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#1 09-16-2015 14:48:47

donald
Helper
Registered: 10-05-2008
Posts: 16

89 Jeep Sport w/4.0 engine

I'm looking at an 89 Jeep Sport with the 4.0 engine. Does this engine have any known problems? What should I look for overall?

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09-16-2015 14:48:47

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Re: 89 Jeep Sport w/4.0 engine

#2 09-16-2015 14:54:19

dave
Newbie
Registered: 04-03-2009
Posts: 13

Re: 89 Jeep Sport w/4.0 engine

Donald, mine is a 90 Model, it didn't have any known problems when I got it other than it was filthy.  It has had many unknown problems since then.  One thing after another, we have replaced every sensor known to man, wiring, dist cap, plugs, etc. and it will still miss, sputter pop and run rough most every day for at least the first 15 minutes.  I have even replaced the computer under the dash.

They always said friends don't let friends drive drunk, but I would have to add to that, friends don't let friends drive a Jeep either.  The mileage too is about 10 around town and may 12 or a little more on the road.  I wish you good luck, I have had my first and last one.

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#3 09-21-2015 07:35:30

tim
Newbie
Registered: 10-05-2008
Posts: 9

Re: 89 Jeep Sport w/4.0 engine

Well, the 4.0 engine is considered one of the best engines ever made. They are referred to as bullet proof and can typically go to 300k miles.
But hey, any vehicle that is 20 years old is going to need stuff replaced - they were not designed to last a lifetime.

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#4 09-21-2015 07:38:01

ws_xj
Newbie
Registered: 09-27-2008
Posts: 13

Re: 89 Jeep Sport w/4.0 engine

Isn't the problem with your engine a failure on your part to correctly diagnose the problem? The problem isn't that the engine has required every sensor known to man, but that the original problem has still not been diagnosed properly. Maybe it's time to look at the basics: Air, fuel, and spark. Is it carb or fuel injected?

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09-21-2015 07:38:01

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Re: 89 Jeep Sport w/4.0 engine

#5 09-21-2015 07:40:56

donald
Helper
Registered: 10-05-2008
Posts: 16

Re: 89 Jeep Sport w/4.0 engine

Its been looked at many times, and every answer you could think of has been thrown out here, none of which have cured the problem.

No further discussion is needed, at this point it just isn't worth any more "fixin".

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#6 09-21-2015 07:45:40

evad
Enthusiast
Registered: 10-05-2008
Posts: 240

Re: 89 Jeep Sport w/4.0 engine

Pretty much reliable and inexpensive to operate, but I have only owned this Jeep for about 11 years and do not drive it every day.

Common problems:
Corrosion on wires/terminals
CranKshaft position Sensor
Throttle Position Sensor
EGR system.
RUST
Exhaust Manifold cracking (possible due to a failed front hanger/bracket)

I think most of the other stuff were maintenance items, like brakes, radiator, coolant bottle, U-Joints, Wheel Bearings, etc.

It helps if you have a scanner/reader/tester to determine which sensor might be causing problems.  ;-)


Check out my Jeep XJ

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#7 09-21-2015 07:47:12

adg53xj
Helper
Registered: 01-20-2010
Posts: 20

Re: 89 Jeep Sport w/4.0 engine

other folks have covered the engine. my first thought was the tranny. the auto is the aisin warner aw4 used with all 4.0 cherokees, but the 5sp depends on when in the year it was made: early ones have the peugeot ba 10/5 - not well thought of - but midyear they switched to the aisin ax15, strong and pretty trouble free.

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#8 09-21-2015 07:49:14

jock
Helper
Registered: 10-05-2008
Posts: 30

Re: 89 Jeep Sport w/4.0 engine

I think what you should look for "overall" is how well the previous owner(s) took care of the vehicle. If the thing looks trashed inside and out, the engine is a greasy mess and the oil and coolant look like some kind of toxic waste ...then it really doesn't matter how "good" or "bad" a vehicle is perceived as being; this particular example would not be a wise choice. The inline six has been around (made by Rambler and continued and improved by AMC then Chrysler) since the early 60's. It is designed for longevity, simplicity and durability ...and it fills that niche perfectly. The trouble spot particulars for the older non-H.O. engine and the newer H.O. engine are well documented. But again, you need to look at the big picture.

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#9 09-21-2015 07:49:55

james
Rookie
Registered: 10-05-2008
Posts: 90

Re: 89 Jeep Sport w/4.0 engine

Make sure you check under the rear seat for rust. It's one of the places that seems to rust out the worst. I've seen numerous older XJ's with holes in the floor pan there. Check from underneath the vehicle if you can't look under the rug, you'll be able to see clear as day from underneath if there is a hole there.
The 4.0L is a good engine, even with mileage as long as it hasn't been too abused. Do the usual checks on the motor i.e. does the oil have water in it, color etc, cleanliness of engine compartment, oil leaks etc.
A lot of people that try to clean the engine up to hide oil leaks etc will not bother changing the air filter, check it out and see how dirty or if there is any oil there.
Good luck.

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