4.6L Explorer engine timing chain ooops!

Got a local customer with an Explorer who came to the shop with a noise coming from the front cover. As I suspected the timing chain guide on the pass side was broken completely and both movable guides were worn through, right down to the tensioner. Attached is some pics.....

 

[Pontisteve]

I own the 4v cam timing tool kit, and have done this job before. Here's a little boots on the ground info for you.

The chains rarely ever go bad. The guides and tensioners do. On the 4v, we replace the newer style phenolic tensioners with the older style cast iron ones, with the ratcheting ladder. They fail MUCH less. I think Cloyes carries those cast iron tensioners. I'm not 100% sure if they're the same for 2v engines like the Explorer, but if they are the same, try to acquire the cast iron tensioners.

The chains rarely go bad. Unless they have been loose and hitting the timing cover, I wouldn't sweat re-using the chains. However, they could stretch over many miles. I'm not against replacing them. Ford uses Morse chains, which are very good.

The tensioner arm and guide are what often break or wear out. These should be replaced every time you're in there, along with the tensioners. These six pieces are the weak links.

Personally, I think there is a connection between using regular oil and the guides/tensioner arms failing (by wearing out the nylon). Motorcraft oil in the lighter weights is semi-synthetic. If you look at the ratings on the oil versus other brands, you'll discover that Motorcraft oil is rated the same as full synthetic, where all other brands of non-synthetic oil are not rated as high.

In short, Motorcraft makes killer oil, and air/fuel/oil filters. Their stuff is very good. I use the Motorcraft 5w20 in my 4.6L explorer, and it has 156k with no signs of trouble yet. I believe that most people use whatever brand of 5w20 they like, other than Motorcraft, and I think that causes the nylon guides to wear prematurely. As these things wear, they can cause the tensioners to be ground down by the chains too.

The 2v valve spring compressor tool is the same one used on the exhaust valve of the 4v engines. The 4v intake valve compressor is unique. Explorers had 2v engines, but Aviators and Cobras had 4v engines. If you're doing this job just one time, I would watch the above referenced video on youtube, and learn how to use a flathead screwdriver to pop off the rocker arms. I've done it before, and it actually worked great on a 4v engine. With a little care, you can take all the rockers off.

You don't have to worry about rotating the engine and bending valves if all the rocker arms are off, because all the valves are closed. If you don't want to buy the OTC 2v cam timing tool kit (around $100), then do yourself a favor and set the engine at TDC on the compression stroke before tearing it down at all. In this scenario, you could just remove the chains and put the new parts on without needing the tool kit to re-align the cams.

The 2v cam holding tool is a bridge that goes from one side of the head to the other, and holds the cam in the middle. This keeps the cam from turning due to valve spring pressure. Guys have done this before with vice grips too. Just gotta get the vice grips to be touching the head so the cam doesn't move.

Since you can buy the cam timing tool kit for around $100, you could just buy it, use it, and then sell it to the next guy on here who needs to do the job for a bit less than you paid.

The crank holding tool basically just lines the crank up to something like 11:00 position. This is a safe spot that puts all the pistons down in the hole a little bit, preventing any possible piston to valve contact. You could duplicate this crank position by looking at pictures.

The cam holding tool is about the only important one, as it holds the cam from moving under valve spring pressure. But if you remove all the rocker arms, there is no pressure.

Personally, I don't think the cam gears need replacing very often. Not unless its really high mileage or something. They are hardened for a few thousands of an inch into the surface. Below that, they are soft. Unless you have somehow physically damaged one, they are generally pretty reusable.

Make sure the guide pins are in good shape. That one or two pins that the guides pivot on can break off or fall out or something, and take a motor out. I've seen them fail, but only in racing.

 

[drdoom]

I am still a bit confused, but have found a 2V camshaft holding tool @ Summit, and have tried calling tech but haven't gotten through yet. Pontisteve & Number4 would that work? This is the tool Mike from 1Aauto uses in his vid. Thanks guys for the help, I really appreciate it.
Number4 thanks very much for your gracious offer, but I live in VA.
EDIT: I spoke with Summit this morning and they are sending over the OTC 6477 holding tool.

 

[Sedition]

Can easily drop oil pan with engine in vehicle..

