Hello and a Service Interval Engine Question
 

Hi There. My name is Chris and I recently got back a 2000 Ranger 4.0L V6 XLT 4WD automatic transmission that I had given to my mom about 10 years ago. I love the forum and appreciate all the advice people share. When I gave it to her it had about 125,000 miles on it and now it has 160,000. I have never fixed my own cars or done any work myself but am pretty handy and thought it would be cool to learn. Plus this seemed like a great truck to start with. This is what I have completed on it so far.
1- Brakes: Replaced front pads and Rotors and Rear drums/pads and flushed brake fluid
2- Put in a new transmission pan (with drain) and did a put in a new filter and changed about 30-40% of the fluid in the process
3- New headlights and Radio
4- Oil and Filter change
5- New Serp belt
6- New plugs and cables
7- Rear and Front Diff as well as transfer case fluid change
8- Fixed a vacuum leak that was throwing a lean code.
9- Changed brake pedal sensor

So she runs great......generally transmission seems to be fine. So the question is...........it has 160,000 on it and it seems like there are a few places where it is starting to leak a small bit of oil.....few drops here and there. (what seem to be the major seal points of the engine). It is also seems to be using a little coolant....not much. I drive it a lot and I would say I have to top it off once a month (overfill compartment) and it seems a little dirty.....not milky but more dirty. Oil changes have been fine and oil looks fine with no coolant in it. Now I want to replace all the hoses and do a proper flush......but wanted to see about what engine overhaul or maintenance I should be looking at. I know there is probably a mindset of "just keep driving it if nothing major" but I have grown to love this little truck and enjoy working on it. I have looked at some videos and read posts about timing chain, head gasket etc......and am looking for some guidance about is it time to pull the engine and see to it all at once? Is this prudent? Or is it a 200,000 mile engine that I should just leave alone?? Body is in good shape....very little rust and paint is OK. I appreciate the guidance and look forward to the responses. Thanks again for the cool forum. Chris