4.0L SOHC Engine Swap... 97/98/99/00/01/02/03 Motor Interchange

Gannz · 07-23-2007, 02:41 PM

Hey all,

I have a clean '98 Explorer 4x4 w/ a 3" body lift on 30" Cross Terrains. At about 150k it started a rattle in the rear cassette. New tensioners didn't help & I opted not to pull the motor, buy the tools, and change out the timing cassettes. So we drove on... and on... and on... and I was about to tell people Ford made a diesel Explorer. Then, last week at 190k, she finally jumped time and bent the valves.

So, I need to change out the engine. I have some questions but I'll try to contribute some consolidated info first. This is what I've been able to gather from mainly searching the board...

Here are the different engines available for the years in question:

1997-2000
6-245 (4.0L), SOHC (VIN E), 4x2
6-245 (4.0L), SOHC (VIN E), 4x4
2001
6-245 (4.0L, SOHC), LHD, exc. flex fuel; (VIN E); Sport Trac, thru 7/23/00
6-245 (4.0L, SOHC), LHD, exc. flex fuel; (VIN E); Sport; thru 7/23/00
6-245 (4.0L, SOHC), LHD, exc. flex fuel; (VIN E); Sport Trac, from 7/24/00
6-245 (4.0L, SOHC), LHD, exc. flex fuel; (VIN E); Sport; from 7/24/00
6-245 (4.0L, SOHC), LHD, exc. flex fuel; (VIN E); exc. Sport and Sport Trac
2002-2003
6-245 (4.0L, SOHC), (LHD), exc. flex fuel; (VIN E); 4 Dr, exc. Sport Trac
6-245 (4.0L, SOHC), (LHD), exc. flex fuel; (VIN E); 2 Dr (Sport)
6-245 (4.0L, SOHC), (LHD), exc. flex fuel; (VIN E); 4 Dr, Sport Trac

'97-'03 will all interchange. Some things are different in all of these years. Most are minor. Don't change out your ECU.

1997-2000 would be the most direct swap but you'll have to deal w/ the timing chain issues all over again. With these years you need to match 2wd/4wd to your vehicle.
2001 you need to use your old upper intake, wiring harness, and cam sensor. Timing is still a problem w/ these engines.
2002-03 reuses the same parts as '01 but you'll also need to reuse your old fuel rail (including your old injectors). This makes for a little more work but it seems to be worth it b/c '02 is when Ford finally improved the timing casettes.

Gannz · 08-07-2007, 03:30 PM

I recently finished my ‘98 to ‘03 swap and everything is working as it should.

There are a few more things (other than what’s listed above) that are different about the engines…

You have to use your old exhaust manifolds. The newer manifolds use studs instead of bolts but that’s not a big deal. What is a big deal is that the studs are spaced further apart and they won’t fit the flange. Anything can be modified but it won’t be worth your time and effort to make the new manifolds fit unless your old manifolds are warped or cracked. You also need to use your old EGR valve, bracket, and pipes.

You can save some time if you use your old valve covers. I chose to go with the new covers and I like how it turned out but there was a good bit of modifying necessary to get everything to match back up. The coil pack, upper radiator hose, PCV valve(s) (mine now has two and an extra line), spark plug wires/mounts, DPFE sensor, and the main electrical harness connector bracket all need to be modified. If you use your old valve covers all of these will match up as on the old engine.

The older engine emission system circulates air through a freeze plug knocked out of the block above the crank. The new engine circulates from the rear of the drivers side valve cover. I suspect Ford eliminated the crank breather b/c it clogs over time. I instead set up mine to use both which should make for better circulation and also provide a backup in case one line clogs. If you keep the crank breather (you have to keep it if you use your old valve covers) it would be a good idea to clean it the next time you change out the intake manifold gaskets.

The cam sensor, oil pressure sender, and block ground appear to be the only sensors/connectors you’ll need to use from the older engine. I used all the sensors from the newer engine except for these three.

You need to use your old heater hose bracket/coupling.

The oil filter is different and you need to get filters to fit an '02/'03.

Gannz · 08-07-2007, 07:09 PM

Some photos...

explorerjim · 11-23-2007, 04:52 PM

Great information. I have a 97 explorer, 4 wd. 4.0 sohc engine. I just picked up a 99 4.0 engine today for it. Right away I see I have 2 fuel lines on the 97 and only 1 on the 99 engine. I've read somewhere about using the old fuel rail and maybe the old injectors too. Can anyone help or give me a link to where I read this? I'm not sure what to use from the old engine and still get the the computer to work right when I start it up. I switched a 2000 into a 2001 last year and all I had to do is plug it in and it ran like a top. This one's a little more complicated.