Just a quick note for anyone looking. Yes you can and MUST drop the oil pan on the 4.6L SOHC V8 Explorer when doing the timing chains. You just have to lower the anti-sway bar (not completely remove it) loosen off the tie-rods (not completely remove them) then drop the front diff housing by undoing it's three mounting bolts only. It takes me under an hr to drop the pan, using a car lift and impact weapons, lol.
us::exp::

The gasket will be fine to just Ultra-RTV

The bottom of the pan will be loaded with crud!:roll:

 

[Pontisteve]

The OTC 6487 is the whole kit for 2v motors. Check it out. It has a few different tools I'm not used to seeing in the 4v engines, so maybe I'm missing something. Usually the cam holding tool is the most important, unless you're timing the cams from scratch.

 

[Number4]

All that's needed for the 4.6 is the two items are the far right which span the head and the two at the far left which go into the cam.

I was of the impression that this went at the front of the engine, but in another thread here, I saw them in place at the back.

When I contacted OTC, they said these did not fit the Explorer 4.6 2002-2004.
I didn't even check fitment at the back of the head.

 

[Number4]

[MENTION=89008]Pontisteve[/MENTION], can you veryify placement?

Also, [MENTION=75839]drdoom[/MENTION], did you get OTC 6024?

 

[Sedition]

I find that the cams are easy enough to line up with hand tools. If you leave the cam sprockets on and cable tie a 19mm wrench somewhere around the intake they won't move. Also the way it's timed is actually quite simple. Crank dot at the bottom and each cam dot exactly 30 links away from the crank dot.

 

[Sedition]

It's 30 links both ways and the sprockets are keyed, impossible to be out by a fraction of a degree. Allthough If I was going to set the cams with say 4* of advancement I'd most certainly use degreeing equipment.

 

[CDW6212R]

It's 30 links both ways and the sprockets are keyed, impossible to be out by a fraction of a degree. Allthough If I was going to set the cams with say 4* of advancement I'd most certainly use degreeing equipment.

I am sorry and was wrong for my comments if those timing marks are "keyed" and intended for timing like older pushrod engines. I grew up with the normal(old) simple timing methods, lining up two dots. But some of the newer engines seem to be infinitely variable, requiring special tools to solidly lock down the timing components.

I don't know anything about timing the modular Fords, I've never dug into one before. Regards,

 

[Pontisteve]

I haven't done the 2v Fords, or Explorers specifically. I assumed they were the same as the 4v, minus the extra cams, but that is an assumption when it comes to fine details.

I can tell you that the chains have copper links on each end. If you fold the chain in half, each end would have a copper link. The link darkens with age and is harder to identify, but it's still there. Instead, most mechanics just clean the chain in the parts cleaner, dry, then mark each end link with white paint. There would be an equal amount of links on each side of the chain, and an equal amount of links to the timing gears. The crank dot goes straight up. The cam dots line up with the links on the chain.

When you're looking at it fully assembled, you'll notice that the two cam dots are not perfectly lined straight "up", and are not perfectly symmetrical either. As I recall, the passenger gear is pretty close to straight, but the drivers cam gear looks like it's clocked differently.

More important than the cam tools I think are the basic concepts...

1) You cannot bend valves if the rockers are off.2
2) The short block needs to have the crank turned to the safe spot, around 10:30. This should line the dot straight up.
3) The dots on the crank and cam gears need to line up with the dots on the chains.
4) The dots on the chains can be anywhere really. Just grab the chain, fold it so that both halves are evenly distributed, and paint a dot on each end link, top and bottom. The factory did the same thing, just with a copper link.
5) One chain sits behind the other, and therefore needs to be taken off last, and put back on first.
6) The chain tensioners need to be slowly compressed in a vice, using some sort of soft jaws. SLOWLY. Then stick a little allen wrench in it to hold it compressed. Ladder types have to have the ladder released while compressing.

 

[Silver_Shadow]

I keep reading "Don't move the crank or cams with the chain not in place." I'm sure it is the best advice. But...my son thought he was "helping" and while I was away took the chains off. Ok, no big deal, if nothing moves...except, when he took the chains off, he slid the gear off the crank, and in the process, pulled on the chain and rotated the cams, both to differing degrees.

