1988 4.0 and AW4 compatibility in 1993 XJ 4.0
 

My ‘93 4.0 HO drops oil pressure at hot idle. Gauge was reading 5-10 pounds. Confirmed gauge readings with mechanical gauge. Found an 88 Engine and AW4 assembly with 106k for $450. Would this be compatible in my ‘93? I appreciate it fellas

The 88 is the Renix era engine so the sensors are all different, but I believe you can swap everything from the 93 over to the 88 block. Are you swapping engines just because your oil pressure is low at idle? Do you have any other symptoms of the engine being bad?

Slight backstory, when I bought my '93 the previous owner has busted the 6th cylinder piston, so my dad and I went to a junkyard pulled an engine out of an 01. Got home and found out the head was cracked. Fortunately, I had a head off an '89 and put everything together. The engine has never had good oil pressure. I don't necessarily think its a bad engine but it does drop at to 5-10 pounds at idle. Has about 35 pounds at 60 MPH. Also has upper engine noise. Instead of getting it rebuilt for $1750 I'd rather just buy another engine. Would the AW4 work? I know the splines are different but is it possible to swap?

The splines in the transfer case may be different but you can swap the input shafts in them.

Thats what I was thinking but I just didn't know for sure. So if I swap all the sensors everything should work?

Yes and you may have to use the 93 intake manifold and throttle body also. I am not very familiar with the 90 and older 4.0s.

I appreciate all the info man, just didn't wanna buy something I couldn't use. Thanks again

Do you NEED to use the trans?

I have a writeup for swapping an HO motor into a Renix. You can use it as a guide going the other direction.

Here's a link: http://cruiser54.com/?p=100

Well my AW4 in my '93 has 290k on it and the guy Im buying the engine from is selling the assembly as a whole so technically no I don't need it but the AW4 I'm purchasing has a lot less miles

That link is much appreciated, thanks!

I wouldn't worry about your trans. Just use it and sell the other one that comes with the engine.