car runs fine at cold start but after few miles it hiccups as if it is running lean.No check engine message received and nothing on computer readout.
Take it out on the highway and floor it for as long as you dare…If it’s something serious, this will usually force the issue and set a code (CEL will come on)
If it runs smoothly during this procedure, I would suspect an EGR problem. Disconnect it and see if that cures the “hiccup”…(disconnecting it will cause the CEL to come on but that can be ignored for a day or two)
I believe this is the same engine used in recent Thunderbirds and the motor has individual ignition coils on each spark plug, COPs. These coils go bad and the hiccups you discribe could easily be misfires. It takes a lot of misfires before a bad COP or several bad COPs will throw a code and turn on the check engine light.
I had many problems with COPs on my '04 T’bird, as have most T’bird owners, and finally got Ford to replace all of them under an extended warranty program they have for T’birds. It is likely your car may still be covered under a similar program for Lincolns.
The earliest COP failures are rare before 20K miles, start to occur at 30K, and often fail by 50K miles and up.
These COP’s are common to ALL modern Ford engines and they can be troublesome… A high-pressure wash is the kiss of death…By doing the full-throttle acceleration, the problem usually becomes severe, codes are set which will point out the one(s) that have failed. They cost $80 each, so you don’t just “throw a new set in”. I purchased a used set on E-bay to cure a problem I had and now I have a few spares…If this turns out to be the problem, replace the spark-plugs too…
The spark plug coils have been replaced on 4 cyls…I know how they feel when they are bad…This sounds more like mixture as it runs perfect when cold.(owner)