Engine is a 4.6L 2v Romeo. Crank key is in the 12 o'clock position (up) right cam has the timing dot just about in line with the valve cover mounting surface (to the inside) and the left cam has the timing dot just about in line with the valve cover mounting surface (to the outside).

Pics below.

So now I'm stuck as to what to do. Haynes says on the 4.6 Romeo, the keyway on both cams (yellow line in pics) should be perpendicular (90 degrees up) to the mounting surface at TDC (which is not 12 o'clock on the crank. closer to 10:30/11 is what I gather).

 

[Pontisteve]

It's no big deal. Even if the cams rotated fast under spring tension, I doubt there would be enough energy behind that to bend a valve.

You will of course have to re-time everything. There is a cam timing tool kit that OTC makes for about $100 that gives you all the factory tools. But in the end, all you're doing is lining up the dots. The tools can be nice, but not entirely necessary. Here's what I would do.

Remove both valve covers and remove all roller followers. Keep them in order. There is a 2v tool for doing this, but you can google a video of how to do it with a flathead screwdriver that works pretty slick too. I have it on my computer somewhere.

With the rockers removed, all valves are closed and there is no possibility of hitting anything, so you can rotate the motor and the cams freely. With no valves open, there is no spring pressure, so everything moves easily as well. And nothing tries to spring out of place.

Each chain has a dark copper link in two places, opposite each other. You can use these copper links as guides, or you can simply fold the chain in half, and mark the link on each end with white paint. The copper links are nothing special, they just represent opposite ends of the chain.

Turn the crank keyway to about 10:30 position. That should be close. Now put the chain on the side which is furthest to the back on the crank gears (which I believe is the driver's side, as I recall). Line up the dots on the cam gears with the painted or copper marks on the chains.

The tensionsers should be compressed slowly in a vice, and once compressed, a small allen wrench or pin is inserted into the hole to keep them compressed. Once you have the dots lined up, pull the pin on the tensions and everything will pop into tension.

Once all the dots line up with all the copper or painted chain links, and both tensioners are released (tensioned), you should be good to go. Reinstall rocker arms on all the closed valves (cam lobe pointing away from rocker arm), and you should be good to go. As I recall, when you look at the two cam gears, they do not both look the same when they are properly installed. One looks to be at a different angle than the other. Just make sure the dark chain links and the dots line up, and on the crank gear that the slot in the gear points down and center, and lines up with the dark chain link.

Two notes: 1) It's been a while, so if I'm missing anything somebody please chime in. 2) I've heard stories that once those valve covers come off, they cannot be reused because they're plastic and warp or something. Google that, because I don't know how true that is. For sure, replace the valve cover gasket and you will have to use some black RTV in the corners where the gasket meets the timing cover.

The crank keyway should not be at 12:00. It should be at 10:30, and there is a groove in the crank gear that points straight down.

FYI, it's best to put the keyway at 10:30 on TDC compression before you tear the thing down. This way, everything is already where it needs to be in case something pops loose. The factory tools align the crank keyway to where it needs to be, and then holds the cams from rotating. If the rockers are off, there is no fear of rotating because there is no spring pressure and no open valves.

Remember though, that AFTER the tensioner is released, you need to still be lined up with the crank groove and chain mark, and the cam gear dots and chain marks.

 

[Silver_Shadow]

Thank you. I can take a slight sigh of relief. I will move forward as noted after the holiday.

 

[jhjr85]

Timing chain? Or something else?

So I've been reading this thread along with many others and was just curious as to what everyone thinks my issue is.
Have an 05 Mountaineer with the 4.6 V8. Has 174k miles on it. I've been noticing it for awhile... Mainly 2 syptoms, and I'm not sure if they're related or different issues.
First off, issue #1 my car is slow to start up on cold days. I have to turn the key and hold it in the Start position for 5-10 before it even begins to crank. It cranks fine, but just takes awhile to start to crank. But this is seems worse on cold days and sometimes after it has been sitting for awhile.
Issue #2 when I start it up I hear a loud banging sound like marbles on metal. First I thought it was heat shield rattling or something but I'm not sure. Noise does go away once car has had time to warm up. And even when I go to start it later... When it's still warm, it doesn't make the sound.

