'97 to '02 SOHC engine swap???

[gusman]

howdy,I would like to know why I can't replace my 97' 4.0 sohc with an 02' 4.0 sohc.I picked up the 02' from a local,trustable,salvage yard only to find out a week later that he must have "punched in a wrong number".Now he tells me that his computer says it won"t work.It sure looks to me that if I switch all the exteriors of my 97" to the 02" it would work.Is it a sensor location problem or computer or the way it bolts up?I can't get an answer on why it won't work.Anybody got a good answer? Sure would appreciate it.

 

[Rick]

I'm going to move this to the stock 1995-2001 Explorer Forum. My first hunch is that yes you can swap all the sensors and it will work. There's just one thing I'm not sure of and that's the cam position sensor. I think that sensor was added midway through the 2nd gen run.

Welcome to the site:

 

[410Fortune]

all SOHCS have a cam position sensor
the difference between the 02 SOHC and a 97 SOHC is the plastic intake plenum and the fuel rail.

You will want to park both engines next to each other, strip the 02 down to the lower intake, and use the wiring, fuel rail, and sensors from your 97 engine.

The 02 model uses a returnless style fuel rail, the earlier models use a vacuum controled pressure regulator and return line

 

[Geeshik]

The '02 doesn't have a lower intake at all. The upper intake bolts right to the heads. Ford puts a piece of foam wrapped in plastic in the valley under the intake on the '02. If the heads are the same, this shouldn't be a problem. Definitely check the bore size / depth for the injector holes in the cylinder heads as you might be able to just drop your intake and fuel system onto that engine. Ideally you would not want to mess with the fuel tank and fuel lines.

I think the valve covers and exhaust manifolds are different too. I thought about swapping the other way because it's alot harder to find the '02 up engines around here, and the difference is about $600. I have also heard of different bolt patterns on the crank (6 or 8 bolts), piston differences, and a few others, but they can't be that different from each other. Ford used both engines in the same year, one for the sport/sport trac models, and one for the 4 door explorer.

 

[kevinspann]

Yes, but you'll have to swap over everything external.

Oil pan including the pick up (if yours has a low oil sensor) , valve covers, intake, PCV...basically transfer everything bolted to the outside of your engine.

I have an '04 Ranger engine in mine.

 

[snoranger]

I have to assume he got this all sorted out in the past 5.5 years