Engine shakes when car starts- please advise!
I have a weird problem. I have an old car, 94 Subaru Legacy, 175k miles, etc. Its getting worn out.
Anyways, lately when I have been starting the car in the morning, it starts fine as always, and as always the rpm will go up and down a bit in the 1000-2000 range, as per normal. A few seconds after starting though, the rpm will suddenly drop down near zero and the front of the car will start shaking violently. Then, a few seconds later it will right itself, and the rpm will go back up to normal levels. Can anyone give me an idea of why this would happen? It seems to have started on cool mornings, but not cold, so I am afraid of what will happen when the winter really rolls around. This only happens in the morning so far, after the car has been sitting 12+ hours. Doens't happen after work though, when the car has been sitting for like 12 hours.
Can anyone clue me in to some possibilities? I don't want to take it to my mechanic yet, as I always feel like they are screwing me.