97 SOHC Hydraulic Tensioner Failure?

[2000StreetRod]

correct tensioner?

Is it possible that you have a rear tensioner installed in the front? The front tensioner is about 1/4 inch longer than the rear tensioner from the end of the piston to the face of the housing that seats against the head.

Did you install a thick compression ring reducing the effective length of the housing?

Is the oil port in the head blocked with some obstruction?

With the engine running the piston should be extended and the amount of the extension should be fairly constant. Something is causing the guide to force the piston to its retracted position. That means that at some instant the chain on the slack side is becoming taught. Are you certain that your firing order is correct?

1-4-2-5-3-6

Remember that on the ignition coil 6 is between 4 and 5.

 

[sabasigh]

What's weird is that I haven't seen anyone else with the problem.
If it was just one tensioner, I'd say it was a bad tensioner, but as I said I bought another new one and it did the same thing.

Thanks for the reply!

WHOA...dude, this just happened to me! I bought the 00M12 kit.

http://www.explorerforum.com/forums/showthread.php?p=2564447#post2564447

I put my old (but new style) tensioner back in and hoping that I don't have any damage.

I'm hoping I can get thru winter before engine replacement.

 

[Shawshank]

Well, that makes me feel a little better...but sorry it has happened to you!
Does your old one still work okay?
The first one I bought stayed stuck in.
The second seems to work okay until the engine is running.
Then it stays stuck in until I loosen it to remove it.
It then pops out.

If I find a solution, I'll let you know.
If anyone else has any ideas, I'd love to hear one!

Thanks.

 

[sabasigh]

Well, that makes me feel a little better...but sorry it has happened to you!
Does your old one still work okay?
The first one I bought stayed stuck in.
The second seems to work okay until the engine is running.
Then it stays stuck in until I loosen it to remove it.
It then pops out.

If I find a solution, I'll let you know.
If anyone else has any ideas, I'd love to hear one!

Thanks.

Old one is back in and seems to be fine.

The new one...the plunger is fully "turtled"...it ain't coming out for nothing.

 

[Shawshank]

That's how my first one was.
Its crazy...
Thankfully my second pops out once it is loosened a bit.
Seems like it has a vacuum issue or something.

Working on it now...again.
Posted via Mobile Device

 

[Dick Berg]

Left side Tensioner Piston Stuck

Guys - Very interesting, and very strange symptoms.
StreetRod2000 is the expert on these things, in my opinion. If it has stumped him, then there's no hope...Just kidding.
I recently did the left side guide and hydraulic tensioner replacement without removing the jackshaft sprocket, and it worked out fine. StreetRod2000 helped me immeasurably during the process.
I'm just wondering if there's a lot problem with the tensioners. Is there a date code on the box that it came in? If there was a machining problem in the bore or piston of the tensioner, perhaps that's why it gets stuck in the fully retracted position. Although as has been mentioned, what could be compressing the piston that far into the bore? And now, your old one is exhibiting the same symptoms. Hmmm
Shawshank - The picture you posted showing the retracted tensioner and guide assembly looks like there could be a misalignment of the sprocket gear. And the piston doesn't appear to be centered on the guide arm. It could be just the angle that the picture was taken.
Just a thought, I wish I could offer more.
When you figure it out, let us know.

Good luck,
Dick

 

[marquis00]

Same thing happened to me after replacing the all thr timing componenets, so I am rebuilding the whole engine only to find that engine was clogged with sludge and alot of broken pieces of plastic from the old guides. The kit(00M12), does it have to be used? Also, does it help to drill a hole at the bottom of the tensioner?

 

[2000StreetRod]

Installation tool?

What tool (box wrench, open end wrench, deep well socket) are you using to install and remove the tensioner? If using a deep well socket, is there a possibility you bent the tensioner housing extension?

Is there any evidence of cross threading?

You stated that when you rotated the engine manually and watched the piston you noticed the chain went slack at times. Did the chain ever get tight enough to force the piston to the fully retracted position?

When examining my old tensioner I noticed that there was a slight "catch" near the fully retracted position. I assumed that it was due to wear from years of service. When I examined the new tensioner I was surprised to detect the same catch.

When I drilled holes in my old rear tensioner to modify it to use for a substitute for one of the OTC-6488 tools I learned that the piston is considerably shorter than its housing. It is unlikely that the piston is retracting far enough into the housing to block the oil port.

There is a very small hole in the exposed end of the piston. This may be an oil pressure relief port or it may also serve to lubricate the surface between the piston and the guide. The relief port is much smaller than the tensioner inlet port so oil pressure should rapidly increase within the tensioner housing forcing the piston to extend. If the internal piston area is say .67 sq in, and the engine idle oil pressure is 30 psi, then the piston should be exerting 20 lbs of force against the guide. As I recall, this is more than the spring pressure I experienced but not enough to overcome the piston being jammed in the housing.

This problem is really bugging me! Even a defective tensioner does not explain why it is being forced to full retraction. That's why I asked about the firing order thinking that maybe it is wrong and the engine is misfiring on the driver side bank.

 

[sabasigh]

Old one is back in and seems to be fine.

The new one...the plunger is fully "turtled"...it ain't coming out for nothing.

I drove mine for about 130+ miles last nite...all seems good with the old tensioner. Idle is improved thanks to the gasket replacement.

*edit: I used a 27mm deep well socket for intall/removal. I did most by hand turning then used the socket when needed.