Any tips/suggestions?
Trying to sell/trade for a truck, but haven't been successful. Just don't know if I want to spend the time and money to fix it or not.

 

[Pontisteve]

So I've been reading this thread along with many others and was just curious as to what everyone thinks my issue is.
Have an 05 Mountaineer with the 4.6 V8. Has 174k miles on it. I've been noticing it for awhile... Mainly 2 syptoms, and I'm not sure if they're related or different issues.
First off, issue #1 my car is slow to start up on cold days. I have to turn the key and hold it in the Start position for 5-10 before it even begins to crank. It cranks fine, but just takes awhile to start to crank. But this is seems worse on cold days and sometimes after it has been sitting for awhile.
Issue #2 when I start it up I hear a loud banging sound like marbles on metal. First I thought it was heat shield rattling or something but I'm not sure. Noise does go away once car has had time to warm up. And even when I go to start it later... When it's still warm, it doesn't make the sound.

Any tips/suggestions?
Trying to sell/trade for a truck, but haven't been successful. Just don't know if I want to spend the time and money to fix it or not.

The starter problem could be a bad ignition switch, but these year Explorers had an issue with some wiring rubbing on the oil filter drainage shield's back edge. One of the wires in that small bundle that rubs the shield edge is the small starter solenoid wire. Thats the wire that runs from the ignition switch to the starter solenoid. The shield saws right thru the wiring over time, and isn't just limited to that one wire. The A/C compressor wire is in there, as is the positive battery cable. My positive cable was cut clean thru almost half way as I recall. It's a common problem on these trucks, so perform a visual inspection of the wiring harness bundle right behind the oil filter drip shield.

Other possible causes are a bad ignition switch or maybe some sort of starter relay.

As for the loud sound of marbles on startup, I have heard that exact same noise from my father's 4.6 F150. It goes away after about 3 to 5 seconds once oil pressure builds. I don't know what's wrong with it for sure, but I suspect the problem is the timing chain tensioner is not keeping spring tension on the chain, and therefore the chain is loose and rattles until oil pressure builds up in the tensioner body. I suppose it could also be bad chain guides or tensioner guides (both are plastic timing chain guides). I can't really think of anything else that would sound like that.

To completely validate that theory, you could pull the serpentine belt off the truck, let it sit for a day or two, and crank it up without the belt on. That would eliminate all noise created by all the front belt-driven accessories, and it would also allow you to safely put a stethoscope directly on the timing chain cover, right in front of either cam gear, just below the valve cover.

Any other noises should be easier to narrow down. The only other remote possibilities I can think of would be torque converter, catalytic converter heat shield, and hydraulic lash adjusters. I doubt the lash adjusters ("lifters") would make this type of racket that loud. They would just tick, and not all of them at that. The torque converter would have noise coming from the bottom, and so would the cat shield. You could tap on the cats with a rubber mallet to see if anything makes rattling noises.

There is one other thing that might be a cause. If the oil filter or oil filter housing has some sort of anti-drain back valve that has failed, perhaps all the oil is falling back into the pan. I have no idea if such a valve even exists. Let me know what you find out.

 

[rocco123]

No Pics on how OTC 6487 Cam tool is installed?

 

[Number4]

No Pics on how OTC 6487 Cam tool is installed?

If you go to OTC's website, that kit says it fits the 4.6 from '92-2012. However, when you look at each component on their website, or call their Techline, they'll say it doesn't fit the 4.6 after 1998. Same with the packaging.

I bought the 6020 and 6009 but wasn't able to use them.

After completing my timing, I saw a post somewhere and the tools I'd purchased were in place at the back of the cams. Give it a try and update this thread. Did you pick up part number 6024? Crank holding tool. It's worth having it.

 

[rocco123]

Can't find any of the tools in my area to rent. This is going down this weekend, so I'll just press on

 

[drdoom]

I finally did the job last week, both tensioners had blown seals, guides and chains were in great shape but were replaced anyway of course. The OTC 6477 was very useful, wish I had two of them! Startup rattle is eliminated.

 

[Number4]

Really? I wonder why the OTC info says it only works up to 2002?