before instailing a used 4.0 engine,, what should be done?

[Isaac]

Hi,, i have a 92XLT 4x4 4 door,,
the engine is not well to say the least,, the "tapping" is turning into sounding like a "knocking" and getting worse,,
oilpressure is getting worse,lossing power and acting like it's only running on 5 cylinders,, very poor fuel miledge.
im going to do a little more testing before i decied to replace the engine (compressoin testing ect.)
anyway,, i have found a 94 4.0 longblock in excelent running order with only 71K mils on it, my ? is,, what do you guys think i should do to this motor before i drop it in?
other then normal stuff,, (hoses termostat ect.)
maybe throw an oil pump and pickup screen in while it's out? any other ideas?
thanx in advance for any help!
Isaac

 

[DOGMAN]

It would be prudent to explore other rememdies for the problems you are having with your X before pulling the motor. However .........

If you do decide to replace the motor, I wouldn't go to all the trouble to pull the motor and replace it with one that has 71K miles on it, even if it was running fine. If it was me, I'd either rebuild the one you have (preferable), or go through the 94 with 71K on it before you drop it in. But that's just me. You just might get many good miles from the 94 71K mile motor without doing anything to it, but if it was me, I'd go through it.

How much are you paying for the 94 longblock? Where are you getting it from? Do you know it's history? Are you doing the install yourself, or having someone else do it?

 

[Rick]

74k is low mileage for a 4.0 OHV. Only about 10k per year. If that is the true mileage I would leave it alone and just drop it in. I have 140k on mine and it doesn't use any oil and runs great.

 

[Isaac]

maybe i didnt make myself clear,,,,,,,,

ok like i said Dogman,
i have some more testing to do to the engine currently in it,,
the 94 longblock is $500 bucks,, which is a very good price,
yes it is origanal mils, as far as pulling the old out to put one in with 71k,,
the engine that is in the explorer now has 144k on it,, which is MORE THEN Double the miledge on the 94 4.0.
and as stated before,, it is in (Excelent running order with warrenty!)
and yes i would be doing the instail myself.
ill repeat the ? as stated before :
" whatshould i do to the motor before intailing?"
im thinking ill probably throw a new oilpump and pickup screen in.
of course i will be cleaning the engine very heavely.

Rick :
yes it is very low mils,, like i said the one i have in it now has 144k on it and it was not mantaned what so ever, oil never got changed (due to preveous owners)
and it was not kept up, but still it has 144k on it.
71k is just barly breaking a colgone in.
Thanx for any info given.
Isaac

 

[JDraper]

New oil pump most definitely. That's cheap insurance. Other than replacing that, I'd just give it a thorough checkover. Ya might wanna do a thorough compression check to make sure you don't have any major problems like blown head gaskets, warped heads or cracked heads.