• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

junkyard shopping for new 4.0

L

lankchevy

NAXJA Forum User
Location
sw mo
well my engine crapped out on me, so im going to find another 4.0 out of a junkyard to put in it. ive done some searching but want to comfirm everything i *think* ive figured out so far. my understanding is-

*all years of 4.0 short blocks are the same
*the head and injection off my 88 will bolt onto ANY year of 4.0 block
*if i only replace the short block, and keep my head, injection, exhast, ignition,accessorys, and sensors, then i shouldnt have a problem NO MATTER WHAT YEAR of 4.0 short block i get.

just wanted to make sure it doesnt matter what year block i get, im gonna call some yards tommarow if any are open and see if i can find one for a good price.

kolby
 
In general, I believe you are correct. One caveat:

Your '88 has a knock sensor, which screws into a threaded boss on the lower dricver's side of the block. The knock sensor was not used from '91 on. Most of the 90s vintage blocks should still have the boss -- depending on what you read it may or may not be threaded. I'm not sure if the newest blocks still have this boss.
 
hmm well does anyone know if they post 91 blocks will work? i realy need to know cause i have to get a new engine for this thing asap.

kolby
 
I have a 92 with a threaded boss for the knock sensor. I don't know what year they closed this boss up.

When you look for a block, look for the boss. it is near No. 2 clylinder, I think, on the drivers side.
 
First let me say that I've never seen where a knock sensor mounts, so I am not sure what I am looking at, but...

I just looked at my '01 block, and it has a couple of threaded bosses on the drivers side beside the #2 cylinder. One is down low near the top of the oil pan, the other a few inches higher. The upper one looks to me like it would be a pretty decent spot for a knock sensor, but again, I don't know what the factory did.

hope that helps,
Dave

'01 xj
 
i dont know what the used motor cost, but you may want to inquire about a jasper reman. i believe their warranty is 3 years-50,000 miles. sometimes they arent too expensive.
 
jneary said:
i dont know what the used motor cost, but you may want to inquire about a jasper reman. i believe their warranty is 3 years-50,000 miles. sometimes they arent too expensive.
Click to expand...

The jasper complete engine is about $3200 installed with all new hoses, filters, tstat, water pump, sensors, etc. In fact the jasper kit that came with the engine for my wifes oldsmobile had a box of 'parts' that was bigger than the engine on it's pallet. It also included a fram oil filter that of course neither me or the mechanic even considered using :D, it came out of the box and went directly into the 25gallon trash bin, the olds got it's standard Mobil-1 filter... They also have an extended warranty which is nice cause it covers labor as well.
 
lankchevy said:
well my engine crapped out on me, so im going to find another 4.0 out of a junkyard to put in it. ive done some searching but want to comfirm everything i *think* ive figured out so far. my understanding is-

*all years of 4.0 short blocks are the same
*the head and injection off my 88 will bolt onto ANY year of 4.0 block
*if i only replace the short block, and keep my head, injection, exhast, ignition,accessorys, and sensors, then i shouldnt have a problem NO MATTER WHAT YEAR of 4.0 short block i get.

just wanted to make sure it doesnt matter what year block i get, im gonna call some yards tommarow if any are open and see if i can find one for a good price.

kolby
Click to expand...

Any short block will do. even if it doesn't have a threaded boss on the driver's side for the knock sensor, you can have one welded into place.
It would be insane to spend $2000+ on a reconditioned engine. You can build a stroker for less than that.
 
RichP said:
It also included a fram oil filter that of course neither me or the mechanic even considered using :D, it came out of the box and went directly into the 25gallon trash bin, the olds got it's standard Mobil-1 filter...
Click to expand...

Off topic I know but...I spend a lot of time in professional over-the-road garages running drains. Most of them use Fram filters. Thinking they evidently don't find a thing wrong with the filters.

Sarge
 
Sarge said:
Off topic I know but...I spend a lot of time in professional over-the-road garages running drains. Most of them use Fram filters. Thinking they evidently don't find a thing wrong with the filters.

Sarge
Click to expand...

