I'm new to this site and I'm using it on my phone so I have no clue if I am posting this right because my phone is running so slow but... I have a 2007 Dodge caliber * w. about 120,000 miles.... about a month ago I drove somewhere that is about 15 miles away from my house... once I got to my destination a loud knock was coming from what I would guess would be the engine. after I finished my errands I prayed to God and drove it home thinking the engine was going to blow at any second. luckily, the car made it back to my house without breaking down. the knock was LOUD and not as noticeable past 60mph... I don't know a thing about cars. all's I know is... it is my parents car that I was driving on a daily basis for about 3months before this happened. the oil light came on when it happened... and about 4 days before this happened I threw a quart of oil in it cuz the llight turned on... when I did that it turned of and stayed off til the day the knocking started. I have No clue when the car had its last oil change. my parents are notorious for not changing the oil in their cars... and it hadn't had one in the 3months I drove it so I'm guessing it went 10-15000 miles without one before the knocking started... maybe more.I just want to get some type of knowledgeable opinion before doing anything w.the car. it hasn't been driven since... it still runs though... I was sure it was the engine about to blow, my dad insists that its possible it just might need an oil change, but as much as he wants to think he is, he isn't a car Guy, at all. also, the a/c doesn't work... don't know why or if that's relevent, just thought I'd add that in there. any helpful opinions, suggestions, or tips? please help!!!!