motor swap ?

looks like possibly going ot have to swap another 4.0 into the jeep. wierd though cause its only got 104xxx on the ticker. i was driving it the other day and under accerleratoin it started smoking from the engine compartment. i pulled over and noticed it was blowing oil from the front breather line on the valve cover. the guy i bought it from put one of those cheap ricer oil breather K&N looking things on it instead of running it to the box and it was pushing smoke and oil out . I took the valve cover off and looked to see if there was a screen or something that got clogged on my ccv valve but it looks like there isn't one because its completely coverd by some sort of shield. my gauges didn't act wierd no smoke out of the tailpipe, so i am at a loss. it was pushing tons of smoke out of the breather so i wonder if i cracked a ring or something. i'm going to compression test it tomorrow and maybe that will tell me something.

Soooo, its a 98, if i do need to swap then should i use a motor from a 96 or newer? OBDII i think was 96 is that correct. any info would be great. thanks

ok, update, i put everything back together and started the jeep, pulled one wire at a time and everyone caused idle to go down, except the front cylinder. pulled the plug and it was jet black and wet.i'm gonig to assume this is the dead cylinder, any suggestions would be great as to what else i should check before i turn this thing into an anchor. thanks

You could just swap the bottom end. Front piston is cracked (check down the plug hole for a valve stuck in the piston) You wouldn't be the first one to have a speedo "turned back" by a bad dealership or previous owner. (Some people buy new Jeeps, swap the blocks and trade them back in)

Compression test it, and check again after adding a spoonful of heavy oil to the cylinder (to see if its not a head related problem), it could just be a leaking injector. As for the "blow by" problem w/ oil and did you try and clean all the carbon off the ccv fitting thats plugging it including under the valve cover, inside the ccv fitting (also check the line for leaks) clean out the CCV line and its respective fitting on the manifold. I recently found my fitting to be fine but the line itself was gummed up. If you are talking about unplugging injector wires, and listening for the change, that will indicate a rich running injector.

so if i hear no change then possibly a rich injector? i know the ccv is ok i've pulled it and sprayed parts cleaner clean through it with no blockage. i think i've pinned it down to the front cylinder. but from there i've gone no further.

snacob14 said:

so if i hear no change then possibly a rich injector? i know the ccv is ok i've pulled it and sprayed parts cleaner clean through it with no blockage. i think i've pinned it down to the front cylinder. but from there i've gone no further.

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Head gasket.

Check that hose though and make sure its getting no vaccuum.

Ideally, when an injector is leaking too much gas, and you pull its wires (injector, not spark plug), the engine will not run as rough (in comparion to when you pull the wire of another injector). This is because when you pull the wire gasoline is entering the cylinder even though no gasoline should when the wire isin't connected. A rich (too much gas) condition in 1 cylinder is usually indicated by dry black carbon build up on the plugs. Oil leaking into the cylinder usually leaves oily, tar like deposits.