I just bought a 98 cherokee 4.0l drove it home got a cel mis fire on 1 i said damn changed all the obvious stuff cap,rotor,wires,and plug. that cleared the cel for bout a day came back up ran it same thing so... i did a compression test and on 1 and 3 showing 90 psi and the rest of the cylinders are 150 so im assuming there "good" so im figuring i need a new cylinder head i know theres a few threads but am i assuming this is my problem?and if so why im in there what else should i change in this process?and are there any company's yawl recommend me getting a remanufactured head from?..I know i could get one pulled off at a junk yard and reworked but would i be spending about the same getting a remanufactured head wouldnt i?i will greatly appreciate the advice.

 

Headgasket
Thermostat gasket
Intake manifold/exhaust manifold
Headstuds

all should run 100-150$

Low compression doesnt necessarily mean a bad head. Rings could be a culprit

 

98s have the better head, whats the milage?? i highly doubt you need a head.do you have oil on the plugs in those 2 cyl.? are you getting excessive blow-by gasses at the valve cover.....a cracked head or bad valve will act differently ,valve you will hear compression escaping into inake or exhaust...the 2 cylinders that are low on compression are not next to each other if it was a cracked head i would think 1+2 would be dead...do more diagnosis before ripping into it

 

Yeah i do need to diagnose a little better i will soon only thing that sucks is its my daily driver and damn if it doesnt take some time to get a head rebuilt around here i will surely look further into it here soon its not actually causing me a problem when im driving it and by no means is it overheating and my oil isnt milky nor is my antifreeze turning brown so we shall see fellas appreciate the advice.

 

And only 117,000 miles on it.

 

if you plan on keeping it for a long time replace the factory freeze plugs with brass ones while you can get to them so easy