If your 4.0 SOHC timing chain rattles...

[Dean Hedin]

If your chain only rattles on start-up and then goes away once it warms up...



Then you should change the tensioners as described in the link (watch parts one and two)



One thing the presenter fails to mention is that you must pump up the new tensioners with oil

before installing them. Place them in a dish of oil and keep cycling them until it becomes hard to push the plunger.



The rear is easy to install but the front is more of a challenge.



Mine started rattling over the winter (2003 with 105k). Replaced yesterday and all is good. I used the aftermarket tensioners on ebay (about $17 each) Motorcraft ones are about $80 set.



If your chain rattle does not go away after warm-up I would still attempt this solution, but I would have less expectation of a remedy.



Apparently these need to be changed every 75k miles.

 

[Ed Fenwick]

Good instruction Dean. Do you know why the tentioner won't get primed while driving? I have a 2002, is the top (front tentioner) under the thermostat also? I guess that I will buy two new ones and try again. Right now, I hold the throttle to the floor for 5 seconds to get oil pressure and then lift the throttle to start.

Ed

 

[Todd Z]

Yes sir...



Todd Z

 

[Dean Hedin]

Well Ed, my only addition is to mention priming the tensioners before installing them. That is someone else who posted the youtube videos.



I tried your "crank before start" and I like it. Definitely gets rid of the initial growl at start.

Sound advice, especially if the truck had been sitting a while.



I think that, in the end, this is just a symptom of the wear on the guides and eventually the worse will come. But from where I am at presently that won't be for a least another few years.