My saab 9-5 2002 is blowing a white smokes from exhaust pipe.

What is your question?

I bought this car from an old man mechanic roughly age late 60s who l so much trust in him. He has never mentioned any problems regardless the car. I have spent almost $3500 on it excluding $1800, I bought it. Both exteriors and interiors are clean. I'm a single mother of 12&8 girls. I am very unhappy and stressful with my situation because its very hard to go around without a car. I had to wake early to drop off my children at school and to go to school as well. I took it to get the road worthy and I was told l need to change couple things which costed me almost $3500. I can't afford to buy another car. I DO REALLY NEED HELP.