I have on 02 4x4 with 4.0. I was idling down driveway(under 10 mph) and truck just died. No strange noises or pops, just died. I have checked compression in the front cylinder on both sides and have 0 pressure. I am assuming the timing chain gave out. I have the apptitude to pull the engine and fix myself just want assurance I am headed in the right direction. Also, what are the chances that since I was idling and didnt hear any strange noises that I damaged anything(valves,etc...)? Could I be lucky enough for this to just be timing chain and components replacement? I am a maintenence mechanic, I just havent done a lot of engine work

 

There are 2 sets of timing chains in the 4.0l SOHC; one for each bank.
Checking all cylinders' compression might be helpful.
How many miles are on this engine? Had it been rattling?

 

Yes, if you checked #1 and #4 and 0 psi then its a safe bet the gears have slipped, they don't use keyways they are friction fit

While it is an interference engine its not common to get piston strikes in these but it does happen, seen here: https://www.explorerforum.com/forums...ngs-jpg.59331/
0 psi is a BIG slip

Or once you have the engine out and cam out(or movable/timed) you can do a leak down on each cylinder
Or use a borescope to have a look at top of pistons

 

George, engine has about 210k on it and there was no rattling or unusual noise coming from it. Its my daily driver and i drive @ 100 miles daily. She was actually running really good. only used a bout a quart of oil between changes( full syn every 5k)

 

RonD, I have heard it both ways. If chain goes then engine is toast . and some say I should be ok. I just need to know what to look for when I pull the engine .I am not scared of pulling the engine or of any of the work I may need to do. Just not heavily experienced doing engine work so looking for guidance and assurance I am doing right. I really like the little truck and everything else works good. I want to keep it to use on our old farm. I am also confused about which(?) engine I have. Are there 2 different 4.0s? a sohc or an ohv? If there are 2 different engines how do i know which one I have?

 

You've got the later V6~4.0L~SOHC (used in 2001~2011 Rangers & SportTracs)
with those notorious LeftFront+RightRear OilPressurized TimingTensioners.
Your 2002 Engin should have same TopSide fittings as my 2001 Job2 V6~4.0L~SOHC.

 

SO WHEN I PULL THIS ENGINE do i need to leave the tranny attached or should i split them? havent pulled a motor in a very long time. i remember hearing that its best to leave trans attached. any other help or suggestions will be GREATLY appreciated

 

while I have yall here, if it is timing chain issue(gonna replace them anyway if i use this engine) any suggestions on where to get parts and what to get? I figured i would go ahead and replace the oil pump too. what can I expect to spend on parts? would i be better off getting a reman engine?

 

If hoist will handle the weight and you have 3 people then its a bit easier to pull engine and transmission, on a 4x4 you do need to remove transfer case first
Put a piece of plywood over the windshield, I has a snag and engine trans swung back................., new windshield, lol

Remember, when you lift up the engine there will be no weight on front suspension so front of the vehicle will come up very high, which can make it hard to get engine out of engine bay
You can chain the suspension so it doesn't come up as far
Or remove front tires to lower it, after engine is held by hoist

Drain trans fluid first

 

When I pulled my engine to rebuild the cam timing chain system, I pulled the transmission first. I think it is easier and safer to do it that way. Of course, I had a lift available and that makes it easier to pull the transmission.