05 Malibu 3.5 L automatic. Runs good from 0-54 miles/hour. Suddenly above 55mph runs rough&shakes.
Feeding a lot of gas above 54 mph often smooths out the shake, and
CAN make it run smoothly if you accelerate "just right." Then immediately
shakes when coasting back to 55 mph.
1. Feels like engine is missing at 54+mph
2. Also the right front tire is now very worn out. Outer edge now fraying to
the steel belt. Need alignment and maybe tie rod?
But engine problem was ongoing before the tire became so obvious. Or
could the engine roughness above 54mph be the only problem?