Q: I have a 2000 Mercedes c230 komp..that had been in fairly good condition..until about 2 weeks ago.

I have a 2000 c230 Mercedes and just recently it starting not cranking up...so my bf tried a couple things and figured it was the fuel pump...after he changed the fuel pump and cleaned out the filter...the car started up! But then it was sounding raggidy and then started overheating out the blue...I took it to a shop at this point and they said I had a blown gasket...now I'm trying to figure out how did I go from fuel pump to blown gasket when my water pump was new not leaking and fuel pump just been replaced???? Could my bf have done something malicious??? Just asking cause this is bizarre and now I have to get a new car or pay 2500-3500...
My car has an automatic transmission.