So my father informs me that I'm puffing blue on take off, so now I'm lookin for an engine. Are all 4.0s the same as far as the blocks go? I plan on swapping all my parts over if I find a good long block 4.0. Can I use a 4.0 out of any year XJ, ZJ, or WJ?

Thanks in advance,
Redwolf

 

If you're puffing blue just on take off or after sitting at a light, it's likely valve seals. If puffing blue all the time, probably rings. This can vary obviously, but start with a compression test.

 

there are 100's of threads on this subject, you could surf through those as well

 

XJ Cherokee and ZJ Grand Cherokee 4.0L engine blocks interchange.

2000+ TJ Wrangler and WJ Grand Cherokee 4.0L engine blocks interchange.

XJ/ZJ blocks, and the 2000+ TJ/WJ blocks do not interchange without significant modifications. (1991 to 1995 YJ and 1997-1999 4.0L TJ Wrangler blocks will interchange in XJ/ZJ and visa-versa).

TJ/WJ 4.0L Engine blocks underwent clean sheet design changes effective in the 1999 WJ Grand and 2000 TJ Wrangler. These blocks are not interchangeable with XJ/ZJ engine blocks. The reason is motor mount bolt holes and belt driven accessory mounting bolt holes are in different locations, or not present at all, TJ/WJ vs. XJ/ZJ.


XJ: "Regular" (not Grand) Cherokees 84-01
ZJ: Grand Cherokee 93-98 (Gen1)
WJ: Grand Cherokee 99-04 (Gen2)
YJ: Wrangler 87-95 (Gen1)
TJ: Wrangler 97-06 (Gen2)

 

thanks big daddy

 

I'd investigate the cause first before throwing a whole engine away for another. I'd much rather rebuild a tired engine I know than swap it out for an unknown engine.

 

Agreed. Also, seeing as how this question gets asked a lot, I went ahead and made it a sticky in OEM and modified. Thanks Pete

 

Great Idea, Thank You