Well, I realize my 93 Grand Cherokee isn't really part of the question here, but it does have the 4.0L engine.
So far: 386,919 miles. The valve cover's been off twice, once for a bad gasket, once for new rocker-arms to quiet the valve train down. I've replaced all the parts that bolt on the engine at least once, radiator once, exhaust manifold once (with a used one from an XJ), Throttle Position Sensor once, rebuilt the front diff once, rear 4 times!!! (you'd think Dana would get it right eventually!), one time on the transfer case (249) due to a worn shift fork. Rebuilt the front driveshaft once, rear driveshaft twice. Oil-filter adapter O-ring 3 times, harmonic balancer once. The transmission (AW-4) has never had the pan off, but the drain-plug has been replaced twice.
I change the oil every 4000 miles, and every other oil change the fluid in the trans pan gets drained and refilled. I've changed the spark plugs 4 times and the dist. cap & rotor 3 times. Wires twice. Air filter once a year.
If anyone's interested, I've used mostly Chevron Supreme 5/30 or 10/30, depending on the season. And an AC-Delco or Motorcraft FL-1 oil filter. Also, the current rear differential has lasted longer than all the rest with over 100K on it. Shortly after I rebuilt it the last time it developed a very low whine. I started using Lubrication Engineers gear oil on the advice of a friend, and it quieted down and has lasted longer than the rest. I've heard the same thing from other people that use it (not the salesman!)
I drive mostly freeway miles between 75-80 MPH, about 40K/year. Mileage averages about 17 at those speeds but gets up near 21 at 65-70.
I've noticed lately that my oil consumption is up to about a quart/700 miles and I'm blowing some smoke. Also some interesting rattles coming from the bottom-end on start-up but still pulls hard and smooth right up to 4500RPM. I've got another complete engine that I'm putting together and I plan on swapping them in the next few weeks.
I also have two XJ's, an 88 & a 90 that my kids use. No problem with either of those other than the &%&^*& drivers door latch!
Gene
So far: 386,919 miles. The valve cover's been off twice, once for a bad gasket, once for new rocker-arms to quiet the valve train down. I've replaced all the parts that bolt on the engine at least once, radiator once, exhaust manifold once (with a used one from an XJ), Throttle Position Sensor once, rebuilt the front diff once, rear 4 times!!! (you'd think Dana would get it right eventually!), one time on the transfer case (249) due to a worn shift fork. Rebuilt the front driveshaft once, rear driveshaft twice. Oil-filter adapter O-ring 3 times, harmonic balancer once. The transmission (AW-4) has never had the pan off, but the drain-plug has been replaced twice.
I change the oil every 4000 miles, and every other oil change the fluid in the trans pan gets drained and refilled. I've changed the spark plugs 4 times and the dist. cap & rotor 3 times. Wires twice. Air filter once a year.
If anyone's interested, I've used mostly Chevron Supreme 5/30 or 10/30, depending on the season. And an AC-Delco or Motorcraft FL-1 oil filter. Also, the current rear differential has lasted longer than all the rest with over 100K on it. Shortly after I rebuilt it the last time it developed a very low whine. I started using Lubrication Engineers gear oil on the advice of a friend, and it quieted down and has lasted longer than the rest. I've heard the same thing from other people that use it (not the salesman!)
I drive mostly freeway miles between 75-80 MPH, about 40K/year. Mileage averages about 17 at those speeds but gets up near 21 at 65-70.
I've noticed lately that my oil consumption is up to about a quart/700 miles and I'm blowing some smoke. Also some interesting rattles coming from the bottom-end on start-up but still pulls hard and smooth right up to 4500RPM. I've got another complete engine that I'm putting together and I plan on swapping them in the next few weeks.
I also have two XJ's, an 88 & a 90 that my kids use. No problem with either of those other than the &%&^*& drivers door latch!
Gene
arty: 
