I have 2004 Expedition EB with 4.6L. I recently passed 100K miles and the Service Engine Soon Light came on...the engine runs fine ....gas mileage has'nt changed ....this is first time I've seen this light come on since I bought the vehicle new in '04. Has anyone else experienced this? Is the service engine soon light set to go on at 100K miles even if there is no engine problem? What is the fix?

 

Get your fault codes read and then research those..

 

yeah what project said.. i have an 05 Expedition with 50k and i bought new and i've never seen the light come on, i have an 02 F150 with 150k that i bought new and the light came on the other day and i took to the dealer and they changed the spark plugs and the light went away

but we can't tell you what's really wrong you just need to get it checked it could be the smallest thing or it could be something very bad, like my uncle has been driving around for the last 10k miles with that light on and his truck is still okay

 

Take it to Autozone or any auto parts store and they should read the codes for free for you. Then research them like projectSHO said.