Will a 6 cylinder from a 2004 Liberty swap into my 2004 TJ?

[Wildman]

Right I’m trying to be cheap haha that’s why I was thinking the liberty but wasn’t thinking it was a v6

Cheap is a relative term. If you could find a WRECKED 2003-04 TJ with a 6 cyl & auto so it was sitting there to take any part you wanted off it might be worth it. But it is always the little things that add up in price.

You could look at swapping in a 4.3 V-6 from a GM vehicle. But again no swap is CHEAP. If you want the cheapest option then trade the current TJ in on a different TJ with a 6 cyl.

 

[Flivver250]

It may be less stressful all the way around to buy the right Jeep and sell hers. Modifying drive trains is not simple, even for an experienced mechanic. Her Jeep if in great condition will sell. Be a good husband and find her a LJR with all the toys. She might just let her hidden freak out.

 

[Codyjensen]

I did nt see it said not have I seen anyone ask but what size tires are you having that 4 banger turn?

They are a 31” tire on it

 

[Hog]

They are a 31” tire on it

Well that is good.. I’ve seen a lot of people ask why their 4cyl won’t get to speed and then find out they have 33” tires...

 

[rouxbicon]

If I remember correctly, a 4-cyl 42RLE TJ has the elusive 4.56 factory gears...which apparently still isn’t enough to turn 31s satisfactorily with that tall OD. If she’s dead set on keeping this particular Jeep, would even deeper gears help? i.e. 5.13?

As expensive as regearing can be, it still could be less expensive and less headache than an engine/tranny swap

 

[Mr. Pink]

If I remember correctly, a 4-cyl 42RLE TJ has the elusive 4.56 factory gears...which apparently still isn’t enough to turn 31s satisfactorily with that tall OD. If she’s dead set on keeping this particular Jeep, would even deeper gears help? i.e. 5.13?

As expensive as regearing can be, it still could be less expensive and less headache than an engine/tranny swap

no TJ from the factory had 4.56 gears 4.10's yes but that was 4cyl manual.

 

[jeepguy03]

They are a 31” tire on it

I'd go back to stock. Even 31's are too much for an automatic 2.4L, this is likely why it only does under 65 on the highway. Stock they came with I believe 225/75R15. 235/75R15 will be slightly larger, but much smaller and lighter than a 31. Even with my 4.0L I notice a small difference in power from stock to 31s.

 

[TJ4Jim]

no TJ from the factory had 4.56 gears 4.10's yes but that was 4cyl manual.

The 4.56 ratio was actually the factory standard ratio with 4 cyl automatic from 03' thru 06'

 

[pagrey]

A 4 cylinder TJ automatic can easily do 65 on the freeway with 31" tires. Something is worn out or out of adjustment. Sure you might take a hit at high elevations or up big hills but 65 should be no problem at all.

 

[Codyjensen]

A 4 cylinder TJ automatic can easily do 65 on the freeway with 31" tires. Something is worn out or out of adjustment. Sure you might take a hit at high elevations or up big hills but 65 should be no problem at all.

You’d think it would but this one won’t. Been trying to figure it out.

 

[pagrey]

You’d think it would but this one won’t. Been trying to figure it out.

I really wish more 4 banger guys would chime in and say this ain't normal so it's not just me, hopefully they will. I might do a compression check, new spark plugs, replace the air filter. Check the short term and long term fuel trims, check the fuel pressure. Check or replace the o2 sensors, check or replace the catalytic converters. Just go to town, cheaper than a new engine or Jeep. I know you've probably done allot of this and I hope you aren't talking about climbing grades or driving at 5000+ ft. In my area a 2.4 really would have no problems unless there was a big grade but I'm close to sea level.

 

[crackedcornish]

just what part of the old Jeep can't your wife part with?

you may have to get a wrecked 6cyl TJ that has a straight frame and swap the tub...you'll get a stronger drivetrain, with the look of the old TJ that she loves

ETA: I'd tell you my 4cyl on 31's has little issue getting to and maintaining 65mph...but mine is a YJ 2.5L/5spd with 4.88's, so apples and oranges

 

[Wildman]

I'm a former 4cyl guy but I had a 5 speed manual and the 2.5 which is a different animal than the 2.4.
Everyone I ever talked with that had the automatic with the 4 cyl HATED it.

Now on that note I never had any issues being able to do 65-70 MPH and I had 33" tires with the stock 4.10 gears and then 4.88 gears. I then went to 35" tires with the 4.88 gears. But again I could do 65-70 MPH except when trying to go over Snoqualmie pass and I would drop down to maybe 55-60 MPH. But I also wasn't scared to rev mine up to 4,500 RPM's and more if needed. I rather enjoyed my 4 cyl and really the only reason I went to the V-8 was because I was going to get a adventure trailer and knew I couldn't tow it with the 4 cyl. Of course plans changed.

 

[JEEPCJTJ]

just what part of the old Jeep can't your wife part with?

That is a good question, I'll add this one:

Who refers to it as "a pos that won’t do 65"?

If it's her, she needs to either sell it or live with it. If it's you, YOU just need a better/stronger/faster Jeep for yourself.

 

[064banger]

2.4 with 31s, manual 3:73. I have zero problems getting to 65mph on the freeway. It will happily cruise at 70 too. 75+ gets dicey though.