I have a 2001 STS with 50,000 km on it (bought used at 45,000 km). When the engine is cold, I hear the distinct sound of one or more sticking lifters.
I added top-end clearner to the oil and it certainly improved, but is still there. I've taken it to the dealer who de-carbonated the engine (no change).
What else can I do? What would be the impact of a sticking lifter longer term?
Thanks Mike