07-23-2007, 02:41 PM	#1
Gannz Wannabe Elite Explorer Join Date: Jul 2007 Posts: 11 Vehicle Specs (Original Poster)	4.0L SOHC Engine Swap... 97/98/99/00/01/02/03 Motor Interchange (w/ photos) Hey all, I have a clean '98 Explorer 4x4 w/ a 3" body lift on 30" Cross Terrains. At about 150k it started a rattle in the rear cassette. New tensioners didn't help & I opted not to pull the motor, buy the tools, and change out the timing cassettes. So we drove on... and on... and on... and I was about to tell people Ford made a diesel Explorer. Then, last week at 190k, she finally jumped time and bent the valves. So, I need to change out the engine. I have some questions but I'll try to contribute some consolidated info first. This is what I've been able to gather from mainly searching the board... Here are the different engines available for the years in question: 1997-2000 6-245 (4.0L), SOHC (VIN E), 4x2 6-245 (4.0L), SOHC (VIN E), 4x4 2001 6-245 (4.0L, SOHC), LHD, exc. flex fuel; (VIN E); Sport Trac, thru 7/23/00 6-245 (4.0L, SOHC), LHD, exc. flex fuel; (VIN E); Sport; thru 7/23/00 6-245 (4.0L, SOHC), LHD, exc. flex fuel; (VIN E); Sport Trac, from 7/24/00 6-245 (4.0L, SOHC), LHD, exc. flex fuel; (VIN E); Sport; from 7/24/00 6-245 (4.0L, SOHC), LHD, exc. flex fuel; (VIN E); exc. Sport and Sport Trac 2002-2003 6-245 (4.0L, SOHC), (LHD), exc. flex fuel; (VIN E); 4 Dr, exc. Sport Trac 6-245 (4.0L, SOHC), (LHD), exc. flex fuel; (VIN E); 2 Dr (Sport) 6-245 (4.0L, SOHC), (LHD), exc. flex fuel; (VIN E); 4 Dr, Sport Trac '97-'03 will all interchange. Some things are different in all of these years. Most are minor. Don't change out your ECU. 1997-2000 would be the most direct swap but you'll have to deal w/ the timing chain issues all over again. With these years you need to match 2wd/4wd to your vehicle. 2001 you need to use your old upper intake, wiring harness, and cam sensor. Timing is still a problem w/ these engines. 2002-03 reuses the same parts as '01 but you'll also need to reuse your old fuel rail (including your old injectors). This makes for a little more work but it seems to be worth it b/c '02 is when Ford finally improved the timing casettes. Last edited by Gannz; 08-08-2007 at 10:59 AM. Reason: New info

08-07-2007, 03:30 PM	#2
Gannz Wannabe Elite Explorer Join Date: Jul 2007 Posts: 11 Vehicle Specs (Original Poster)	I recently finished my ‘98 to ‘03 swap and everything is working as it should. There are a few more things (other than what’s listed above) that are different about the engines… You have to use your old exhaust manifolds. The newer manifolds use studs instead of bolts but that’s not a big deal. What is a big deal is that the studs are spaced further apart and they won’t fit the flange. Anything can be modified but it won’t be worth your time and effort to make the new manifolds fit unless your old manifolds are warped or cracked. You also need to use your old EGR valve, bracket, and pipes. You can save some time if you use your old valve covers. I chose to go with the new covers and I like how it turned out but there was a good bit of modifying necessary to get everything to match back up. The coil pack, upper radiator hose, PCV valve(s) (mine now has two and an extra line), spark plug wires/mounts, DPFE sensor, and the main electrical harness connector bracket all need to be modified. If you use your old valve covers all of these will match up as on the old engine. The older engine emission system circulates air through a freeze plug knocked out of the block above the crank. The new engine circulates from the rear of the drivers side valve cover. I suspect Ford eliminated the crank breather b/c it clogs over time. I instead set up mine to use both which should make for better circulation and also provide a backup in case one line clogs. If you keep the crank breather (you have to keep it if you use your old valve covers) it would be a good idea to clean it the next time you change out the intake manifold gaskets. The cam sensor, oil pressure sender, and block ground appear to be the only sensors/connectors you’ll need to use from the older engine. I used all the sensors from the newer engine except for these three. You need to use your old heater hose bracket/coupling. The oil filter is different and you need to get filters to fit an '02/'03. Last edited by Gannz; 08-20-2007 at 05:36 PM.

08-07-2007, 07:09 PM	#3
Gannz Wannabe Elite Explorer Join Date: Jul 2007 Posts: 11 Vehicle Specs (Original Poster)	Some photos... Last edited by Gannz; 08-08-2007 at 02:15 PM.

11-23-2007, 04:52 PM	#4
explorerjim Wannabe Elite Explorer minn 97 and 2001 Explorer XLT Join Date: Nov 2005 Posts: 15 Vehicle Specs	Great information. I have a 97 explorer, 4 wd. 4.0 sohc engine. I just picked up a 99 4.0 engine today for it. Right away I see I have 2 fuel lines on the 97 and only 1 on the 99 engine. I've read somewhere about using the old fuel rail and maybe the old injectors too. Can anyone help or give me a link to where I read this? I'm not sure what to use from the old engine and still get the the computer to work right when I start it up. I switched a 2000 into a 2001 last year and all I had to do is plug it in and it ran like a top. This one's a little more complicated.