4 cylinder to 6 cylinder swap - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Cherokee & Comanche Forums > XJ Cherokee Technical Forum > 4 cylinder to 6 cylinder swap

Savvy/Currie Aluminum Control ArmsROCK BOTTOM prices on LIFT KITS at Rockridge4wd!! WANT TO December Specials at Jeephut.com

Reply
Unread 06-05-2012, 07:36 PM   #1
ZeroGravity
Registered User
1991 YJ Wrangler 
 
Join Date: Jul 2008
Location: Boston, MA
Posts: 3,930
4 cylinder to 6 cylinder swap

I have a 1998 XJ, 2 door, 5 speed that is in very good shape. It has the 4 cylinder motor which was fine when I got it but I'm driving on the highway more often and to be honest I wish it would throw a rod so I don't have to use it any more. I'm getting 14 MPG (I get 16 in my lifted YJ, 4.0) and it's becoming such a pain in the *** to feed, I keep considering getting a small car like a Mini Cooper or a Subaru Impreza. Way off in the back of my head but the thought gets more prevalent each time I hit interstate 95.

The original clutch is beginning to slip. I don't like the AX5 much either so I would like to replace the engine and tranny with a 4.0/AX15 while I'm all up in the guts. So, I would like to know exactly what I would need to do to pull this off.

I have a budget of $1000 and I can do all the work myself. Thanks.

__________________
91 YJ
98 XJ
2 door love
The U.S. Army vaguely envisioned something bigger than a motorcycle, smaller than a truck, and undaunted by the most difficult terrain.
ZeroGravity is offline   Reply With Quote Quick reply to this message
Unread 06-05-2012, 10:33 PM   #2
lsmurphy
Registered User
 
Join Date: Aug 2010
Location: Parrottsville
Posts: 296
2.5s will surprise you when you get it running as it should. I get 24-26 round town.




Buy another XJ, what you want to do isn't worth it in IMO.
lsmurphy is offline   Reply With Quote Quick reply to this message
Unread 06-06-2012, 12:30 AM   #3
lsmurphy
Registered User
 
Join Date: Aug 2010
Location: Parrottsville
Posts: 296
http://www.jeepforum.com/forum/f9/2-...08/index4.html
lsmurphy is offline   Reply With Quote Quick reply to this message
Unread 06-06-2012, 06:41 AM   #4
ZeroGravity
Registered User
1991 YJ Wrangler 
 
Join Date: Jul 2008
Location: Boston, MA
Posts: 3,930
Okay what do I do to get it running good?

Buying another XJ isn't practical because I like the 2 door five speed which are quite rare, at least around here.

I really muddled that first post. My concerns involves the wiring harness in relation to engine performance. If I get the motor from a TJ obviously the wiring harness from the same vehicle isn't going to simply plug in. Would it be possible to modify and use my current wiring harness? I don't know how to tell the computer that my Cherokee it has two more cylinders.
__________________
91 YJ
98 XJ
2 door love
The U.S. Army vaguely envisioned something bigger than a motorcycle, smaller than a truck, and undaunted by the most difficult terrain.
ZeroGravity is offline   Reply With Quote Quick reply to this message
Unread 06-06-2012, 03:23 PM   #5
lsmurphy
Registered User
 
Join Date: Aug 2010
Location: Parrottsville
Posts: 296
Time to do some serious maintenance.

All your sensors need to be replaced.

Get rid of your air box.

Drop the cat.

Plugs, wires, caps..........

Go through your electrical.



I'll bet it has been neglected?
lsmurphy is offline   Reply With Quote Quick reply to this message
Unread 06-06-2012, 04:25 PM   #6
buildin1XJ
Web Wheeler
1999 XJ Cherokee 
 
Join Date: Oct 2011
Location: Knoxville, Tn.
Posts: 1,581
X1 on ISMURPHY above do the maintainance and be happy with it. I've done many engine swaps in 4.0s but would not consider the can of worms I would open trying to convert one. If you really want 4.0 buy a new to you Jeep.JMHO.
buildin1XJ is offline   Reply With Quote Quick reply to this message
Unread 06-06-2012, 04:55 PM   #7
Trons
Registered User
2003 TJ Wrangler 
 
Join Date: Jan 2010
Location: Bowling Green KY
Posts: 712
I don't know. I had a friend do the swap but mainly because he got tired of running out of power on hill climbs. He bought the donor vehicle for a good price because it had been wrecked and did most of the swap himself. The only time he needed help was pulling the old one out, putting the new one in and drinking beer.

