1988 Comanche Pioneer

[BlueXJ]

I HAVE AN 89 BONE STOCK WITH THE 4.0L BUT IF IT GOES BAD IN THE NEAR FUTURE i AM GOING WITH EITHER THE 5 CYLINDER mb DIESEL OR THE CUMMIN 4bt

[rentakid94]

well guys its looking like im going with a motor swap sooner than expected. 2 days ago i took my comanche for a short road trip (about 100 miles) when i got back i ran over to my farm and hit a little mud pit (wasnt beating it at all) and went down my driveway and started to head back towards my buddies house. about 2 miles down the road my jeep started increasing in rpm's from its idle whenever i would push the clutch in. it normally idles around 700 rpm. it took itself up to 3000 rpm's and would not drop at all. i got it to the local gas station and popped the hood. it was seeping oil out of the valve cover gasket. yesterday i pulled the line off the top of the valve cover and off of the other thing that line hooks into to find a white milky mixture (oil and coolant). i fired up the jeep and it idles normal for a few minutes until it warms up. then it does the same thing. increases in rpm's till it hits 3000 rpm's. im leaning towards a cracked head but i am not sure. it has about 187,000 miles on it. any help would be great guys as this is my daily driver right now