2005 Jeep TJ Wrangler 4.0L Block Compatibility and Interchangeability

[Toddw]

What 4.0 engine blocks are compatible with my 05 TJ?

 

 

[Moses Ludel]

Hi, Toddw...You do need the later block if replacing a 2005 TJ Wrangler engine or block.  Jordan89oak has lived the experience of swapping a late TJ 4.0L into an earlier model Jeep.  In his case, it went back to compatibility with 4.2L era inline sixes for engine mount bolt hole castings.  Your concern is the other way around, you need the later block (specifically a 1999 WJ Grand Cherokee or 2000-2006 TJ Wrangler block).  This is a useful read, Jordan89oak opens with the frustrating differences between the earlier and later block castings and motor mount methods:

So, the blocks that directly interchange with a later TJ 4.0L like yours would be a 1999-up WJ Grand Cherokee or 2000-2006 TJ Wrangler.  The 2000-2001 XJ Cherokee blocks remain similar to 1999-back, so avoid an XJ Cherokee block for your 2005 model. 

The breakdown of 1991-up 4.0L block interchangeability goes like this:

1)  XJ Cherokee, ZJ Grand Cherokee and YJ or TJ Wrangler (through 1999) 4.0L blocks interchange.

2) 1999 WJ Grand Cherokee 4.0L blocks are similar to the 2000-up TJ and WJ blocks.

[New short block assembly for your application when it was available] 05013161AC 4.0L BLOCK, Short, Contains: Crank,
Rods, Pistons, Rings, Cam
Bearings, Timing Chain, Sprockets
[Remanufactured replacement long block; a fitted block plus the cylinder head] R2640492AA Mopar Reman Long Block
for 1999-04 (WJ Grand Cherokee), 00-06 (TJ Wrangler)

3) Your replacement block must be for a 2000-up TJ Wrangler or 1999-up WJ Grand Cherokee and not any year XJ Cherokee or ZJ Grand Cherokee.

Why?  As jordan89oak shares, the motor mount locations/bolt hole castings and engine driven accessories mounting holes in the block casting change with the 1999 WJ 4.0L and the 2000-up TJ Wrangler.  The 2000/2001 XJ Cherokee block remains similar to 1999-back XJ/YJ/ZJ/TJ 4.0L engines.  The better castings for these older engines are 1996/1997 and up.  The long block engine assemblies for 1991-1999 XJ Cherokees with Mopar EFI/MPI interchange;  2000-2001 XJ Cherokee long blocks are unique (a coil-on-plug head with the '99-back block design);  1987-90 4.0L XJ engines are the Renix EFI design with a different cylinder head and port locations plus provision for a knock sensor, which makes the 1987-90 4.0L Renix long block assemblies different from the 1991-up Mopar MPI design.  

You're only dealing with the cylinder block, but for cylinder head changes, the major change is the coil-on-plug introduction, which begins with the 1999 WJ and the 2000-up XJ Cherokee and TJ Wrangler.

Does that help?  I provided Mopar replacement part numbers to emphasize your block casting group...

Moses