94XJ2door5speed said:Mechanical is sound save the cracked manifold but a header was on my to do list. I think it is wierd but someone with more experience correct me here. I drained my oil on my 199,388 mile 4.0 and it was still clean. Let me correct this. I bought it with 193,000 mi. I didn't know how it was treaded previosly so i put a junk filter and oil in it for 2 tanks of gas, then changed it with a good filter and good, non synthetic oil. I am a mobil 1, royal purple kinda guy on everything but the age made me stray from my norm. I bought what was on sale, Castrol GTX. I had never ran this but after 4,500mi in the dirt, mud, rocks, highway, etc... visiting the rev limiter frequently off-roading, it looked like new oil and it had not burned any at all nor was it black or discolored in anyway!! for real it was exactly the same as when i poured it in. So is this normal? this leads me to believe that the rings are very very good so i might back it down a bit in the rpm's department before i wreck it.
What do you mean by "junk" filter? It sounds like if the oil is fine then the engine is very healthy for that kind of mileage.