Ford Repair: 97 grand marquis sudden power loss, low oil pressure, coolant level

Question
Driving my 97 grand marquis home this evening on I-95. Upon accelerating it began to rumble and shake and seemed to lose power, check engine light flashing. I immediately pulled into a rest area parking lot where it stalled and would not start again. Called my insurance roadside assistance coverage. The tow truck guy said it sounded like a fuel pump from my description. He reached under with a metal bar and tapped on the gas tank while I cranked the engine. It started, so I elected to drive it the rest of the way home (30 miles). I drove 55 mph on cruise control but the engine didn't sound right; very noticeable pinging or tapping. The engine roughness continued but got more noticeable going up an incline and less noticeable going down. Near home I noticed the oil press. gauge wasn't registering-at all. So when I got home I checked the dipstick and it was right on the money as was the coolant level. Fuel gauge read about 1/4 tank. Turned the key to see if it would start; it did.  

I also connected a code scanner to get the diagnostic code, which reported "Misfire in cylinder number 4." I started the engine in the driveway this morning. Listening to it at idle or when revving I still hear the pinging or tapping noise.

Any ideas?

Answer
hello there. well when you got stuck there. the driver was right it does sound like a fuel problem. especialy if hitting the tank got it to start. now with this engine noise. any noise is no good. If your fuel pressure was not reading then that is a very big issue. some vehicles are equiped with a safety feature that will disable the fuel pump if it detects low oil pressure. im not sure if it equiped on this vehicle this old. the engine pinging could also be a case of low fuel pressure. that may cause a spark knock. but test the fuel pressure nd let me know waht happens. good luck
Chris P