I have seen a lot of explorers with 200K+ miles, what is the typical mileage before they would need a rebuild? I also noticed in one I test drove with 257k miles it had a pretty distinct ticking noise on the top, is there any way to take care of that? adjusting the valves or anything?

id say a well taken care of one should last 200k with matbe some ticking. mines at 122k with no problems at all.

Mines at 149000 and still running very smooth

144k and still gunnin...
-bryan

175K, and still smooth, a little steering pump whine.

219K on a 1992, runs smooth (no valve noise), power seems lacking for 4.56s and 33s compared to my girlfriends dads with 115K with 3.55s and stock tires. His is a sport with a manual though, but mines geared WAY lower (mine would be like 4.10s on stock tires).

200K on a 92. Runs good, lacking a little power in steep long uphill grades.

I have seen the inside of a OHV 4.0L that had synthetic Mobil one in it from day one, visibly NO WEAR inside the engine.

The rocker tips and pushrods are another story.

at 200K miles a OHV needs:
oil pump (good idea)
timing set (great idea)
upper and lower intake gaskets

Then you an get the "refresh" kit from Doug at 4.0performance.com and that sucker will be good to go for another 200K easy.............

Of course stuff like the waterpump, thermostat, plugs, wires, sensors are considered routine maint.

My 91 4.0 had 380,000 miles on the engine when the 2nd transmission went out on the way to trade it in. I still got $5,000 out of the dealer for it!

mine is at 209000 and still runs strong except for a ping with low grade gas so i use 93 and the engine does not ping any more pretty good engine

The only weak (er) points on the 4.0 ohv are the heads (they can/will crack if you overheat the motor bad), lifters (they will tick, normally not until close to 200k). The rest of the motor (other than external things, e.g. water pump etc).

The tranny usually goes way before the motor.

When I took off the heads on our '92 @ 236k, we still had cross hatching on a few cylinders.. (We now have 290k miles)

The OHV motors last a long time with propper care.

~Mark

I just had the 4.0 L OHV on my '92 replaced at 160K miles, and I consider that early. I lost compression in two cylinders from bad rings, but the engine was in good shape other than that.

Just turned 200,000 miles today. Still going strong.

My 93 has 144,000, and the ticking noise has become more noticable in the past year. Other than that it runs fairly well. Still have the original tranny as far as I know.

130k miles on a 97 sohc 4.0

i lost the gears in the tranny.... it was making a grinding sound...
we got the trany out and the fluid was black with little bits of metal in :-) ...
so i have a new tranny now 5r55e

it will last about 220k miles cause the engine still sounds sweet.

134,000 on a 98 sohc 4.0 and it's kicking ass.
although. my belts needs to be changed. and ofcourse mobil one synthetic. stock tranny.

i seen someone with 325k miles on a 95 4.0 splash on ranger power sports. he says it stills chirps third gear.