Jeep 4.2L engine

dhermesc

Well-known Member
A friend has a 1987 Jeep Wrangler he's willing to sell me for $2500. Looks really good but has a salvage title. I'm not too worried about the salvage part (don't know if it was wrecked or flooded) he's had it for 10 years. It is burning a lot of oil and it has a mass of vaccuum lines that he he knows some are leaking (they have to after 26 years).

It has about 130K miles on it. What do you think the chances are that it only needs the head pulled and a valve job done? If I did that I planned on replacing the carb and stripping all the emmissions (ei vaccuume lines etc..). Any online "How to" source on this?

Any suggestions on what carb to replace it with?
 
Not to be a jerk, but it sounds like a disaster waiting to happen. The days of the carburetor are LONG past... it"s hard to believe that thing still had one in 1987! I went to Rock Auto"s website and looked it up just to prove it to myself!

(Oh, and did I mention my wife has a 2007 Jeep and I wish she had RUN a few years back rather than buying that darned thing!)
 
I would plan on a complete overhaul. Some of those engines were made by GM & some were Chrysler. I have on of the Chrysler's in my Wrangler & it was about a grand to go through it a few years ago. I would just rebuild the carb it has unless it's one of those half breed fuel injected ones.
 
I believe the 4.2 is a newer version of the old AMC 232-258 style 6 cyl, they started using them in Jeep, when AMC bought Jeep. They were decent engines, but if using a lot of oil, a top end job aint gonna fix it. He wants way too much for it in that condition.
 
I would be more worried about the frame and trans than the engine. The frames rust out and the Puegot(sp?) transmissions were junk. Should be rust free and minor problems for that money. If the frame is solid and the tub is good, probably worth a grand with an oil burner under the hood. A 4.0 will fit where that 4.2 is and be fuel injected to boot. A jeep is always a money pit.
 
They went to TBI injection in the trucks (Dodge and Jeep) in 88 or 89, didn"t put multi-port sequential injection on til 94.

.

A Chevy v6 or v8 swap may be as cost-effective as a rebuild- especially considering the aftermarket support for the electronics and swaps.
 
I pretty much agree with what's been said.
Midwestjeepthing is a friendly website,
most are good people.
jeepforum seems to draw alot of arrogant folks.
As said, if the rest is solid, check close,
an engine swap aint to hard.
2500 is a bit for an oil burner,
unless the rest is near cherry.
Jeep fever is easy to catch, be careful, lol.
Good luck, Danny
 
got a good 92 Jeep Cherokee for sale, $1600. Runs good, just dont need it, in middle Tenn.
 
for what its worth

Can't remember exactly, but I think if you take the 4.0 engine, then get the crank/rods from a 258 and install them on a rebuild, you wind up with a 4.2 stroker motor.
Don't quote me, look it up, but its commonly done...
 
It would fetch 2500 around here (jeep fever) but not from me...
Don't hold me to this (AX15) if it has a AX15 it would be a rare beast the AX15 trans in a 87 is a rare trans in one but you will see one every now and again,,, the AX15 package conversion will fetch a EZ $1000... If it has the P-jo trans plan to spend the grand plus labor to convert it to a AX15 :cry: Then what it cost to replace the input shaft in the transfer case to mate up to the AX15...

A valve job is not goona fix your oil issues but check and make sure the PCV valve is not stopped up... It does stop up on'em and they will leak oil about as fast as you can pour it in...

Carb conversion in one word Webber 38X38 MM DGV...

http://www.redlineweber.com/contactus.html

OK now you are into it 5K and probably needs a engine rebuild,,,, I luv Jeep customers with deep pockets.... They are EZ to work on and a good hobby for someone with the time and money (if you need a $hobby$)....

I get one about once a year they spend 5K are more on it (up-grades) and still have want's its a never ending cycle...

Theirs a group of young boys around here that buy up every $500 Jeep Cherokee around fix them up on the cheap (as cheap as they can) then go out every Saturday day and nite and do their best to tear them up.... I think they enjoy fix'n what they tear up more than playing in the mud with them... I support them with special tools and info as I enjoy seeing them acquire wrenching skills... If I need to know something about a Jeep they know it 8)

Personally if I had to have one I would start out with a EFI engine with a AX15 are a automatic, the auto's are a dime a dozen they rarely give any trouble...
 
Crank and rods from 258 into a 4.0?? UH, let me try to remember from my working for the Jeep dealer- the AMC 232/258 were 4 bearing crank designs while the 4.0 from Kenosha was a 7 bearing crank design, might be a little hard to fit in that crankshaft swap. RN
 
(quoted from post at 12:35:33 05/11/13) Crank and rods from 258 into a 4.0?? UH, let me try to remember from my working for the Jeep dealer- the AMC 232/258 were 4 bearing crank designs while the 4.0 from Kenosha was a 7 bearing crank design, might be a little hard to fit in that crankshaft swap. RN

It never hurts to refresh your memory... the 258 crank is drop-in for the 4.0 block.

Here is a magizine article that covers just what was mentioned, 258 crank and rods in a 4.0. http://www.rockcrawler.com/techreports/stroker40/index.asp

You can also google "258 crank in 4.0" and see its a very common swap done.
 
(quoted from post at 14:35:33 05/11/13) Crank and rods from 258 into a 4.0?? UH, let me try to remember from my working for the Jeep dealer- [b:55239be662]the AMC 232/258 were 4 bearing crank designs [/b:55239be662]while the 4.0 from Kenosha was a 7 bearing crank design, might be a little hard to fit in that crankshaft swap. RN

Don't think so. I had a 1967 Jeep Gladiator pickup with a 232, said 7 main bearings right on the valve cover.
 

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