2003 Lincoln Town Car 4.6L Misfire: P0355, P0353 Codes After Full Warm-Up in Drive/Reverse
I own a 2003 Lincoln Town Car with a 4.6-liter engine and approximately 125,000 miles. The vehicle exhibits a noticeable engine shake whenever it is at full operating temperature and comes to a complete stop in drive or reverse (any gear) for more than 30 seconds. This shaking mimics a misfire on one or more cylinders. The issue resolves after waiting an additional 30 to 45 seconds, but will reoccur if the vehicle remains stopped for another 30 seconds. I have found that the problem can be prevented by turning on the air conditioning, shifting into neutral while stopped, or avoiding driving at full operating temperature. Previously, I experienced OBD-II fault codes P0000, P0307, and P0306. I replaced the ignition coils for cylinders 6 and 7, cleared the codes, and the issue temporarily disappeared. However, three days later, new codes appeared: P0355 and P0353. I suspect a failing ignition coil or an intermittent circuit issue, particularly under low engine RPM conditions when the engine is warm. I am currently using 93 octane fuel to help reduce misfires and have started routinely placing the vehicle in neutral at stoplights as a preventive measure.
I experienced P0355 on my 2003 Lincoln Town Car with the 4.6L engine. AutoZone diagnosed it and sold me a $35 ignition coil, which I installed in the parking lot. The next day, the code returned. I returned to AutoZone and purchased a $60 ignition coil along with a Motocraft spark plug and dielectric grease. To prevent intermittent coil failure, I now use 93 octane fuel and always shift into neutral at stoplights. I believe the issue occurs specifically under low engine RPM conditions when the engine is warm. I haven't reset the code yet because I need to resolve the underlying problem. I've read many online solutions, but your post caught my attention—both of us drive classic 2003 Lincoln Town Cars. Love the ride! Sincerely, Chris