4.6L 2V intermittent misfire turned into severe shake/stall
shop says 40-70 PSI compression on multiple cylinders & demands replacement. Slipped timing or fuel wash?
two weeks ago, my 2006 Grand Marquis started to idle rough while in a drive thru, like it was about to turn off, but stopped after 5-10 seconds. Then a few mins later as i was wrapping up at that drive thru and accelerating to leave, the car hesistated for a brief second then was normally picking speed after. This happened maybe 3-4 times since then. Then yesterday, I started the car up to go to class, it was fine but on my way back later, when I started it, it had a constant, severe misfire, stalling at stops, and heavy engine shaking. A shop scanned it and traced the primary issue to Cylinder 2, but when they pulled the coil plug, the rough idle smoothed out slightly. They performed a compression test and found 40–70 PSI across multiple cylinders, said the car was running on 7 cylinders, immediately declaring the motor dead and recommending a full replacement. However, the engine has no heavy knocking or rod knock (it just has a full exhaust so it sounds a bit like it’s knocking in the video but it’s not), it sounds like it's running on fewer cylinders. Before replacing the engine, could this be something smaller?