Maybe that the fram truck line is a better grade of filter might have something to do with it, don't know. I've only had two filters blow off in my life, seperated can and base, both were frams. Do a search on 'oil filter study'.
One of my local parts stores just started carrying wix and hastings, has in interesting display of cut open filters from the main manufacturers. I mainly run Mobil-1 or K&N with the occasional Mopar OEM filter thrown in. So far I'm happy with them, we'll see in another 200,000mi if something better comes along...
 
On oil filters, I run a K&N 3001 (PH8A equivalant). This filter has the same fhreads, same diameter, but is twice as long. This way I get double the filter element for the same price. I just need to add about 1/2qt more oil every time. With this and the Mobil 1 oil I only pay about $25 each oil change. Not too bad since I change the oil every 4-5K miles.

Later,
Rough
 
RichP said:
Maybe that the fram truck line is a better grade of filter might have something to do with it, don't know. I've only had two filters blow off in my life, seperated can and base, both were frams. Do a search on 'oil filter study'.
Click to expand...

I thought the same thing but sitting right there on the shelf was the same filter as was in my 1993 Chevy G20 service van and a little ways down was an XJ filter. The garage used XJ's for their parts vehicles.

Seen the studies before. For the most part not done by a professional lab. Meaning in most cases no actual test of flow, leak by, pressure rating, etc. Merely a comparasion of internals.

RichP said:
One of my local parts stores just started carrying wix and hastings, has in interesting display of cut open filters from the main manufacturers. I mainly run Mobil-1 or K&N with the occasional Mopar OEM filter thrown in. So far I'm happy with them, we'll see in another 200,000mi if something better comes along...
Click to expand...

In truth you can find an instance or two of just about every type of filter giving up the ghost on someone somewhere. In bike Emgo is a "bad" word considered super cheap and no good. Yet I've run those oil filters for many thousands of miles with no problems. Personally I try to use Wix as I've seen good test results, plus they are the biggest actual maker for other brands. Personal opinion is most will work fine as long as you maintain a decent change interval.

Sarge
 
One of my '88XJ Limited's has a 1993 HO 4.0L in it . . . I had the complete LONG BLOCK installed (I'm not sure why you are thinking you need to swap heads) . . . it DID (I was told . . . 'didn't personally do the job . . . 'have never looked for it . . . ) have the knock sensor boss. All of the original '88 accessories and the renix system was used . .. . .. . 'works fime, 372,000 miles on that XJ and about 100K miles on that engine (about 70K miles before installation in the '88 and about 30K more miles since installation) (I have three . . . 2 '88 XJ Limited's and a '91 XJ "plain-jane", all AT and 4.0L.) Don
 
hmm i thought i read that after 91 they changed the head and injection system. so i just planed on using my head since there is nothing wrong with it. but if i can use the new one thats great. i cant imagine spending 3000 on a remanufactered engine, unless it was solid gold with ivory inlays. for that price i could do a sbc or 4.3 swap. my unlce just put a new motor in a cherokee a few months ago and found one in a yard for 300, so thats what i will prolly end up doing. thanks for all the replys, u guys are all great.

kolby
 
okay went to the yard today and found a 93 GC with a 4.0, the guy said they can have it pulled by noon tommarow for me, we got my engine out this morning. so can u use the everything off the new engine, exept swap all the old sensors off my motor onto it? or will i have to put my old intake on it? either is fine im just curious. thanks for everyones help on here, you guys are awesome.

kolby
 
It's my understanding that without some machine work (keeping it bolt-together) you need to reuse the non HO head & Renix intake/TB off your old jeep.
 
There's that "head" thing again . . . . guys, I don't believe there's any reason to change the head. Mine wasn't changed (see my earlier post). 'Just trying to help! Don
 
You must log in or register to reply here.

Similar threads

M
Oil pressure question
2
Replies
26
Views
3K
Money_Pit_Incoming
M
cherokeefan_1
2000 4.0 build questions
Replies
5
Views
2K
75SV1
7
K
96 XJ 4.0 LOW COMPRESSION QUESTION
Replies
6
Views
3K
Evan03
E
M
New to my XJ & wrenching - How to choose parts and what to prioritize?!
2
Replies
28
Views
4K
flyin_ryan
F
J
Alternatives to starter kill for aftermarket alarm
Replies
7
Views
979
Vince
Vince
Back
Top