Swapping a 97 ohv to a 99

[Josh1254]

My explorer has a head gasket leak with 136,000 miles on it. Starts and runs but is a little rough. I have a motor lined up to buy out of a 1999 explorer that was slightly rolled. The motor has very lows miles and should work perfect. Im just wondering what problems I may run into swapping them, and if it will be a direct replacment or not. Any information would be appreciated.

Thanks

 

[Blee1099]

I think you'll run an issue with the fuel system.. I believe 95-97 or maybe 98 was a return fuel line system and the 98 or 99 to 2001 went to a returnless fuel system.

 

[99SportX]

I think that if you swap all the fuel rails, some sensors, and probably wiring over onto the 99 motor that it would work, as I don't really think the basic engine changed at all. I do know that the plastic upper intake did change design slightly between the 95-97 or 98 and 99-01 years though. I think it was only cosmetic though, not really a major design change.

I have never done this, but I am just throwing my thoughts out there. Maybe someone knows 100% for sure what to do.

 

[410Fortune]

yes 99sportx nailed it


use the 99 4.0L block. heads, lower intake
Use the 97 upper intake sensors, fuel rail, wiring, etc.

Believe it or not this question is asked ALOT (similar) so you can try a search for this topic.

I hope the 97 and 99 engines are both either the 4.0L OHV or the SOHC?

You can put a 2001 OHV 4.0L into a 91 Explorer in the same manner, if that gives you an idea of how much the basic long block changed over the years.....

 

[Josh1254]

Yes they are both OHV. I did see some other threads but none about swapping a later model OHV with another, just wanted to make sure there was nothing I was overseeing considering its my first swap.

Thanks for all the help

 

[bigandbadranger]

i thought the early 4.0's were a 6 bolt flywheel and the later were 7 bolt.

 

[Heavymentill]

i thought the early 4.0's were a 6 bolt flywheel and the later were 7 bolt.

97 and later have 8 while earlier years had 6

 

[Josh1254]

Well I will be picking up the motor this week. I will post pics and let everyone know how it goes. Hopefully it will all go well. Thanks for the help everyone

 

[Josh1254]

Well I am half way done with this. Today I got the old motor out, took off the upper intake, fuel rail, and wiring harness. The only thing I am using from the old motor is the wiring harness and fuel rail. The plastic upper intake was exactly the same as the older one, I checked the part number and it was the same.

 

[410Fortune]

sweet

 

[Josh1254]

well it looks like I spoke too soon..

the camshaft position sensor is giving me problems. My wiring harness from the 97 uses 3 wires, red, blue/orange, and a ground. The new 99 motor camshaft position sensor uses 2 wires that are red/grey and blue/orange.

Any ideas what to do? This is the last thing keeping my motor from going into the explorer!!

 

[Josh1254]

anyone??

 

[Josh1254]

I finally got this figured out and have the motor in and running. Everything seems like its fine but I still have one trouble code to deal with.

PO171 and PO174

Im not sure why both banks are running lean. The o2 sensors have 10,000 miles on them, I installed new upper intake gaskets when Installing the fuel rail, I have looked all over for a vacuum leak, and when I unplug my MAS it runs worse, so I believe its working.

The truck idles great after it runs for about 15 seconds, it stumbles a little bit when I first start it. Also when I go to give it gas it stumbles or hesitates for a second. Not sure if any of that will play a part in anything. Anyone have any ideas of what else to check?

BTW I did have this same code before with the old motor, I dont know if its a coinsidence or what, but Im very confused with it right now.

 

[Josh1254]

anyone?

 

[explorerjim]

Did you ever get this all together? I'm trying something similar and wondering.....

 

[Josh1254]

yea i had something with the o2 sensor wiring left unplugged that caused the error codes. let me know if you have any questions about the swap

 

[vroomzoomboom]

hi there, if i am reading this thread correctly, should i be able to do this. i have a 90 ranger 4x4 with a 4.0L in it that is dying a very slow death. i also have a 00 explorer 4x4 with a ohv 4.0L in it. both are auto. ranger has about 375 kms on it. the explorer has 125kms on it. should i be able to take the explorer motor (long block) and use it in my ranger? please let me know because even though it is a old truck, it is very reliable.

 

[explorerjim]

Thanks for the info Josh1254. I'm swapping a 99 sohc into a 97 sohc. I've switched the fuel rail and injectors from the 97 into the 99. Almost ready to pull the engine and replace. The old engine was locked up so that added some more fun. Just have to get it in and then figure out the vacuum lines. The old engine was partly pulled apart when I bought it so the vacuum lines I will be redoing from the little diagram above the grill. Sounds like fun!