I know it needs to be done but I have over 100,000 miles and I know its not covered anymore on my 2000. Has anyone done this themselves? What is involved? Is it something a moderately experienced wrencher can do?

 

my DVD manual shows the hydraulic tensioner as part number 303-571 (T97T-6K254-A)

But that part looks like it just unscrews from the side of the engine, it can't be that easy.

 

Might be pull the engine time for the back passenger side one.

Are yours noisy? Clattering? Running poorly, as in going in and out of "tune" at idle?

Did Ford ever do anything to them under warranty?

Maybe just pull the front one and assess it's condition, then plan accordingly.

 

It is definitely the front passenger side. I do not know if ford did anything prior to my purchase. I bought it with 80K on it and its just now starting to clatter. It does idle poorly sometimes, but I'm also getting lean bank codes so I'm trying to track that down. I've cleaned the AIH and MAF, replaced the PCV and cleared the codes, but it just came back yesterday.

So is the tensioner part the one I am showing, because the DVD manual shows that procedure as just unscrewing it and screwing a new one in. I didn't think it was that easy. Is it the chain guides that clatter so you have to get to the main timing chain or is it the tensioner I'm showing that makes the noise?

 

I did it. My noise was the front cam chain tensioner on the driver's side and the main timing chain tensioner (goes from the crank to the jackshaft). If you need to change just the tensioner on the passenger side you can access that one from the wheelwell. It looks like a big nut on the side of the head towards the back. You only have to remove the engine if you need to change out the passenger side cam chain guide (aka cassette) which is on the back. In my case the chains were fine. I did the work with 142k on the motor (2000 explorer). Runs better than new.

To do the driver's side tensioner you need to remove the upper and lower intake. The kit comes with an updated tensioner along with upper and lower intake o-rings, an oil restrictor (about the size of a pencil), and a new threaded pipe plug. As for the main timing chain, I replaced the tensioner and guide which requires removing all accessories, the water pump, and obviously the timing cover. You will need a puller to remove the balancer and a new balancer bolt when you do the reinstall. As for removing the accessories, I left them on the brackets and just unbolted the brackets after disconnecting the alternator and disconnecting the lines going to the ac compressor and power steering pump.

If you tackle this you may as well replace all your hoses, buy a NEW water pump, new serpentine belt, new fan blade if you see cracks, new fan clutch, new idler pulleys if they rattle, and new thermostat. It's not hard, just give yourself plenty of time to do it, if possible. I did mine over the course of about three weeks which gave me time to review my work along the way. Fortunately during this time I had my trusty 94 F-150 to fall back on while the explorer was down.

 

The lean codes could be the intake manifold gaskets/o-rings, those are always an issue on these.

 

Thanks for the responses. I'm pretty sure at this point I need to do the upper and lower manifold o rings in order to nail down the lean codes. I have sprayed carp cleaner around the intake but I don't find any indications of leaks. It could be the MAF sensor, I'm going to have to get in and drive around a while and do some live tests on the sensors to see if I can determine if it is a sensor or vacuum leaks. As far as the tensioners are concerned Geo, I have some specific questions before I tackle this. I'm totally fine pulling the timing cover off and replacing parts. But before I do it I want to understand what I am replacing. Is there a way to tell the difference in noises? Can I determine where I should start by where noises are coming from? How did you know yours was the drivers side and the main timing chain? Should I just start by replacing the passanger side tensioner that I can get to and see if that does the trick for now? It sounds like if the main chain is ok then you can replace the tensioners without removing the chain which would require new timing and that seems to require quite a bit of experience and special tools. And Geo, can you give part numbers for the kits you are talking about? Thanks I really appreciate it.

 

Ok so the LH hydraulic tensioner doesn't look bad, remove upper intake manifold and then:

and add the new oil volume reduction plug supplied with hydraulic tensioner


and I can replace the manifold o rings which may solve my lean code problems.

 

The main timing chain rattles under load between 2000-3000 rpm usually when cold. It could sound like anywhere from slight detonation to a bucket of marbles. Normally it goes away once the engine warms up but as the miles accumulate it takes longer for the noise to go away. As for the cam chain tensioner, the engine would sound like a powerstroke diesel sometimes when either idling cold but usually after restarting hot when it's been running awhile. It was pretty obvious where the noise was coming from just listening to it idle with the hood up. Also note that the front tensioners are more prone to failure than the rear. As for chain replacement you could replace the main chain without too much difficulty. It's the cam chains that are a pain because then you need use a timing tool.

