I want to be able to fix this stuff myself, so I'm posting here hoping someone can give me some help on this stuff. First off, about a month ago, my car started rough idling. It would go on and off for awhile but it's always rough on idle and my engine sputters slightly when I'm accelerating. Just today I heard a rattle below my car also, Mostly when I'm accelerating at the first gear. On the rough idle problem it's been suggested to me to g et a tune up, I.E. spark plugs, cap/rotor...I checked my air filter...It's fine...Let me know what suggestions you have though for these problems. Thanks for taking the time...

 

You could try new spark plug wires for the rough idling. The rattle could be a loose cayalytic converter cover. How many miles are on the engine?

 

The engine is around 3 or 4 years old. It a newer V6. The rattling started a month ago...

 

Goingstrong, YOu answered both questions perfectly. I changed the plugs, cap/rotor and there is no idle/sputtering anymore. It drives great. I got my oil changed and asked a guy at modern tire what the shaking sound was on the bottom of my car. He first said it was the exhaust shield cover then looked on the other side of the car and said it was a hole in the cayalytic converter. I asked my father though about this and he said you don't get holes through the cayalytic converter...Either way, thanks for the help. Let me know how the cayalytic converter though and how I would go about getting the cover to not rattle...

 

Usually the cover is welded on. Rewelding is the best option for that. Other things can also rattle on a car but this is the most obvious. Could also be a loose exhaust clamp, loose fuel or brake line, or an engine bearing going bad. If it were an engine bearing in trouble it will make a much louder noise if you hammer on the gas from a dead stop.

 

Also if you have a 3.8 V6 keep an eye on the oil pressure. The pumps had metal gears in a softer aluminum case and the case can wear early (steel sleeves implanted would help).