Help - need advice! Replace timing tensioners only, or chains too? | Ford Explorer Forums - Serious Explorations

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Help - need advice! Replace timing tensioners only, or chains too?

cscmc1

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Year, Model & Trim Level
2001 Sport Trac
Hey friends -- I could really use some advice. I bought a 2001 ST with 150K miles that had a very slight amount of noise that I figured was the timing chain(s). It was not particularly loud, so I hoped that changing out the hydraulic tensioners might alleviate the noise, but it has not.

I pulled the timing cover (what a pain!) and discovered that the main tensioner is destroyed (parts in pan) as is the jackshaft tensioner. Those chains are both somewhat slack, and I can see where they have dug into the metal frames of their respective tensioners. I cannot see the left tensioner, but the chain feels too so I assume it's gone as well. Logic tells me it's time to take it to someone who can R&R the engine and get to the rear one as well.

My question is this: the chains (so far) LOOK ok to me, but I understand that can be deceiving. Would it be terribly foolish to replace only the tensioners, as the none of the local (affordable) garages locally have the timing tool to replace the chains/sprockets as well? Is it even possible to replace only the tensioner on the cam chains? I see the assembly referred to as a "cassette," and am now wondering whether I can even remove just the tensioner.

I would consider a junkyard engine if I weren't so worried about getting a lemon, but even then I would feel compelled to change out the tensioners before installing.

I should add that there ARE very fine metal shavings in my oil pan from the tensioner frame(s) being chewed up a bit by the chains. How tolerant are these engines? Am I asking for bearing failure to try to keep this one in service? Should I just source a lower-mileage 2003+ 4.0 with the balance shaft, change it's tensioners, and install it, hoping for the best? I hate to junk an engine that ran so smoothly, but I do kind of worry about those fine metal shavings.

Sorry for the long post; I very much appreciate any advice you all can offer. I'm kind of in a bind at this point and need to find a cost-effective way to keep my truck on the road. Your expertise and opinions are sincerely appreciated.
 



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If you are referring to the guide and spring tensioner that go on either side of the main or jackshaft chain under the timing cover, I'd just replace those and clean out the pan the best I could since you already changed the other two (hydraulic) and hope for the best. With that kind of milage, why not give it a shot especially since it's apart and you're already considering pulling the engine? This may buy you some time.

Have you pulled the valve covers and looked at the top of the guides?

I have an 02 with a slight rattle when under load between 2000 -2200 RPM. I pulled the valve covers last weekend and found the cam chain guides were still OK so I'm replacing the main tensioner and guide this weekend.
 






Thanks, Bob. I have not pulled the valve covers, but can feel all three chains in front feel slack. I assume then that all their respective tensioners are shot as well (I can SEE that two of them are broken), and that the rear, if not gone, is on it's last legs.

Either way, I'll be pulling the engine (or paying someone to) to try to get things right. I suppose I can check around and see if I can find a 4.0 timing tool set to borrow/rent, and just do the chains, sprockets and all... I just didn't know if I could even get to ONLY the tensioners w/o disturbing timing, and whether that would even be advisable.

Thanks again!
 






Yeah, if you KNOW your cam chain guides are shot, there's not much sense in messing with it. Can you post a pic of what your seeing?
 






Here's the only photo I have handy:



In it, you can just see that the main tensioner is completely shot. The leaves and plastic were in the pan, and the chain has been rubbing into the metal frame of what's left. The chain looks surprisingly healthy, but it certainly could be compromised in ways not visible to the naked eye.

Junkyard 2003+ motor and replace the guides while it's out? That still leaves me wondering whether the guide alone can be replaced on the left and right chains... I don't know whether that's even possible to do w/o pulling the chains and sprockets.

Thank you again!
 






The chain on the lower left is for the balance shaft. I've heard stories of guys running this motor without it with no ill effects. The main tensioner looks like the "old" style which has been updated with 6 leaves and a beefier mounting plate. The other piece (across from the trashed tensioner) is the main (jackshaft) guide and from here it looks OK, but it's only $15.00 for a new one.

Cant really see to well but it looks like the guide for the drivers side cam is still there, but without removingthe valve cover, I'd be hard pressed to say if the hydraulic tensioner is able to do its job since you can't see if it's even making contact.
 






Yes, the driver's side cam chain is there, but I could feel that it was loose (as was the balance shaft chain). I assumed that the tensioner was shot there as well. Can that tensioner be replaced w/o removing the chain and sprockets? I am not at all familiar with timing an engine and worry about getting the timing wrong when reassembling. Furthermore, I don't know whether I'll even have access to the Ford timing tool set w/o buying it.