 

its definitely from the front and its only at idle. It seems to go away when the rpms come up. So three chains right? one camshaft chain both right and left and those are the RH and LH cam chain hydraulic tensioners? Then there is the main timing chain and that has its own tensioner. So if it sounds like its coming from passenger side at idle but goes away at higher RPM it may be the lower RH cam chain tensioner.

 

I would start with the front and see what happens. If your Explorer is 4wd then you will see the balance shaft chain also. May as well replace the guide for that chain also since you are in there even though it's not prone to being a problem. One issue I had replacing the tensioner on the top left was that the sensors screwed into the plastic thermostat housing were in the way. Its easier to just remove the three bolts holding the housing and remove it instead of trying to remove each sensor and potentially cracking it. When you go back to install it just put plenty of silicone on the bottom before you bolt it back down. Also remember that next to the tensioner is a pipe plug that needs to be removed in order to install the oil restrictor in that passage. I think it takes a torx #30 to remove it. The kit will come with a new plug. On the main chain replace the tensioner and guide.

 

you are saying that since I have a 4wd when I go to replace the cam chain tensioner on the upper left when I remove the intake manifold I will have access to the balance shaft chain tensioner? I did not see that in any diagrams, I will go back and look. Also if replacing the cam tensioners doesn't take care of the problem and I need to pull the main chain cover that I should just replace the chain tensioner and chain guide? Are you saying you did not replace the chain or jackshaft gears so you didn't need to do the cam timing? I read yesterday where people were buying a kit that included the chain, new sprockets, the main guide and tensioner but once you remove the jacksproket you have to retime everything and that looks like its pretty difficult.

 

First if you want your chain tensioners and lash adjusters to last then change your oil with GOOD oil and change it a lot more often than ford recommends. I'm not even going to get into brands of oil but quick lube oil changes at extended intervals just kill these things. Ive rebuilt dozens of these engines and the internals on all of them were so sludged up it was amazing they even ran. Just a tiny bit of sludge screwes up all of the hydraulicly operated parts.

Second, if you tacke a chain job yourself I highly recommend getting the proper tools. OTC makes them and most tool trucks can get them from OTC. It's a major Pain in the butt with the engine in the truck but it's doable. I always just pulled the motor myself. It was much faster in the shop that way.

 

The balance shaft sprocket and chain are behind the timing cover. In my case I did not replace the main chain and sprocket because they looked brand new. Besides, after installing the new guide and tensioner the chain was tight so I knew there was minimal stretch even after 140k+ miles. I have also always used synthetic oil which I think helps. Your case may be different. If you do decide to replace the sprockets and chain note that the kit does not come with either the guide and/or tensioner. I would consider going to directfordparts.com to get what you need. If you want I can get you the specific part numbers if you don't have them already.

 

I ordered yesterday:

YL2Z9E472AA- Intake manifold kit, which includes upper and lower intake manifold gaskets (I'm told) new O rings and the LH cam chain tensioner and oil restrictor

E7RY6A340B- Harmonic Balancer, pully, Bolt
YL2Z6L266AA- Jack Shaft Chain Tensioner
2L2Z6K297AA- Crank to Jackshaft chain guide
F77Z6020AB- Timing Cover Gasket
E6TZ6700A- Front Cover Seal

I'm hoping my Jackshaft Chain and sprockets are in good shape. I don't want to attempt the cam timing or buy the tools, so I'll keep my fingers crossed. They wanted to sell me a new Crankshaft Pully and new sensor. I guess those parts were upgraded with a TSB at some point, but I didn't go for those parts that would have been another $150. Its running good now except for the lean codes and chain noise so I didn't see any reason to change those out. Plus I think the only reason they changed that was the problems with the CPS, which it looks like the same CPS I have on my F350 diesel. And I did find out the manifold gaskets and the LH tensioner were done by the previous owner in June of 2001. It was throwing the same lean codes 171 and 174. So I figured since I'm going to have the manifolds off I might as well replace the cam chain tensioner again. Anyway, I'll dig in to this probably next weekend and let you guys know how it goes. There was a killer thread on another site that went through 12 pages of experiences with this procedure and the timing of the cams if anyone is interested PM me and I'll send you the link. Lot's of good pics and info.