 

[Dick Berg]

Hydraulic Tensioner Piston Stuck

Shawshank - Your comment about the piston releasing (popping out) when you loosened the tensioner is interesting. This suggests that the body of the tensioner may be distorting or dimensionally changing somewhat after being torqued, and when the torque is released, the piston gets freed up.
I just looked at the old left side tensioner that I replaced, and there's absolutely no indication of it sticking, even if I force the piston in as far as it can go. I also have a new right side tensioner which I'm intending to replace in the future. Same deal with it, no indication of sticking, even when the piston is forced in as far as it will go.
For reference, the date code on the 00M12 kit that had the left side tensioner is 041910, and the date code on the box that the right side tensioner came in is 021210. For these date codes, I believe that they decode to XXYYZZ, where XX is the month, YY is the day, and ZZ is the year.
I still think there could be a lot problem with the ones that you have. Some kind of problem at the factory where there may have been a machining or assembly problem that causes the piston to stick, but only after the assembly is torqued. The thing is so beefy that it's hard to see it happening, but that's what you reported. There's no doubt that torquing things can change their dimensions slightly due to material yielding.
Of course, I'm just speculating about all of this, but I have come across lot problems before.
Were the date codes the same on both of the boxes that the tensioners came in? I believe that you bought the entire 00M12 kit both times, and not the individual tensioner.
How and why the piston is being forced so deep is another story.
You might want to check with your Ford dealer to see if others have complained about this problem, and see if you can try another tensioner from a box with a different date code, given that both of the ones that you tried had the same date code.
While there's no guarantee that the date code on the box represents the build date code of the tensioner itself, it's probably worth a shot. If the date code was stamped on the part itself, then that's a much more positive indication of when it was fabricated. I don't see any date codes or part numbers stamped on the tensioners that I have.

Good luck,
Dick

 

[8donovang]

I have access to the whole TSB in the tensioner/intake gasket recall, and was wondering if when you did the tensioner you also replaced the volume reduction plug/oil galley pipe plug as per the recall directions? I've seen several times people replace the tensioner at home and still have problems with it extending right, to find the volume reduction plug was still the stock one, and very clogged.

If there's any other info you'd like from the TSB, feel free to ask.

 

[2000StreetRod]

volume reducer

My 2000 SOHC V6 in the stock configuration had no volume reducer "pencil". It is my understanding that the pencil in the 00M12 kit may also act as a restrictor slowing the oil draining from the chamber that supplies oil to the hydraulic tensioner. However, it's main purpose is to reduce the volume of the chamber so that pressure builds up sooner after engine start. The spring in the hydraulic tensioner should be strong enough to keep the piston extended until there is oil pressure. I have not seen anything in the TSB regarding cleaning the oil galley to prevent it from getting clogged.

It's a shame that Ford did not utilize the ratchet style hydraulic tensioner incorporated in the earlier 4.0L OHV engine and the later 4.6L DOHC engine as shown in the photos below. In my opinion it is a superior design.

 

[Shawshank]

When I replaced the tensioner, the kit had already been done so I didn't bother changing the restrictor. I didn't realize it should be changed even if it already has one installed.

I will change it and see what happens.

Thanks
Posted via Mobile Device

 

[sabasigh]

When I replaced the tensioner, the kit had already been done so I didn't bother changing the restrictor. I didn't realize it should be changed even if it already has one installed.

I will change it and see what happens.

Thanks
Posted via Mobile Device

When I did the replacement, my plastic oil reducer was pretty far down the plug and didn't look like I could really grab it to replace it. I used the pipe plug that came in my kit however and discarded the old.

So now I have the old tensioner, old oil restrictor rod and new pipe plug.

 

[Shawshank]

I did the same using the new plug when I saw the restrictor was already installed.
I guess I will try and rig up some kind of tool to remove the old one.

As for the date codes mentioned above, I do not have the original boxes anymore, but one was bought from Tasca quite a few months ago and one was bought from my local dealer in the past month or so.

Can anyone tell me what the rear chain noise would sound like?
Is it obvious when it's the rear chain or is it hard to tell?
Just trying to rule out chasing the wrong problem.

Is there anyway to test the rear hydraulic tensioner without putting a new one in?

Thanks

 

[janolsson]

Can anyone tell me what the rear chain noise would sound like?
Is it obvious when it's the rear chain or is it hard to tell?
Just trying to rule out chasing the wrong problem.

when my rear cassette started to go i just had a rythmic ticking most audiable at the bell housing on the tranny. I tried using a hose as a stethoscope but couldn't pin point the tick so i thought i may have damaged the pump in the tranny. Then the metal part of the guide let go and the chain snapped!
On another engine the all plastic guide failed and the rattle was constant from the chain wearing away the upper cassette mounting bolt. I could tell it was the rear using the hose on the valve covers to pin point the rattle.
HTH

 

[bmlawson2003]

So I have encountered the same issue when installing a new front hydrolic tensioner in my 2001 explorer with the sohc. The only difference is I cant get the tensiiner to come back out of the motor. On a bright side I do have a donor motor out of an 01 sport trac with about 30000 less miles on it waiting on me for wuen I need it for only 400. I was hopeing to make it thru winter but tba now seems unlikey.

 

[2000StreetRod]

tight or stripped?

So I have encountered the same issue when installing a new front hydrolic tensioner in my 2001 explorer with the sohc. The only difference is I cant get the tensiiner to come back out of the motor. . .

Is the problem that you can't loosen the tensioner because it is too tight or that the threads are stripped?

 

[bmlawson2003]

It's to tight. Plus after further examination it appears as if I cross threaded it when I installed it.

 

[Gargola033]

Hi, im new in this forum but i had solve a few problems thank to all of you. I have the tensioner problem in the rightside of my 03 sport trac. Buy the original tensioner and the same problem. Can anyone's tell me what the problem was? I appreciate it.