Thank you, sir!
 






As far as the cam chains and guides, they are replaced in sets known as cassettes and are replaced all together. You need special tools to set the cam timing and in order to do the passengers side, either the engine or transmission must be removed. That's why, before I did anything I pulled the VC's and checked. If my right guide was gone, I would have thrown in a quart of motor honey and driven this thing to the toyota dealer.
 






That's what I figured, and answers my question. So my choice is either buy the cassettes and find a timing tool, and replace all the chains/sprockets/guides/tensioners (and hope the metal shavings from the failed tensioner haven't done other harm to the engine), or buy a 2003+ junkyard motor which should have the revised parts, replace the tensioner(s) I can get to, and hope for the best.

Decisions, decisions!

Thank you again -- it is very much appreciated.
 






As far as the the cam chain tensioners, they are replaceable from the outside. Pretty easy job actually.

Remember, one side of the the chains will usually be a little slack when not running because only one side is being "pulled" on. That's what the tensioner is there for...to take up some of that slack As long as the guides are there and the tesnioners are doing their job, you may be OK .st because it seems loose doesn't necessarily mean it's "bad". In your case, that primary tensioner is lunched and I bet it makes a hell of a racket.

As far asmetal in the oil, that tensioner has been being ground on for a while, so there's not much you can do beyond cleaning the pan and doing a few short interval oil and filter changes.

Of course, this is what I would do personally, others may say to do more, but ultimately it's your wallet.
 






Yessir, that main tensioner is shot, and I can see that the balance shaft tensioner is too. I actually misspoke, and called the cam guide the cam tensioner. I meant to say that I assumed the cam GUIDE can only be replaced with the cam sprockets and chain removed (as a complete cassette). I wanted to just get all that stuff while I'm in there, but I suppose I could pull the valve covers and see what they look like. I would hate to do all this work only to have one of those crap the bed on me a month down the road.

Thank you!
 






To clarify, what I would do based on what you're saying and what I'm seeing:

Replace the primary tensioner and guide, not mess with the balance shaft chain unless that tensioner can be replaced relatively easily.
Button up the front
Remove the valve covers and inspect the cam chain guides, making sure the hydraulic tensioners are making contact.
If all is well inder the V/C's, button everything up, change the oil and drive it.

If the guides are gone/broken etc, then start looking for a motor and probably park it until such a time you can replace it (with all new timing components)
 






That's what my gut is telling me to, BobRob.

Again, thank you!
 






Right20201_zpsecz0mima.jpg


This is what I found under my passenger side VC. You can see the top of the guide is visible on the inboard side of the head interfacing with that pin. If you dont see that, it's not good juju..

Good luck and keep us posted.
 






Will do. I am wondering whether looking for a later (2003/2004) junkyard motor with reasonable miles on it might be the way to go. I'll pull the VC's and see what's under there.
 






I have a buddy who bought a long block at AutoZone for $1500. Not sure how that cost would compare to a JY motor and doing the timing work prior to installing it, but seems pretty reasonable.
 






Good to know. Someone priced a Jasper to me yesterday at ~$3200; yikes!!!
 






OK... I went ahead and pulled my timing cover this weekend. Found the balance shaft chain tensioner was gone, most likely in the pan. The primary tensioner wasn't broken, but it was the old style like yours with three leafs. I replaced the main tensioner with the updated 6 leaf version, the guide, the water pump and HB while I was at it and buttoned it back up. I thought I might still hear the rattle due to the balance chain guide being gone but that was not the case. My engine is whisper quiet through the whole RPM range it was rattling through before. Next weekend, I'm going to drop the pan, and maybe the cradle, if I find I can work that balance chain tensioner, and dropping the cradle isn't too much of a pain in the ass.

The HB was a PITA to get off since I didn't pull the radiator. I had to cut 2" off my HB puller once the bolt was all the way out. The old HB was coming apart so it's a good thing I decided to have it on hand. The new balancer did not come with a new bolt so I smoked down the old one and will replace it as soon as I get a new one.
 






Loads of fun, isn't it? I am looking at a junkyard engine this week. It's from an 03 Explorer flex fuel, but should work, I believe. I'll check all the tensioners while it's out, of course.
 



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It was a bit more of a pain than I expected. I lost 2 hours yesterday running around looking for M8 1.25 90MM bolts for the HB puller. Most places only went to 60mm, but I found an Aubuchon that has them up to 120mm~

Did you end up pulling the valve covers to check the guides?
 






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