I HAVE A 1998 FORD EXPLORER, 4.0 DOHC, 108,000 MILES. TODAY WHILE DRIVING I HEARD A LOUD POP, AND THE MOTOR QUIT. IT WILL CRANKS OVER JUST FINE BUT HAS NO COMPRESSION TO START UP. I AM PRETTY SURE ITS THE TIMING CHAIN. I WOULD LIKE TO KNOW HOW MUCH OF A JOB TO FIX THIS AND THE PLACE TO GET PARTS FOR IT. SOME PICTURE OF THE R&R WOULD HELP.

THANKS

 

same think happend to me with my 4.0 shoc, I just replaced the motor that was the best thing to do, looking at engine the passanger side timing chain is between the motor and trans, there is a jack shaft that goes thru the motor that spins that chain. so the only way to change that is to rip out the motor!

 

There are 3 chains, and they run as per the prior post.

1) Crank to a cam blank that runs in the block like the OHV cam.

2) Front of cam blank to driver side cam

3) BACK of cam blank to passenger side cam.

Whoever designed this should be killed.

You have to pull the engine to deal with the rear cam, or even replace the failure prone tensioner.

Leave it to Ford to have the only cam CHAIN system less reliable than a belt.

My '98 has 94,000 on it, so I live in fear of the "Pop" myself.

 

Do a search, there are some posts where the owner did the rear chain in the vehicle. I know it's not much help for a PITA job. I think pulling the engine would be easier. The later engines supposedly do not have this problem, around '04 and newer if you have to replace the engine.