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how different are the 4.0's

H8PVMT

H8PVMT

NAXJA Member
NAXJA Member
Location
Central Maine
so I swapped in a "new" engine but the guy I bought it from didn't know what the year was, he figured it was a rebuilt 91 but he's not sure, the only clue I have to go on is the oil filter holder is mounted horizontaly and he used a from ph3985....I need to buy a water pump and thermo and see that they are the same for most of the 4.0's, is it the same for all years in the early 90's

thanks

doug
 
I am pretty sure that as long as you get a water pump for a serpentine belt system it will be the same. The serpentine water pumps turn the opposite direction than the older v-belt driven pumps, and the v-belt was never used in an XJ.

[PSA] On another note, just some friendly advice about Fram oil filters. You would be doing yourself a huge favor by not using those. Buy a Bosch, MOPAR, Mobil 1, K&N, WIX, NAPA Silver or NAPA Gold. After reading those on-line oil filter comparisons, I have personally cut several used filters open to check out their build quality. The reports did not lie. Fram filters were by far the most cheaply built filter I'd cut apart. Luckily it was cheap enough that I cut it open unused, and it was no big loss. [/PSA]
 
yeah i am replacing the filter, it was on it when I got it, just trying to use the # to track what year engine.
 
think after 90 they were all the same anyway
Click to expand...
The blocks were basically the same with some minor changes from 87-01
Click to expand...

Nope, not true. Most of the accessory drive, oil filter, and other variuos components are in different locations. I don't have data on the later model XJs, but this is what I dug up and confirmed (via 3 different sources) when I was trying to find a matching block for my 98XJ. Hope this helps.

This Jeep 4.0 L, 242 CID engine is characterized by "Block #665, 535. Head #686". This Jeep engine block was manufactured by AMC in 1987-1990

This Jeep 4.0 L, 242 CID engine is characterized by "Block #405, Head #119, 120. Crank #453. Pilot hole 7/8" deep". This Jeep engine block was manufactured by AMC in 1991-1995

This Jeep 4.0 L, 242 CID engine is characterized by "Block #53020569, Head #0630, Crank #53020767". This Jeep engine block was manufactured by AMC in 1996-1998.
 
Camo-5 said:
Nope, not true. Most of the accessory drive, oil filter, and other variuos components are in different locations. I don't have data on the later model XJs, but this is what I dug up and confirmed (via 3 different sources) when I was trying to find a matching block for my 98XJ. Hope this helps.

This Jeep 4.0 L, 242 CID engine is characterized by "Block #665, 535. Head #686". This Jeep engine block was manufactured by AMC in 1987-1990

This Jeep 4.0 L, 242 CID engine is characterized by "Block #405, Head #119, 120. Crank #453. Pilot hole 7/8" deep". This Jeep engine block was manufactured by AMC in 1991-1995

This Jeep 4.0 L, 242 CID engine is characterized by "Block #53020569, Head #0630, Crank #53020767". This Jeep engine block was manufactured by AMC in 1996-1998.
Click to expand...

Were talking the block only.
More specifically the water pump. Internally \ externally only minor changes occured. The boss for the knock sensor went away, and they changed the oil filter adapter housing. You can swap timing chains\gears, water pumps, pistions, cranks, cams, everything internally.
As i previous stated and will state again, were talking about "BLOCKS". Everything from the head up is a different story.
 
Were talking the block only
Click to expand...

Makes sense. I meant to add that for this specific question (regarding water pump) the statement was correct. Just wanted to throw this info out there.....I didn't mean it as a jab....
 
Even if it's an older motor, he could have bought and installed the newer style horizontal oil filter adapter.

Before installing the water pump, just make sure it's an exact copy of the one that is on the motor before proceeding with your installation. If everything is exactly the same, you're good to go!
 
But the PH3985 is the older metric threaded filter used by the Renix jeeps. It's not hard to rotate the adapter - just pull out the roll pin and hold the adapter in place while you torque the bolt down.
 
I could take a picture but I don't think that will help at all, I took all the accesories from my old engine (96) and put them on it (except h20 pump), when I bought the sensors and t-stat they were for a 96 also and everything worked fine for about 4k, then it started to get hot. When I look online and also !!!1 with a recent post here that the water pumps are all the same, when I check catalogues they saw 87-01 with a 4.0 but we'll see, I'll take a pic in a few hours when I get out of work, what angle would be best?


doug
 
Don't bother everything from 91-01 is going to be the same except the real new stuff has coil packs instead of a distributor. Pre 91s were Renix years and the block didn't change much just had a knock sensor just above the oil pan on the drivers side. The head and intake were different too on those Renix years but you would have noticed that right away. Different TB and intake/exhaust.
 
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