cherokee motor swap

[93YJ]

The I6 4.0 liter motor in my 1990 xj Cherokee seized up and I am in the process of trying to replace it. Does anybody have any good write ups or links to write ups that give a step by step process for taking the motor out and then replacing it with another I6. There are so many sensors, wires hoses that it looks like the space shuttle blew up in the jeeps engine compartment LOL! This is my first motor swap and it is looking pretty intense to say the least! Any help on the process would be very much appreciated Thanks.

 

[TooeleBronco]

Mark every wire and vacuum hose and where it went. When you pull the engine leave it right there to see where everything came off to match to the new motor. When you have it out I'd replace the clutch (standard) or the pump seal (automatic) or anything else you can see that's right there. It's not real hard to replace but the hardest thing will be the wiring and vacuum houses. Also don't force the engine and tranny together with the bolts. You need to be sure everything lines up before you tighten it down. I've seen bell housings break if it's forced.

 

[4x4_Welder]

Wiring's easy, it's just a couple of plugs. AMC SUCKS at vacuum stuff, and Chrysler didn't take care of that until quite a bit later, so you really need to take your time and mark all the hoses. Napa has kits of stick-on number labels just for this purpose.
The whole grille, radiator, and bar across the top of the radiator support comes out to allow the engine to be removed.

 

[iamsparticus]

Label everything and get a diagram of the vaccum or you will forget even with labels, oh and a trick a good friend taught me is take lots of pictures for reference as you take it apart so you can look back and say oh thats how it looked

 

[93YJ]

Any suggestions on motor mounts? Type, cost, durability, etc. I also have a borla exhaust manifold from the 90 motor that was pulled. When I pulled it off the gasket had a crack. Can I put that on the 93 motor going in? And how much can I expect to pay for a new gasket?

 

[bobmed]

Label everything and get a diagram of the vaccum or you will forget even with labels, oh and a trick a good friend taught me is take lots of pictures for reference as you take it apart so you can look back and say oh thats how it looked

The pictures will help a lot.
I used to use a polaroid camera when I rebuilt industrial machines.
Digital iss even better.
Get pictures from as many different angles as you can.

 

[DaveB]

We are swapping out a 4.0 in my son in laws cherokee, if you want to stop by I can show you what to do.

 

[93YJ]

I am wrapping up this motor swap and making sure all of the sensors etc are in place. The motor is out of a 93xj OBDI. The 90xj renix has the 4.0 I6 coolant temp sensor on the driver side on the block. What tool and size do I need to get the plug out to put the renix sensor back in?

 

[DaveB]

I am wrapping up this motor swap and making sure all of the sensors etc are in place. The motor is out of a 93xj OBDI. The 90xj renix has the 4.0 I6 coolant temp sensor on the driver side on the block. What tool and size do I need to get the plug out to put the renix sensor back in?

There are two temp sensors on the 91-95 4.0 engines. The front one is on the thermostat housing and the rear one is on the back of the head on the drivers side. Both just screw out using a socket or wrench. The one in front runs the computer and the one in back runs the gauge in the dash. You should be able to take out the ones from the newer engine and swap them with the Renix sensors from your old engine. If you don't have the original sensors take a trip to the TearAPart. The rear sensor is different if you have a real gauge or an idiot light so you will want to make sure you match what is in your Jeep.

 

[gijohn40]

I just paid a friend who started his own auto shop to do my son's... he only charged me $350 to swap out the old and put in the new... if you want the number he sure could use the business.... one other thing you could do is seeing that most the sensors are on the intake manifold you could just remove it from the old engine and try to move it to the side and then replaced the engine and mount it back up this would help some in keeping the sensors where they belong...

 

[93YJ]

Thanks for the heads up on the shop gijohn40. But I have actually put the motor back in and I am just wrapping up the swap this weekend. I am just making sure the coolant sensor is put in the write place on the block for the RENIX computer. The block was out of a 93 going into a 90. The 93 coolant sensor is on the thermostat housing but the 90 is on the engine block driver side underneath the manifold.. I needed to know what socket size I needed to get the plug out. 5/16 square drive is what I am looking for I guess.

Another question that has popped up. I have a borla exhaust on the motor. I have tried to put the knock sensor back in the location that the original motor had it (driver side back of the block just above the oil pan.) The exhaust manifold is slightly covering it making it impossible to put the knock sensor back in that port. I noticed in front of the manifold there is a similar threaded port with nothing obstructing the hole. Could I put the nock sensor in there? So I kneed the knock sensor?

 

[DaveB]

Thanks for the heads up on the shop gijohn40. But I have actually put the motor back in and I am just wrapping up the swap this weekend. I am just making sure the coolant sensor is put in the write place on the block for the RENIX computer. The block was out of a 93 going into a 90. The 93 coolant sensor is on the thermostat housing but the 90 is on the engine block driver side underneath the manifold.. I needed to know what socket size I needed to get the plug out. 5/16 square drive is what I am looking for I guess.

Another question that has popped up. I have a borla exhaust on the motor. I have tried to put the knock sensor back in the location that the original motor had it (driver side back of the block just above the oil pan.) The exhaust manifold is slightly covering it making it impossible to put the knock sensor back in that port. I noticed in front of the manifold there is a similar threaded port with nothing obstructing the hole. Could I put the nock sensor in there? So I kneed the knock sensor?

The knock sensor hole is a metric thread and I don't think there are any similar sized holes on the block but there could be. The knock sensor is a microphone that picks up pre-detonation on these motors. You will want it so that it won't ping. By the way the motor you got from my son in law is a 95. If you could thread another piece of metal with the metric thread you could make an adapter which would let you bolt it in another spot on the block. On the temp sensor you could adapt it to fit in the newer location by changing the wire length.

 

[93YJ]

The knock sensor hole is a metric thread and I don't think there are any similar sized holes on the block but there could be. The knock sensor is a microphone that picks up pre-detonation on these motors. You will want it so that it won't ping. By the way the motor you got from my son in law is a 95. If you could thread another piece of metal with the metric thread you could make an adapter which would let you bolt it in another spot on the block. On the temp sensor you could adapt it to fit in the newer location by changing the wire length.

Cool thanks Dave!!!