I recently tried to change the fluid from the power steering. I also installed new spark plugs and replaced the wires. I put everything back together and had not installed everything properly. I had an MAF sensor fault code and replace the MAF sensor The check engine light came on and I just returned the MAF sensor. Put the old one on because the old one was working better. I found that my valve cover needs to be replaced as the car oil was so low wasn't even on the dipstick. My radiator fluid was low as well. Every time I rev the engine, a weird whining sound comes from the fuel rail. I made sure that all the vacuum lines are connected right? The PCV valve line looks like gunked up so I bought a new PCV valve and will replace the hose as well. I'm not sure this will fix the whining sound. I have a 2005 Hyundai Tiburon SE The car temperature gauge is bouncing up and down. I replaced the radiator over a year ago but the mechanic didn't want to replace the thermostat. My car has a new water pump and timing belt.