I just bought a used car. I didn't pay very much for it, but was guaranteed that it would be in completely working condition. Before test driving it, i was told the only problem was the A/C needed charged. When I took it for a test drive (also on the highway so i could get it up to speed) i went with my mechanic. It obviously had an oil leak (i could smell the burning oil) and the speedometer was jumping. The guy then told me that it had a minor oil leak, but he would fix it. And, i checked prices for Speed Sensors and they only ran about $40.. so i thought i was getting a great deal on the car. Well, i was driving about 30 miles from home, when my car started jumping then smoking. I quickly pulled off the road and found out i had a HORRIBLE oil leak coming from 2 places! Could it just be the Valve Cover Gasket wasn't fitted right or what else could be the problem?? I would greatly appreciate any/all help and advice. I don't know anything about cars, and i don't really want to have to take it to the mechanic if it's something small that i could have my brother fix.