4.6L Explorer engine timing chain ooops!

I really don't think the cam sensor does much of anything except to tell the PCM which stroke the engine is on, so it can decide whether to fire the injectors and ignition on this stroke or the next. It also may only be necessary when first firing up the engine. After that, the PCM could just remember which stroke it's on. That part could be proved out by unplugging one after the engine is running.

You could go to a junkyard, turn a motor over to TDC, and have a look at the position of the crank sensor relative to the bump on the cam gear. Or align those two, and see where the balancer looks like it might be, relative to TDC.

The 6 cyl. has a weird cam sensor sync tool that isn't used in anything else. I think it's because it uses what used to be a distributor drive, that's now vacant due to distributorless ignition on a distributor-type engine block. The V8 doesn't do that. Here's some interesting exerpts from the 88-93 Ford Racing book on EEC-IV EFIs by Charles Probst:

"The camshaft cylinder ID sensor operatoes with only one vane and one window, turning at cam speeds. Its job is to identify the cylinder. Spark timing accuracy is not affected by the inaccuracies of the cam drive because the crankshaft PIP determines timing. The CID only determines which coil to fire. The CID signal also identifies which cylinder is on compression stroke for the sequential injection of fuel to that cylinder."

It goes on to say that some EDIS modules use a 36-1 crank wheel with a VR sensor, and that they use a trial and error method on startup to see which cycle the engine is on. If it's on the wrong stroke, it tries the other stroke. Once it gets it right, then it just remembers which one it's on from there. No cam sensor. It shows the missing tooth on the crank trigger wheel to line up with 60 BTDC.

I would think the guys at Megasquirt would be helpful in figuring this out. It's right up their alley. Report back what you find.

Hi, Steve.

I got a pos on 36 deg ATDC on the V6- nothing on the 4.6 V8 yet.

"The 6 cyl. has a weird cam sensor sync tool that isn't used in anything else. I think it's because it uses what used to be a distributor drive, that's now vacant due to distributorless ignition on a distributor-type engine block. The V8 doesn't do that."

The 302 V8 (96- 2001? Explorers) does. Same kind of CPS- where the dist. usually sit on a 69- 95 302.

In the 302- threads at the subforum for these years Explorer, I have read somewhere, I think, that the 302 is 26 ATDC as well.

Now. I'll line up the sensor with the tool and check if it comes in at 26 ATDC. If so, I'll do a try and see what happens.....

Over at modularfords.com, there is a forum that has a thread on conversions. Maybe somebody over there knows.

I had not seen the Explorer 5.0 distributorless setup before. But if you are going to use a modular computer with a 5.0 engine, then why not just use the 5.0 CPS setup? Or does it not use the same type of wave output?

Now here's something I read in Charles Probst book (page 72). The Ford distributor-mounted PIP is a hall effect device. It's output is processed- amplified and shaped. The signal becomes inverted in the process. So when the hall element generates voltage, such as wehn there is a window in the rotor vane, the PIP sends no signal. When the vane cuts off the hall-effect voltage, the PIP sends a signal. That's opposite what most car manufacturers do.

So a window = hall voltage = no PIP signal

A schmitt trigger is used (in the TFI module) that shapes the wavy output of the hall device into square digital pulses. In other words, a TFI module could be rigged up to deliver square waves, instead of the hall-effect switches sine waves.

The 5.0 EDIS setup must use that V6 type distributor replacement as a CPS, so that means it's like able to have it's timing adjusted just like a distributor, right? In that case, you could just adjust the thing to whatever timing you need for the modular engine. With an oscilloscope, you could figure out where to time it to line it up.

Noteworthy, if the engine used that fake distributor for a crank angle sensor as well, then you might have to modify the rotor vane to get rid of the other 7 cylinders. Cut their vanes off, leaving only cyl# 1.

You could adjust the distributor CPS so it's 1 point lines up with whatever crank degree that it lines up with in a mod motor. I guess you would still need to know that number though, huh?

That's interesting...

Yes- the CPS is a distributor- type, so it can be swung around to any point on the scale... Which is good. Am able to find the correct spot without modifications if I only know where the spot is!

