Does 4.2l engine from 1998 f150 interchange with 4.2l engine from 2003 f150?

Answer 1

Yes it is interchangeable .The 2003 is a better engine as the crankshaft has five main bearings on it while the 1998 model only had four . All the faults that were found on the 1998 model were corrected on the 2003 model .Some people reuse the 1998 intake manifold and injectors when they change over to a 2003 engine as they feel that not doing so would have adverse effects on the computer and onboard diagnostic system .I don't believe that this is the case . I own a 1998 4.2 F150 and I changed the engine out for a 2003 model and have had no problems . Make sure that if you have a new alternator and starter on your old engine that you change them over before refitting the new engine .You may as well replace the serpentine Belt at the same time while you are at it .The 1998 was well known for water leaks into the cylinder head ,filling up the cylinder on top of the piston and when you started the engine the hydraulic lock caused when the piston tried to compress the water would result in a bent connecting rod resulting in a heavy knocking sound from the engine or sometimes breaking the rod and sending it through the side of the engine block .