Solved TSB 02-7-6 4.0L SOHC Timing Chain Rattle

[CDW6212R]

Welcome Lars, is there any chance that you can find out if the front cam chain tensioner was done, and when? That front tensioner is near to an oil gallery port which needs a check valve. Most work including that tensioner includes adding the check valve.

You should hope that for some reason the check valve isn't yet installed, because that is part of the easiest work to do. You can remove the upper intake to get to those, and do that job in a couple of hours. The first TSB had a kit part number for it which includes the parts to do that check valve and tensioner, about $45.

Just like Ford did back during the recall period, you do that first and hope that the more internal parts are okay. Try to find out from the seller, otherwise you are ending up doing that TSB kit to hope that it hadn't been done, etc. Good luck,

 

[khx]

fixed and back

i brought my 98 sohc to the dealership to get it fixed, they replaced everything and now its back again only after 10k. personal friend with the dealer owner, dont think the mechanics would screw me over, i dont want to take it back to get it fixed because i cant be w/o my truck for another few days so screw it for now.

 

[chinesemechanic]

does anyone know where i can find the rear timing chain tensioner online or do i have to go to a dealer to get it?

 

[Lars Jonsson]

Hi Don!

And thanks a million for answering my questions.

I found out that the seller never installed the tensioner kit as he said he did. So now i´m going back next weekend to let him do the job.
I can hear a slight rattle all the time and at aprox 2800rpm i can hear i clearly from the drivers seat even when driving.
Is it safe to use the car? The seller is 190 us miles from where i live.

I suspect that he maybe did put something in the oil to make the car more quiet, (if that i s possible). So i changed the oil and oil filter. Ford recommends 10w-30 oil but i got a tip using 10w-40 semisynthetic instead. What do You recommend and why?



Best regards, Lars Jonsson

 

[frickea86]

I use 5w30 Pennzoil Platinum Full Synthetic, i recommend a full synthetic but no oil is going to stop that noise, just prolong the damage. I don't recommend a semi synthetic. The weight depends mainly on your preference an location.

 

[CDW6212R]

I just changed to the Amsoil 0-30W, but for noises and loose parts a slightly heavier oil can prolong things a bit. Don't change oil just to get a different weight in it, but if it is due, the I'd use a 20-50W oil until you do the engine work.

If the noise is minor you might be just fine to drive it carefully to get it fixed. But don't push it too much, or turn it too fast, like over 3000rpm.

The process that Ford went through for trucks with noises was okay. They did the front cam tensioner first(TSB kit - with check valve), then if the noise was not gone thet did the front cassette. I'd do both cam tensioners at the same time no matter what, do the cassette if you can get it done at the same time. Good luck,

 

[S1L1K0N]

Hey Lars, how many km's/miles on your Explorer? I purchased mine with 152,000 kms, (~90,000 miles). After tearing it down and inspecting everything I found my primary chain tensioner was really sloppy, but the rest of the parts looked to be in good shape, there was no cracks or missing pieces of plastic. I'm guessing the owner traded it in shortly after the chain started to rattle. The front camshaft tensioner and oil check valve were already upgraded, but I don't know by whom or when.

I had read a thread on here saying STP oil treatment would silence the rattle temporarily, I thought I'd give that a shot until I could get around to pulling everything apart and I couldn't hear any difference. My rattle was continuous between 2500 and 3000 RPM, cold or hot.

Doing it yourself is definitely possible, just make sure you remember all the little details along they way - and remember that the crankshaft pully is ultra deep...

 

[sherlocktk]

Just started hearing the signs

My Fiancee/Me have a 2001 explorer sport. The car has the exact symptoms mentioned in the TSB (aka sounding like diesel at 2500 rpm).

It has 99k miles on it, and I have been reading this thread for hours getting my head around this problem. What I have got out of it is there are 2 ways to approach this problem.

1. Replace the timing chain tensioner(s) tensioner. Front one is easy, back on is not too bad. Does not require any special tools. Hope it works and noise goes away.

