Hi I have 2005 Prius with 95,000 miles and I recently left it parked for about 5 days. When it is in ready mode, its quite for few seconds and as soon as the motor engine starts, there is an extremely loud noise and the car is shaking. Definitely smell fuel when the noise starts. So far, I've turned it on and off about 4 times and every time it's been the same result. I turned it on with the hood up and the noise seems like its coming from pretty deep down toward the windshield but I turned it off because of the fuel smell. I need to move the car before street cleaning tomorrow morning but I'm unsure if I should drive it. If weather has anything to do with it, it did rain few days ago and I did drive less than a quarter mile to move it 5 days ago. There was no problems then.Since then it's been relatively warm during the 5 days left ( low 50s - high 70's). Help!
1. Get under the car and see if someone stole the catalytic converter. 2. If the exhaust system is intact, rev up the engine and see if it runs more smoothly. If so, try to drive the car around the block, and see what happens. 3. If the engine is misfiring, look at the wiring harness surrounding the engine to see if there is damage from rodents, etc. 4. If the engine is misfiring, and since you say the car was rained upon, maybe water dripped onto the engine valve cover and got into a spark plug well. That definitely would cause a misfire.