I have a 2005 prius, and it has developed a severe vibration when the engine is running. It is only when the engine is running, even in park. I'm thinking it's the motor mounts, but I was wondering if there could be another cause. I do not have a check engine light, and the engine appears to be running fine. the vibration goes away whenever the engine cuts off, and there are no other drivability issues.
Questions: Is there a difference between the engine making power vs. just spinning as in warp stealth gliding? Does the vibration follow the engine rpm?
Yes, the vibration is most pronounced when coasting or idling. the vibration is trnsfered through the entire vehicle, as if the engine is contacting the frame. I inspected this as much as possible, but couldn't find anything.
If I understand, what you are saying is that when the engine is not making much torque, as in coasting, then the vibration is more pronounced than if the engine is active and making torque, as in accelerating or at speed. That might implicate mounts, as they would be more loaded in the high torque case, which might squeeze a parted rubber together enough to limit vibration. At idle, the mounts are less loaded, and so potentially more loose. Just a guess.