Use Ford

YL2Z-9E473-AA (~$42)
for the front as it has an updated plastic thing to help with oil pressure. Im not sure of the PN for the rear tensioner, and Im not even sure if it needs to be replaced (anyone know the part number?). I read somewhere this one is not as much of an issue for some reason.

2. In addition to #1 buy kit, and it better fix the noise, other wise much $$$$

2U3Z-6D256-DA (~$140)

which has all the tensioners for the jackshaft chain, and new sprockets. This requires special timing tools ($175) and I think you need a special/modifed pulley puller to get the drive shaft pulley off.

As long as you are messing with the timing, you might as well replace the front cassette with ford
4L2Z-6M289-AA (~65).

Step 1. Costs like $50, but I just dont have high confidence in it.

Step 2. Costs like $200 in parts, and then another $200 for special tools.

I guess my question is how long does step one take to install and test? (Im not a professional mechanic, but I would say I am above average for home mechanic) Should I just spend the 4-500 and do both step one and two?

 

[CDW6212R]

Welcome to the site, and you have almost summarized the issues well.

The rear cam chain tensioner is the easiest task, and that one is about $30. Both of those type have springs inside of them which wear out, become weak. Whether that happens at 50k, 100k, or 150k, how much is it worth to keep them in top condition(rhetorical)?

The front one(TSB $43 kit) is a mild task, because the upper intake has to come off to get to the check valve plug(right next to the tensioner). Those two jobs would be worth doing alone if you think that the noise is relatively minor, or at start up only.

Those tensioners have to come out to set the cam timing, but having done the intake R&R once, it isn't so bad to do again. Regards,

 

[sherlocktk]

So im looking for the part number/description of the rear timing chain tensioner.

Ive beend digging on different sites, and I came up with these 2 descriptions.

Tensioner, explorer, mountaineer, upper - 4.0l sohc - 4.0L SOHC 97-04

Tensioner, explorer, mountaineer, lower - 4.0l sohc - 4.0L SOHC 97-05

I think I need the upper tensioner? Is this correct? Is does not display front/back so is it the same part for both?

 

[CDW6212R]

Contact Fast Parts Network, send them a request for the information, they should be able to help a lot, price also. That rear chain tensioner is unique, not the same as any other part. Take the old one out, install the new one with 42lbs.ft. of torque. Regards,

 

[VonoreTn]

As a Ford engineer who worked in engine design for years before I retired, I would like to comment that it is not appropriate to blame Detroit for this failure mode. This 4.0L SOHC engine is a Cologne Germany engine, designed by German engineers. I have no idea what the root cause of the tensioner failure is, maybe a bad tensioner material selection or insuffient oil being feed to the area would be guesses. I will comment that German engineers in general do not cut corners, it must be something very subtle that did not show up in normal testing.

I worked on the 4.6L SOHC engine design in Dearborn, and it does not have this issue, and drives both overhead cams by chain from the front of the engine. Yeah, it's easier to do that with a 90 degree bank engine. None of the Dearborn Modular engines including V6's use the jackshaft cam chain drive. Our design target at the time for the 4.6L engine was 150,000 miles. If you accomplish 150K, you are likely to inadvertently also achieve 200,000 miles, since testing data at those miles is expensive to get, so you throw some money at the components as a safety factor.

That being said, I have a 2000 Explorer with the 4.0L engine with 156,000 miles, it has made this noise since 60,000 miles. It runs good but the road mileage has dropped from 24 mpg to 22. A dealer supposedly "fixed" it at 72K, but I think all he did was the front cam check valve, because the startup rattle did stop, but the chain noise overall did not. Plus it only took him about 2 hours. Since he did it for free outside the extended coverage, I didn't ask questions. Now the startup rattle is creeping back, but the bigger issue is the loud 2500-3000 chain noise. It is getting louder and I'm pulling the front cover over Christmas. I will post pictures of what I find. Thanks to everyone for providing this very informative forum topic.

 

[frickea86]

The origin of the problem is due to the check valve allowing too much oil to drain back and does not supply enough oil to the chains which causes excessive ware on the cassette and tensioner.

