A good friend's son had his 2.3l engine go in his 2006 Mariner. My friend found a engine online through a broker and had a local garage install it. It would start but run really rough. My friend asked to look at it since I've had a 2009 Escape Hybrid for 8 years now with well over 325,000 miles and scrapped a 08 hybrid that was given to me by another friend. The first thing I noticed was that the "new" motor is actually a 2.5 not a 2.3. Will a 2.5 work in a '06? Its not throwing any codes but it runs as if it has a miss and won't run for more than a minute or two before shutting off.

 

Can I ask how did you sort this issue out ?