97 SOHC Hydraulic Tensioner Failure?

[Shawshank]

Hey guys,

First thanks to everyone who posts to these boards as you have saved me a lot of time and money. Now for my problem:

I recently decided to go ahead and put a new hydraulic tensioner in the left head due to increased chain noise. Well, after installing it, the noise was much worse. I let it run a few minutes to see if it would build up oil pressure and increase the tensioner strength. It didn't. I pulled the valve cover off and found the hydraulic tensioner stuck all the way in and the guide broken.

So, I purchased the left cassette and jackshaft tensioner/guide and installed them. I followed the trick posted here about replacing the cassette guide only and not removing the jackshaft sprocket. I pulled the oil pan and pickup and removed all the broken pieces of the old guides (orange).

I assumed the hydraulic tensioner was just ruined by the guide breaking so I bought another and installed it today. But, the same thing happened. I let it run for about 5-10 minutes but the noise is louder than ever and upon removal of the valve cover I see the hydraulic tensioner is stuck up. I haven't been able to find anyone else with the same issue!

Can someone help me figure out what the heck is causing the issue with the hydraulic tensioner?


Thanks!

 

[1998Explodasport]

Are you sure you're using the the tensioner for the correct side? I replaced my driver side tensioner/left hand side and Ford actually gave me the wrong tensioner. They gave me the tensioner for the pasasenger side/right hand side.

 

[Shawshank]

Yes, it is the one with the long extended neck.
I have bought the "recall" kit both times since it's cheaper than just buying the tensioner itself.

Thanks.

 

[2000StreetRod]

Very interesting problem!

By the recall kit are you referring to the 00M12 kit shown below?

The photo below compares the front and rear hydraulic tensioners. The front tensioner is the left one in the photo.

There is an oil port in each tensioner identified by the red arrow in the photo below of the rear tensioner.

The spring should keep the piston extended as shown in the photo without oil pressure. There is a port in the head that supplies pressurized oil to the port in the tensioner.

Are you saying that after you install the guide assembly and tensioner and run the engine for a few minutes the tensioner piston stays in the retracted (rather than extended) position? Is it in the position shown in the photo below?

 

[Shawshank]

Yes that is the kit (00M12)I am using.

Yes, the spring is extended when I install it, but after running for a few minutes it will be stuck in the retracted position.

The old one (but updated version) works as it should but is too weak to hold the correct amount of tension.

Thanks!
Posted via Mobile Device

 

[Shawshank]

I don't have to make sure the hole in top of the tensioner lines up exactly with the hole in the block do I?

 

[2000StreetRod]

variable tension

I don't have to make sure the hole in top of the tensioner lines up exactly with the hole in the block do I?

No, the tensioner oil groove around the circumference allows oil to flow no matter what the orientation of the tensioner port relative to the head port.

Did you happen to check the new tensioner to see if the piston moved freely (except for spring pressure) before you installed it?

When the engine is not running the tension on the chain and the displacement of the tensioner piston varies according to camshaft position. When the cam lobes are depressing the valves the chain will be much tighter than when the valves are closed. When the engine is running the jackshaft sprocket is constantly pulling the camshaft sprocket quickly enough that the tension in the chain stays more constant. I suggest that with the valve cover removed you rotate the engine manually with a breaker bar and socket applied to the balancer retaining bolt to see if the hydraulic tensioner piston face stays in contact with the guide.

I also suggest that you check the camshaft timing to make sure it is correct before running the engine.

 

[Shawshank]

Yes, I checked the tensioner before installing and it worked fine. When I installed it it was touching the new guide and was extended a bit. It wasn't until I ran the engine for a few minutes that it apparently was pushed all the way in somehow and stayed there.

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!

 

[2000StreetRod]

New guide assembly?

What is the condition of the new guide assembly?

Did you install a Ford cassette or an aftermarket unit?

Can you post a photo showing the tensioner installed in the vehicle in it's retracted position?

 

[Shawshank]

I installed the Ford direct cassette.
Here is a photo of the tensioner.

Thanks!

 

[2000StreetRod]

Very Strange!

That is very strange and frankly I'm at a loss as how that could have happened. The tensioner appears to be installed correctly. It is not at an angle due to cross threading.

The piston appears to be fully retracted into its housing. The piston is hardened steel and not easily damaged. I had to use a diamond pointed drill to slightly enlarge the hole in the end of the piston.

Even if the spring between the piston and the end of the housing had broken I think the oil pressure at engine shut off would leave the piston slightly extended.

The guide assembly does not appear to be damaged. Does it move freely between the chain and the tensioner?

I suggest that you check the camshaft timing:

With the #1 piston at TDC on its compression stroke the camshaft timing slot at the rear of the camshaft should be below the centerline of the cam and parallel to the head surface that mates with the valve cover as shown in the photo below.