No, it is not for a factory modular ECU. It is an aftermarket EFI- system from FAST. In order to get the ignition- box to work with a 36-1 crank trigger wheel, I have to tell the box that it's mounted to a modular 4.6 engine. I am therefore using the modular fireing- order (and therefore also injection fireing order, it's sequential). And I also have to get the signals from crank & cam in factory mod. spec.... So that is why I need to know.

You are correct that the cam signal is hall. But, that was the early models only. After 1998 I think it was, it was switched to a 2- wire inductive sensor. And this is what I have. It plugs straight into the harness (which was made for a 4.6 mod). It is a 1- tooth sensor, so no need to mod either...

We'll see how this gets along in a month.
I'll post here to let you know....

Regards
RS

Wouldn't it just be easier to tell the FAST box its a 302, and then use the 302 distributor instead of the 36-1 wheel?

Also, make sure the firing order is the same, which it would be if using the 302HO/351 firing order of 13726548. If the camshaft and the PCM firing order aren't the same, you'll have trouble (with the sequential injection order) despite having the plug wires right.

My last comment in this 4.6 thread! Finally!

Pontisteve said:

Wouldn't it just be easier to tell the FAST box its a 302, and then use the 302 distributor instead of the 36-1 wheel?

Also, make sure the firing order is the same, which it would be if using the 302HO/351 firing order of 13726548. If the camshaft and the PCM firing order aren't the same, you'll have trouble (with the sequential injection order) despite having the plug wires right.

Click to expand...

Hi, Steve.

Problem is; the FAST XIM (ignition) box have some limitations, unfortunately...
If I choose the 36-1 crank wheel, there's only one way to go with a 1- tooth cam sensor. And fortunatly, this is the 4.6- setup. Which have given the opportunity to get a complete engine harness & correct fireing order. Am going with a 351 cam, and therefore the 4.6 order.

(If I'd gone with other rype of crank wheel, the options would have been there, but then I would have had other issues....)

I have now got the cam phase sensor timing figured out by a guy at EECtuning, so thanks alot for the link, Steve. He had the engine on the rack in his workshop and checked the timing.

25 deg ATDC.

Thanks again

RS

Explorer V8 timing chain rattle

Have you considered replacing the tensioner and idler bearings? Might be worth a try before stripping the motor down. I replaced mine when I did a serpentine belt change

I'm in the middle of this very repair on my Explorer. Oddly enough, I didn't find this thread using the board's search tool but did find it with Google.

On mine, the passenger side also broke. I don't have the front cover off yet, due to the power steering pump, but I do have the valve covers off and can see into the front cover. The guide for the passenger side is floating freely in the cover; not sure about the tensioner arm. There is also a tremendous amount of slack in the passenger side chain, while the driver's side is nice and tight. I'm going to replace all the plastic pieces once I get it fully torn down. I don't believe the passenger side chain jumped time but will verify before putting it all back together.

One question - many of the instructions I've found state the power steering pump needs to be fully removed from the motor, while in this thread I read that only the pulley needs to go (there's a front cover bolt hidden behind it). When I did a head gasket job on a 5.4L Expedition a few years ago, I had to remove the pump from the motor. Which is it - the pump or just the pulley?

@Splora - when mine started making noise, I thought it was a bad idler or tensioner pulley, so I let it go for a bit, until my oil pressure went away. The tensioner and all three of the idlers are good.

As somone experienced in this, this noise been going for over a year now. Do you think a bad tensioner would hv revealed itself by now? I changed the belt tensioners and idle pulley to no avail.

I suppose it depends on how broken your tensioner/guide arms are. If there's only a little play in them, you might be able to run for quite some time (I went for nearly a month before losing indicated oil pressure, but the guide arm on the passenger side is completely broken off).

One fairly easy test, and it will only cost you a couple of hours and possibly a set of valve cover gaskets: pull the valve covers, one side at a time (start where the noise is), and check for slack in the chain. They should be tight with no play at all. On mine the driver's side is tight while the passenger side (the noisy side) is absurdly loose, and I can see the guide arm bouncing inside the front cover. If one is loose, you're in for a teardown of the front of the engine to replace whatever's broken. The parts list, for both tensioner/guide arms, front cover and valve cover gaskets, is about $125. But it will probably take you a weekend to do it, if you've never been in one of these before.