I believe the ford TSB fixes the check valve and the front tensioner & cassette but only the front. The noise is probably coming back due to the rear tensioner and the added noise from the front becoming lose/warn out once again.

 

[CDW6212R]

The check valve does not exist in pre 2002 trucks I believe. The TSB adds the check valve, a plastic part which holds some oil up at the tensioner when off. That is why the older engines had/have the cold start noise, without a check valve there, it takes time to push enough oil up to the tensioner. I would like to know if and why the rear head had no check valve, the heads are the same. Maybe the left head having the tensioner to the lower side keeps plenty of oil there when off.

 

[VonoreTn]

Does someone have pictures of the actual check valves? I'm having trouble visualizing what they actually are.

 

[frickea86]

The check valve does not exist in pre 2002 trucks I believe. The TSB adds the check valve, a plastic part which holds some oil up at the tensioner when off. That is why the older engines had/have the cold start noise, without a check valve there, it takes time to push enough oil up to the tensioner. I would like to know if and why the rear head had no check valve, the heads are the same. Maybe the left head having the tensioner to the lower side keeps plenty of oil there when off.

That I did not know, I thought the check valve was too big or non-functional, seem to learn new things everyday. I wish I was doing this but the trans rebuild set me back... Guess here in another year or so.

 

[CDW6212R]

My 99 engine had a check valve, likely from the one TSB having been done before. The check valve has been in a picture someone posted of that TSB. It is basically a plastic shaft about five inches long. I think that it just plugs the oil fill oil at the bottom of the hole where the tensioner's oil comes from. Its length is probably just to be able to reach it fro removal. It drops in the hole, and you reinstall the plug.

 

[diy]

Remove/Replace Camshaft Followers?

98 SOHC 4x4 Vin code "E" 115k miles

I've got the engine opened up (crank pulley/HB removed, engine front cover removed) and visually confirmed that not only has the LH camshaft tensioner broken up, but the primary chain tensioner has large visible cracks and looks ready to break up as well. (See attached photo) I obtained both the TSB kits listed above and the OTC 6488 toolkit and I'm ready to remove the jackshaft sprocket - but I have a question that I haven't been able to resolve. The (online) Helm guide states that the cam followers should be removed - which requires a specialized valve spring compressor tool (Ford 303-567).

None of the threads I've found here seem to mention either the tool or R&R of the cam followers- is this an essential step or can it (along worth the tool) be safely omitted?

Many thanks for the great info here, especially the detailed info on how to coax the crankshaft pulley off - that was a real challenge!

-Rick in Redwood City, CA

 

[travissines]

after expiring the engine in my 1998 explorer (which we now call the exploder) I replaced it with a bone yard engine that had approx. 55,000 on it and I did replace the tensioners at that time but was not aware of this check valve issue is this something that is a must do. Ability is diffenitly not an issue just finding the time. but Iwould rether replace that before the engine agaian any day

thanks for the advice

 

[CDW6212R]

...The (online) Helm guide states that the cam followers should be removed - which requires a specialized valve spring compressor tool (Ford 303-567).

None of the threads I've found here seem to mention either the tool or R&R of the cam followers- is this an essential step or can it (along worth the tool) be safely omitted?...

Welcome Rick, hopefully you are now ready for the good part, the fun part.
The cams and valvetrain assemblies do not have to be separated in any way. They stay together untouched for the cam chain work.

Before you do anything else, place the engine at TDC. Do not remove anything before placing the engine at TDC.

Verify that the engine is at TDC before loosening any of the jackshaft or camshaft bolts. As soon as one of those bolts is loosened, the connection between the crank and each cam is lost. The cams will move to their most convenient location based on valve spring pressures and rotation in the firing order.

The crank and each cam are timed at one location, at TDC. If they start there, then the cams will not move very much at all. The tools are used to positively locate the crank, and one cam at a time.

Look carefully for debris in the oil pan. If you find any, it would be wise to drop both pans and change the oil pump, clean the pickup. Good luck,