Entire car is vibarting when i started the vehicle, kindly let me know hat would be the reason?

For past 10 days I havent taken my car out all of sudden i have to take my vehicle out for some domestic work.when i stated my car, entire car is vibrating, immediately i opened the car bonnet and i can see the entire engine is vibrating and I can see exhaust sign lights on the meter till the vehicle is on. I cannot see any leakage. Kindly let me know what would be the reason