Okay, thanks I will try that out. Don't know if I mentioned before that I had the tensioners and guides replaced about 2 to 3 years ago. Don't really remember if they replaced the chain also. But I was thinking it would be awfully soon if they went again.

To JW re tensioner. Where can I get tensioner/guide arms, front cover and valve cover gaskets for $125, Ford Australia want an arm and a leg for these parts. Can I import them?

I imagine you probably could, though it could take a bit to get them.

The guides are all made by Melling (the oil pump people). Gaskets are all Fel-Pro.

Guide Or Damper BG334 $21.34 1 $21.34
Guide Or Damper BG333 $21.34 1 $21.34
Guide Or Damper BD322 $10.62 1 $10.62
Guide Or Damper BD321 $13.49 1 $13.49
Valve Cover Gasket Set VS50564R $33.48 1 $33.48
Timing Cover Gasket Set TCS46064 $17.38 1 $17.38

I completed this over the weekend. I don't have pictures, but they would have looked exactly like those on page 1. The passenger side guide was broken into three pieces, plus a lot of debris. The tensioner arm was worn completely through to the tensioner itself, which was also ground down. Chain showed no wear. The driver side guide was starting to break, but the tensioner arm and tensioner were fine. I replaced all the plastic pieces, and the passenger side tensioner, and managed to get the chains back on with the correct cam timing in the first attempt. Should be good for another 100,000 miles

Additional information that may be useful to other Explorer owners with this issue, in no particular order...

- The radiator doesn't have to be removed. In fact, I discourage it, since the radiator, trans cooler and AC condenser are inexplicably married in a most unholy union. A standard harmonic balancer puller will not fit with the radiator in the truck, but a shorter bolt from Orchard Supply Hardware in the center of the puller provided a good workaround. For the puller I had, it was a 5/8" fine thread (18 per inch, I think; Home Depot only had coarse thread 5/8" bolts). You will need to provide some sort of spacer between the end of the bolt and the crankshaft snout, so that the bolt doesn't chew up the crank (maybe a socket from that cheap auto parts store tool set you bought in a pinch that one time...).

- I had posted in another thread that I was having trouble getting the power steering pump off. Instructions I found elsewhere said it had to be unbolted from the engine (and one set of instructions even stated it had to be completely drained and removed). It simply needs to be unbolted (but all bolts need to be removed, as the bracket for the PS reservoir blocks access to one of the front cover bolts). The issue with mine is one of the bolts, attaching it to the front cover, is hidden behind a PS line on the pump. The pump has four mounting holes, and several sets of instructions I saw for Mustangs and other vehicles say only three of them need to be used. I believe this bolt was placed incorrectly at the factory and should have been in the rear hole instead of the front. I cut it off with a Dremel and a cutoff wheel between the pump and the front cover, and will add one to the rear hole soon. (You do also have to pull the pulley, because even with the pump unbolted, it won't move out of the way enough to get to the front cover bolt behind it. When I did the head gaskets on my Expedition, I had enough room to pull it out of the way.)

If you suspect your motor has jumped time due to chain slack, the next two points will NOT apply to you. Mine didn't, so I was able to use this procedure successfully. I've used this procedure on a 5.4 and a 4.6 with good results.

- Cam timing: it's not necessary to get the camshaft holding tool that Ford specifies (or the crank holding tool, for that matter). Before removing the chains, set up the engine as follows: The dot on the crank sprockets should be at a 6:00 position (this puts the keyway on the crank at what would be about a 10:30 position for the hour hand). The cam sprockets should have their dots at about an 11:00 position on the passenger side and 12:30 position on the driver side. From there, the tensioners can be removed. Note that one or both of the cams might rotate a bit after the timing chain tension is released. Not a big deal, if the motor is set up right before releasing them. You'll fix that on installation...

- Timing chain/tensioner install: This is a minimum two person job, if you don't have the holding tools. Rely on the copper-colored links on the chains, but mark them with something to make them more obvious (I used a Sharpie). Place one of the colored links on the crank sprocket, at the dot at 6:00. Then route the chain through the tensioner and guide arms, and start to place it over the cam sprocket, placing the other colored link at the dot on the cam sprocket. You may find you have to rotate the cam a bit to get it to sit right (using a ratchet and 18mm socket), and also hold the chain on the bottom of the crank sprocket. Once the links are in the right spot, you can release the hold on the tensioner, and the cam if you had to rotate it. Repeat for the passenger side.

