My 2014 forester starts to vibrate over 40 mph. Under 40 mph it is okay. Any suggestions? Thank you
I don’t suppose you have considered wheel balancing and an alignment.
Does it vibrate when you accelerate, when you coast, or both?
… and, does it vibrate when you drive at a steady speed of more than 40 mph?
That is entirely possible, but if somebody truly desires help with his vibration problem, would it make any sense to omit a refence to an illuminated CEL?
My intentions were to ask OP if there was a check engine light. The above should have said " is the check engine light on?" Anytime I here of a vibration starting at 40, my first thought is misfire.
My first guess on this symptom would be “tires damaged in a pothole OR out of balance”.
Other posters gave here a good set of tests like checking if vibration is any different when cruising / accelerating / decelerating, as it would help to get an idea if this is something in a driveline.