I just recently bought a 2001 s40 with about 100,000 miles about 6 months ago now its pushing 117,000 miles and causing a few problems. I've maintained necessary fluids and recently changed the ignition coils, spark plugs as well as spark plug wires. It has a starting problem and will crank a few times before turning on, giving a smell of gas. Randomly comes and goes. I also have a large rumble in my engine when im going over 2500 rpms. Battery is fine and charged. want to hear peoples opinions if they had the same problem. People have said I need a new fuel pressure regulator. I wanna save the money of going to the dealership but that might end up being the only option i will be left with

 

You can check the fuel pressure regulator by disconnecting the s-shaped vacuum line just after the engine has run and see if fuel drips out.

 

Mine had the gas smell and long starts. Replaced the Fuel Pressure Regulator and it solved it. As for your other problems, I don't know.

 

+1 on the fuel pressure regulator. Test your fuel pressure first though. The part is kind of expensive these days but it only takes a few minutes to fix it.