Since about a year ago, my car started to vibrate in a cold start, and would go away in a minute or so (mostly felt in the interior plastic). Fast forward 6 months, vibration became very noticeable in cold starts, interior panels vibrates heavily and would take at least 15 minutes of driving to calm the vibration. Currently, i do not even feel like driving the car as the vibration is very bad (not heavy shake, but vibration). However, now i have to drive 30 minutes for the vibration to calm down. Now, even after he vehicle is fully warmed , I am still able to feel the vibration in the steering and the interior panels when i go through smooth wavy roads (not offroad), like when there is a smooth dip on the road, this vibration can be felt for that moment. I had checked with mechanics who is aware on how to work with Evo's, but since he is a busy guy and also by the time i reach his garage (which is far), the car would have stopped vibration by a lot. I have replaced spark plugs which did no good. The mechanic also lifted the car, checked all engine mounts and everything was fine as per him. I have searched for this problem generally (for any car) and for evo's in this forum. I was not able to find any answer. Any technical guy out here who can help

 

Start with a boost leak test.