After you confirm the timing is correct I suggest that you use a breaker bar and socket applied to the balancer retaining bolt to manually rotate the engine clockwise while watching for abnormalities in the vicinity of the tensioner piston. Something apparently is forcing the piston to retract past its limits causing it to stick in the housing.

 

[2000StreetRod]

bolts & sprocket

The photo below by CDW6212R shows the cassette bolts and the camshaft sprocket.

Are you sure that you installed the upper torx head bolt and the lower hex bolt that positions the timing guide assembly correctly? Is it possible that the camshaft sprocket is installed with the front facing to the rear?

 

[Shawshank]

Yes, the guide assembly moves fine and will contact the tensioner when I push it over.
I am also sure that the guide assembly is installed correctly with both bolts being in the proper place.

I will try to rotate it by hand tomorrow to see if anything looks strange.
I know I can put the old tensioner back in and it will work (not be pushed all the way in) but it is not as strong so there is some rattle.
I would hate to ruin a new cassette guide because of the slack!

I will also check the cam sprocket again but I know I put it on correctly and have checked it once.

It's really strange (but about my kind of luck!)

Thanks for the replies, I appreciate it.

 

[2000StreetRod]

tightening the sprocket bolt

Did you check the piston to see if it was still extended after tightening the camshaft sprocket retaining bolt? If you don't have the timing tool set then you probably held the crankshaft from rotating with a bar and socket installed on the balancer retaining bolt while you tightened the camshaft sprocket retaining bolt. That makes the slack side (with the hydraulic tensioner) become the traction side since the camshaft sprocket is trying to pull the jackshaft sprocket via the timing chain. During the process the tensioner piston will fully retract due to the tension on the chain deflecting the guide assembly and pressing against the piston. If you used the timing tool kit you would have installed a calibrated tensioner that tensions the chain and prevents additional guide assembly deflection. However, when I tightened the camshaft sprocket bolt on my engine, I inserted a socket (acting as a spacer) between the tensioner and the guide. This resulted in the tensioner piston being fully retracted but I experienced no problems after removing the spacer.

I just realized that I used my old rear tensioner for both the rear and the front when tightening the sprocket retaining bolts. Maybe the front tensioner gets damaged if the piston is forced to fully retract.

 

[Shawshank]

Update: I went to remove the tensioner and when I loosened it a bit it popped out. I confirmed the chain was tight and put everything back together. It still had a terrible noise. I removed the valve cover again and set the motor to TDC and can confirm that it is timed correctly. The camshaft itself is correct on the rear slots and the CPS nub is oriented correctly.

I am now at a loss as to what the noise is. The engine runs, but sounds terrible. I thought maybe it was so far out of time that it had piston slap, but I never removed the jackshaft sprocket so I know the right cam is the same as it has always been and now I know the left cam is exactly where it was when I started.

Any ideas?

Thanks.

 

[2000StreetRod]

#1 piston on compression stroke?

The engine will run (poorly) with the left camshaft 180 degrees off. When you checked the timing of the left camshaft did you confirm that #1 piston was on the compression stroke (both cylinder valves closed) when the crankshaft is at TDC? If not, then I suggest that pull the #1 spark plug, rotate the engine manually until you detect pressure in the cylinder, then align the crank at TDC. You may be able to see the left camshaft nub thru the oil filler cap if you've already installed the valve cover.

You are taking a risk running the engine until you confirm the timing.

 

[Shawshank]

I double checked to make sure the cam was timed correctly.
However I now notice that when I crank it by hand sometimes the chain gets slack in the bottom on the left cam. It seems at TDC or 180 off the chain is tight but in between the chain gets loose at the bottom. I can't figure out how that could be happening.

Can anyone verify that it is supposed to do that or is it possible the gear at the bottom is bent or missing a tooth or something. Since I didn't remove the jackshaft sprocket I couldn't see it. Would that cause the chain to become more slack at the bottom at certain times?


Thanks

 

[2000StreetRod]

That's normal

Its because of the valve springs and camshaft lobes interaction.

 

[Shawshank]

Good to know.
Still chasing this noisy racket.

Thanks!

 

[Shawshank]

I am still having issues with chain noise. I have confirmed the engine is in time.

If I rotate the engine by hand, the tensioner seems to work fine.
However when the engine is running, it never extends.

I decided to put the old tensioner (new style though) back in to see what happens, and it doesn't seem to be working properly either.

What I mean is that if I take off the oil cap and watch it while the engine is running, the tensioner is not going in and out like I assume it should be.
If I take the tensioner completely out, it extends properly.

Since nobody else seems to have encountered this issue...I'm stumped!