- Find all the debris you can. I had it in all sorts of places in the front cover and the front of the engine. I didn't find anything in the pan, but didn't drop it, either. The guides seem to initially break into large pieces, but the meat grinder environment turns them into little pieces pretty quickly.

- Ford changed the design of the tensioner assembly sometime after 1998. Before, you could collapse it in a vise, and insert a paper clip in a hole to hold it (my Expedition and Ranger both worked this way). Now that hole is gone, and a retaining clip is used. I got lucky in that I had to get one new tensioner, so I used the retaining clip from it on both tensioners. If your tensioners are good, you'll need to find that retaining clip or come up with another method to collapse the tensioners. Auto parts stores didn't know what I was talking about when I asked about it, and my local Ford dealer doesn't carry any of the Ford-specified "special" tools.

- While you're in there, modify the little drip guard for the oil filter if you haven't already, so it doesn't eat up the wiring harness that sits right above it. Three 13mm bolts and five minutes, and about 3/4" off the top and that's it.

I would probably do at least one low-mileage oil change, and cut the filter open to see what you find. But put enough miles on it to actually have time for the filter to catch the pieces. The modular oil pump gears don't take too kindly to chunks going thru them.

Ford makes two tensioners. The older cast iron tensioner with the little plastic one-way ratchet device and the newer composite tensioner that uses the retainer clip to hold it compressed while installing. New tensioners generally come with the new clip.

In racing, we have found that the old tensioners are much better. The newer design fails more often. Also, the newer design doesn't have the ratchet ladder, which helps to compensate for chain stretch by keeping the chain slack taken up. Once the motor is running, the oil pressure against the tensioner keeps the slack up, so it's really only about starting the vehicle and stretched chains.

You can take the old cast iron tensioners apart pretty easy. There's not much too them. You should be able to disassemble, clean, and inspect them. I think the only thing that could really fail in them is the teflon sealing ring that acts like a piston ring for the tensioner piston.

If you have the old style tensioners, DONT throw them away. They're hard to come by, and Ford quit making them, and they're better.

OK I am thinking this is my problem with my new to me 03 4.6 Explorer. Here is a video of the noise that just started yesterday.

Any suggestions please feel free to contact me. BTW with belt off noise still there and with increased rpms noise matches rpms

Hey, How did you get my car? Lol. Seriously, that sounds exactly like my engine. It's an 02 with 198k, but the noise probably started at about 160k. I do a long commute, so it didn't take long to reach 198k.

Anyway, how long has your engine been making this noise? Everyday day I have my fingers crossed hoping whatever it is doesn't manifest itself on the highway.

I let a couple mechanics listen to it, and none had a definitive answer. Please, if you get any answers post it.

Thanks!

kware1 said:

Hey, How did you get my car? Lol. Seriously, that sounds exactly like my engine. It's an 02 with 198k, but the noise probably started at about 160k. I do a long commute, so it didn't take long to reach 198k.

Anyway, how long has your engine been making this noise? Everyday day I have my fingers crossed hoping whatever it is doesn't manifest itself on the highway.

I let a couple mechanics listen to it, and none had a definitive answer. Please, if you get any answers post it.

Thanks!

Click to expand...

Mine started that noise Sunday, two days ago. I plan on getting a deepwell 8mm socket to get the Valve cavers off and check everything out hopefully tonight. I assume that the the chain will be loose if the tensioner or guides are bad but not sure if there is no oil pressure on tensioner.

Could be a broke tensioner, guide, or tensioner arm. Pop the valve cover off and have a look at the chain, and the rest of the valvetrain on that head while you're at it. If the chain has any slack in it at all, something's wrong and the timing cover has to come off.

You could also drain the oil, and look for pieces of nylon/plastic in the oil, from the guide or tensioner arm. You might try a stethoscope on that side as well, to better narrow down the noise before disassembly.

I've heard a broken guide/arm before, that sounded just like a knocking motor to me.