I have a 2001 Sport Trac and the Timing chain Tensioners just went. We tore down the engine to find the remnants of 2 tensioners in the oil pan. We also found the #4 intake rocker laying in the cyl head. What these 2 have in common I don't know. My question is......since the tensioner problem exists for 1999 to 2001 and maybe some 2002's, can I put a 2003 4.0 in my truck? What are the differences if any? My truck has a build date of 9/2000. Two junkyards and a repair facility that I know of have told me that I cannot swap in 2003 and that only a 2001 will work. I find that hard to believe. I really don't care if I need to swap a few items on the motor. I certainly do not want this issue to happen again. Rebuilt motors are not cost effective right now for me.

 

Well that is the easiest question all week,

• tensioner broke,
• chain spun off cam gear,
• cam stopped with valve open,
• piston came up and
• smashed into the valve...
• driving valve up into unmovable object (rocker against cam)
• breaking rocker

 

probably won't swap because of emissions and or a change in mounts or something. I would take a look at the prospective motor myself and see if you can determine the difference. Seems reasonable to me that it should be a swap if no change in body style.

 

Ah................not so easy as one might think. None of the chains jumped time and all sprokets are untouched. Truck ran well but had miss when shut down prior to disassembly. Rocker is in perfect condition, not broke and not a scratch or mar on it.

 

Ah ...So you with held vital information..... not fair.. Now my question, why would you think of swapping engine if there were no collision....?

 

I am at a loss as to what caused the rocker to fall off its perch and what other damage is present that I don't know about. The story goes like this....... I have been hearing a cold start clatter for a month but the wife doesn't drive it much. Last week she went to see her mother and called me to tell me that after she got gas the truck started to miss and the check engine light went on she then noticed the rattle sound coming from under the hood. I drove down and I could clearly hear the sound was coming from the timing chain.Towed it home and rest you know.

 

• Disconnect battery.... (key in pocket)
• pull all plugs,
• perform leak down on all cylinders,(<10%) to verify engine condition,
• if all cylinders test good,
• replace chains and guides,
• reinstall rocker and drive her...

if leak down fails on any cylinder(>15%),

• perform second test wet (tsp oil),
• fail again,
• discontinue test and pull head....

 

Next question................how in the world do you get at the rear chain????????? Engine is out, pan is off and I still dont see the rear chain. Only through the valve cover can I see the chain.

 

having never tackled that job, this is the best I can do..

http://www.google.com/base/a/1610799...58860528658461

 

Ive just been through this with no luck 2002 exp rear guides broke . Rear bottom sprocket is accessable throgh a rubber cover in the center of the motor I replaced all gears chains and guides ran perfect for about 20 miles then brokefront chain and bent a valve put it all back got about 20 miles now passenger cam is not moving my advice is find another motor but if u search here on 4.0 timing chain , youtube, and buy a haynes manual for your car. you also need to rent or borrow the $600.00 set of special tools. I wish u luck.