Chevrolet: 98 chevy lumina, chevy lumina, altanator

Question
I have this 98 Lumina 3.0 with over100,00miles on it. I accidently put desile fuel in it about 4 mounths ago. I replaced the fuel pump and filter. and it was and still is making a kind of soft sirene noise that no mechanic I know has ever heard before. And just a couple of days ago I pulled into a gas station took out my keys went inside to pay for gas pumeped it got into the car and it would not krank not even a light would come off. so some guy jumped my car off. I went to auto zone and they checked the battery and alternater and told me it was the alternater. I took the alternateer to a shop and the said there wasn't anything wrong with it. I am sick of this car I have spent way more on it than what its worth fixing it I would love to blow it away or trade it in but I am in no position to get a monthly payment started. this car is payed for but it is a pain in the a-- if you know what i mean. Please help?


Answer
Robin;
  Hi , I know you you can get ripped off by some people, I wonder if the altanator  was not charging , it must be checked with a volt meter to see what voltage it is putting out - it should be 13-14 volts when idleing , if 12 or lower -thats not good, as far as the desiel fuel  it should be all out by now , it could have cloged up some sensors but it should all run out , I would put in some dry gas in the gas and also a can of gas treatment , the noise could be from the altanator bearing , if that - the altanator would still charge but it would be the bearing that is bad so it would still have to be replaced. so have that looked at , as far as the desiel fuel you are not the only one that has done that.than if you still have trouble have the car checked on a computer to see what codes come up .  ok