How much is a engine overhaul on a 1987 Jeep Cherokee?

[Kaycee R]

I just bought a Jeep Cherokee, it has a in-line 6 engine, 4.0 liter

It ran like complete crap the day I drove it away from where I bought it from until I got home dying each time I came up to a stop or started slowing down So I'd put it in neutral and start it back up (it's an automatic) The jeep barley has any power at all to it petal all the way to the ground and it was only going about 65 miles an hour.

I was told the compression might be bad on it, but since then I took out all of the spark plugs and used a wire brush to clean them but them back in and the I started up still sort of misfiring but sounded a little bit better and I test drove it and it had a little more better not dying each time I came to a stop and getting more power not an ample amount but still noticable.

So I was told the compression might be fine and I need to just do a major tune up with it replacing all my filters. and a few other parts.

it sounds like I need to re-hang the exauhst system so that might be somewhere else that I'm loosing power also.

The distributor and rotar are both clean and fine so that's not the problem, I still plan on getting new spark plugs and wires but just not yet because if I don't pass my compression test I need to figure out what I'm going to do from there (overhaul/junk it) unless it needs only something small.

I'm not sure how the catalytic converter is yet I haven't checked.

but any advice on what you've read would be very apreciated.

and if you do know how much an engine overhaul cost please let me know because I need to know that part IF I have to have it done to know whats better to do.

 

[adiabaticfire]

i just recently rebuilt a 4 liter six cause the cam took out a lifter. that would explain most everything you described too. if you start it and it pops and runs crappy take the valve cover off and push down on all the push rods to see if there is a squishy one. if so it took out a lifter and needs rebuilt/ or at least the head removed and the cam/lifter replaced. i cant tell you what a shop charges for a rebuild in the vehicle but think a few thousand maybe. make sure the MAP sensor and all the other vac lines are hooked up right too they suck in that year of 4 liter. good luck

 

[Old Man Dirt]

1. New plug wires.
2. Any exhaust leak before the O2 sensor will mess up the fuel mixture. So look for a broke exhaust header and any other place the exhaust could be leaking.
3. Get the fuel filter and air filter replaced. I would just go ahead and replace the plugs, cap and rotor any way. The plugs could be wrong, and there could be too much of a gap in the cap (or the button could be gone).
4. If it is an automatic then get it serviced.
The AMC engine was a good design and should be long lived. However some times home mechanic's think they know better then the factory and disconnect wires and hoses (vacuum lines) which play heck with the engine management system. When I find this in any used car that I buy, I put it back stock and start from there. That alone has corrected a lot of engine problems for me.

 

[Jay&nigel]

loosing power could be an electrical problem, u checking the exaust system is a good option becuz it can definiately cause the car to loose power, becuz of less compression in the engine chamber. And an overhaul will definiately will be very costly due to the age of the car, just replace it with a second hand motor, if you are trying to save the vehicle to continue use, because the age of the vehicle, its not worth it financially!!..............................good luck!! =)