Having said that, the donor vehicle was necessary. All the sensors, wiring, ect need to be swapped over. Once he got it running, it ran like a champ. He had the AX15 and loved the amount of power it had when coupled to the 4.0. I say, if you got the time, and the donor vehicle, do it.
__________________
'03 TJ Rubicon
'91 Cherokee Laredo, Stock
'98 XJ burned :(
Trons is offline   Reply With Quote Quick reply to this message
Unread 06-06-2012, 05:03 PM   #8
lsmurphy
Registered User
 
Join Date: Aug 2010
Location: Parrottsville
Posts: 296
Yeah I really wasn't trying to discourage you on the face of your swap.......but.......

Donor is the way to go as computer and harness and linkages and mounts......radiator support and radiator........etc.......will all have to be swapped. Drive shafts......etc.


Your 98 must be real special to justify it.


Just don't think you will manage under your $1000 budget.


I'm also going to guess about 30-40 hours of labor to complete.
lsmurphy is offline   Reply With Quote Quick reply to this message
Unread 06-06-2012, 09:16 PM   #9
Pats94
Registered User
2001 XJ Cherokee 
 
Join Date: Mar 2012
Location: Des Moines, Ia
Posts: 421
Find a wreck donor vehicle. Remove the front grill and heater radiator assembly. Try to remove the engine transmission and transfer case as 1 unit. Remove the wiring loom from the donor and replace it plug for plug. Work back forward replace all 4 cylinder parts with all six cylinder parts. Replace all of the ecm's with donor vehicle parts.
I will take time but in the end you will have the truck that you want.
I had a bunch of people telling me I couldn't put a blown 427 in a vega! Lol
__________________
If its stock it sucks and if it scares the hell outta ya its just about right!
Pats94 is offline   Reply With Quote Quick reply to this message
Unread 07-18-2012, 08:16 PM   #10
ZeroGravity
Registered User
1991 YJ Wrangler 
 
Join Date: Jul 2008
Location: Boston, MA
Posts: 3,930
Quote:
Originally Posted by lsmurphy View Post
Time to do some serious maintenance.

All your sensors need to be replaced.

Get rid of your air box.

I don't feel as though the air box restricts the engine enough to justify removing considering it offers very good water protection. I want to remove the "horn" that appears to draw cool air from below.

Drop the cat.

Cat is a new, high flow unit attached a full 2.5" custom downpipe and exhaust that terminates before the rear axle. I have a spark plug anti fouler in the o2 bung which turned my engine light out, what I'm not sure about is whether or not it's going to come back on when I take the cat off. Apparently it's not doing a whole lot but I need it to pass inspection.

Plugs, wires, caps..........

Plugs, wires and etc. need to be replaced.

Go through your electrical.

Electrical is fine.

I'll bet it has been neglected?

Not neglected, abused.
Replies in red.

I'd like to revisit this. The biggest inconvenience would be engine and tranny mounts, are the in the same spots or not?
__________________
91 YJ
98 XJ
2 door love
The U.S. Army vaguely envisioned something bigger than a motorcycle, smaller than a truck, and undaunted by the most difficult terrain.
ZeroGravity is offline   Reply With Quote Quick reply to this message
Unread 07-18-2012, 09:08 PM   #11
ibjeepin95
Web Wheeler
 
ibjeepin95's Avatar
1999 XJ Cherokee 
 
Join Date: Sep 2006
Location: Harrisonburg, VA
Posts: 4,210
4 cyl. XJ's are awesome. You can rev them to the moon. Keep it.
ibjeepin95 is offline   Reply With Quote Quick reply to this message
Unread 07-18-2012, 09:28 PM   #12
ZeroGravity
Registered User
1991 YJ Wrangler 
 
Join Date: Jul 2008
Location: Boston, MA
Posts: 3,930
What does that mean?
__________________
91 YJ
98 XJ
2 door love
The U.S. Army vaguely envisioned something bigger than a motorcycle, smaller than a truck, and undaunted by the most difficult terrain.
ZeroGravity is offline   Reply With Quote Quick reply to this message
Unread 07-19-2012, 05:54 AM   #13
ibjeepin95
Web Wheeler
 
ibjeepin95's Avatar
1999 XJ Cherokee 
 
Join Date: Sep 2006
Location: Harrisonburg, VA
Posts: 4,210
Quote:
Originally Posted by ZeroGravity View Post
What does that mean?
It means just what I said. Those little motors are hard to kill. You can rev on them all day.
ibjeepin95 is offline   Reply With Quote Quick reply to this message
Unread 07-20-2012, 06:35 AM   #14
ZeroGravity
Registered User
1991 YJ Wrangler 
 
Join Date: Jul 2008
Location: Boston, MA
Posts: 3,930
I know what you meant...

Hondas rev real high and are hard to kill too, doesn't get me off thinking about driving one.
__________________
91 YJ
98 XJ
2 door love
The U.S. Army vaguely envisioned something bigger than a motorcycle, smaller than a truck, and undaunted by the most difficult terrain.
ZeroGravity is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.