sable is sometimes not firing on all cylinders. It never stop, but
it could go with idle so low that charging light would start blinking.
It is happening after driving for 15 miles (from work), stop for 15
minutes in day care, starting and driving 200 feet to first
intersection with long red light. Then engine starts hesitating on
idle with gear (auto) on. Sometimes even on first few yards of driving
after light. Got it checked in dealer where I have extended warranty.
They did cylinder pressure check and found no problem. My initial
opinion was piston ring or valve is worn, but pressure check should
rule this out. It is happening since I bought the car about 6k miles /
half year ago. Outside this problem engine is fine with good power,
starting, no oil consumption etc. On idle engine does not vibrate as
evenly as my other car, but that may be normal. It does have 12 valve
155 HP engine with 40k miles on it. I can as well do nothing about it,
but wondering about effects in long run.