Hi. There is a TSB for your vehicle for this concern. It is quite common. You need to replace all six ignition coils and spark plugs. You may also have to replace the PCM ( vehicles main computer ). Here is a copy of the TSB.
This article supersedes TSB 09-2-6 to add a production fix date, update the Service Procedure, Part List and Service Labor Time Standards.
Some 2005-2006 Escape and Mariner vehicles built on or before 10/3/2005, equipped with a 3.0L engine may exhibit a malfunction indicator lamp (MIL) on with two or more diagnostic trouble codes (DTCs) for coil on plug (COP) primary circuit faults (P0351 through P0356). This may be due to the COP and powertrain control module (PCM) reacting to radio frequency interference from the spark plugs.
Follow the Service Procedure to correct the condition.
I can replace parts but would you recommend that a dealer look at it? The vehicle has 109,000 miles and this sounds like a defect "Radio Intefernce from the Spark Plugs"
does the dealer repair this under warranty. Almost sounds like a recall should have happened.