Possible timing chain issue

[kspear]

Yestrday my 2004 Explorer started making a rattling noise coming from the front of the engine. It gets a little louder/faster as I acclerate. All my research tells me it is most likely something to do with my timing chain. I've also read that I should start by checkig the timing chain tensioner. Is this something I should attempt on my own? Thoughts/opinions?
Thanks!

 

[drdoom]

Which engine?

 

[kspear]

Which engine?

4.0 V6 SOHC

 

[drdoom]

Timing component servicing is fairly difficult to do on that engine, are you up to pulling the engine out?

 

[kspear]

Timing component servicing is fairly difficult to do on that engine, are you up to pulling the engine out?

No thats a little out of my league! But from what I have read I can get to the tensioner by taking off the front passenger wheel. Just not sure if I should even attempt that because I have no experience working on any timing components/issues.

 

[drdoom]

Well I believe you can take the valve covers off and see if the guides are broken.

 

[Drewmcg]

Its a pretty big job, and generally requires special tools. How many miles on the engine? How many more are you hoping to get?

The left (driver) side secondary (upper) timing chain can be replaced without removing the engine. Same with the primary (lower front) chain. The chains themselves are not the problem (though you should replace at same time due to stretch)--its the guides and tensioners that fail.

Search for Streetrod2000's numerous posts on this. Many other have contributed as well. There's a sticky somewhere.

And be SURE that the right (rear) secondary chain is not rattling before you do anything. If that chain is about to go, then you will need to remove the engine (or trans, but engine is probably better) to replace it. So that might tip the scale against you doing the job, if you're not up for that.

 

[Mbrooks420]

I wouldn’t bother doing it without pulling the motor. If you replace one set, the other set is surely worn, and bound to fail. Better just to replace all related components with the motor on a stand where it is less likely something won’t get messed up

 

[Drewmcg]

I hear you, and that's what I did (twice). But its no picnic getting that engine out and back in, and it doesn't sound like the OP is up to that for sure. But if he's up to an in-truck repair (e.g., left secondary chain, cam sprocket, and guides/tensioners), its conceivable he *might* get another year or two or three out of the truck, depending on mileage, with regular oil change, Motocraft oil filters, and some tlc....

 

[kspear]

It has 155k miles right now. I'd like to get at least another 3 to 5 years out of this truck. The more I think about it, I'm probably better off getting all components replaced. Like Mbrooks420 said, even if I narrow it down to something I can do on my own, another component is bound to fail shortly after. This was kinda my fear al along, just was hoping to avoid a huge repair bill. Thank you all for the input!

 

[imp]

Come to think of it, most repair bills are HUGE nowadays, unless I provide the labor for myself.

imp

 

[kspear]

I've read multiple conflicting posts about new tensioners being primed before installation. I was able to remove the upper and lower tensioners, and ordered a new set. I'm going to replace them before I have any work done to it, hoping its not too late and the casettes are bad. When I got the old ones out, the upper tensioner was able to be easlily depressed, which tells me it is bad. The lower, however, was very stiff and I could not depress it at all. Any thoughts on that or if I need to prime the new ones before I put them in?

 

[Mbrooks420]

You need to prime them.