New cam chain seems to slap when turned by hand

I just finished up installing timing chains, guides, and tensioners on my 2001 4.0 SOHC. Everything went together smoothly but I noticed something I thought to be strange while rotating the crankshaft by hand to check how the motor feels. The cam chain on the back of the motor for the passenger side cam seems to lose tension periodically and get a little bit of slack on the guide side (the side of the cassete not actuated by the tensioner). Everything went back together so well I have to believe this is normal but I just wanted to be sure.

Is it maybe since there is no hydraulic pressure on the tensioner?

Thanks,
Brian

Normal slack

Unfortunately, this is normal for the SOHC V6 engine. One particular time that it occurs is during the exhaust stroke when the intake and the exhaust valve for a cylinder pass maximum valve spring compression. The spring pressure forces the camshaft to rotate forward creating slack in the traction side of the chain. Since there is no oil pressure only the tensioner spring pressure keeps tension on the chain. The OHV V6 primary tensioner is a superior design that utilizes a ratchet/hydraulic tensioner that prevents any significant slack on either side of the chain.

It is my opinion that the most likely time for the chain to slip is when oil pressure is low or when the engine misfires. The SOHC V6 should never be rotated counter-clockwise manually since the slack side of the chain becomes the traction side and the traction side becomes the slack side with no tensioner.

Thanks for the quick reply. After finishing this job I now see where the timing design of this motor leaves a lot to be desired. I just hope I get several good trouble free years to justify all the work that was involved.

Thanks again,
Brian

Hi guys, I have yet another question for those of you that have done the chain replacement job. On the startup after reassembly, how long should it take for oil to get to the tensioners and quieten everything down. I just started mine up and it ran for about 30 seconds or a little more louder than it ever was before. Do I just need to let it run a bit more or should I worry.

Thanks in advance.

Another update, I let it run for another minute or so. It is still VERY loud but it came down to a stable 1,000 rpm idle.

You did replace the tensioner piston things right?

Those two plug like deals on the bottom of the picture.

Yep I sure did. And they had a noticeably stronger spring tension than the old ones.

Pre-oiler

Did you make sure the oil ports in the heads that supply oil to the hydraulic tensioners are not blocked. Did you install the oil galley volume reducer (plastic pencil) that is part of the 00M12 kit?

When I install my engine after completing my timing chain repairs I'll also be installing a pre-oiler (Accusump) that will pressurize the hydraulic tensioners prior to engine start. Besides extending engine bearing life the oil accumulator should significantly reduce the possibility of timing chain slip.

In response to the checking oil ports, I did not carefully inspect them but it ran almost perfectly quiet before taking it down which makes me pretty confident they were ok. The motor was beautiful inside, no sludge whatsoever, I am guessing it had a blessed 140,000 miles with frequent oil changes.

But about the oil galley volume reducer, I bought a Borg Warner timing set instead of the ford kit so it did not have the parts that were included in the 0012m kit. Could not installing the oil galley volume reducer account for any of the new noise that the motor never had before being torn down.

I just recalled something that may be a problem though. When replacing the tensioners, I am pretty sure the new ones did not have the sealing washer like the old ones did. Could this possibly make the tensioner go too far into the bore so the oil port wont line up and starve the tensioner for oil??? I checked to see if there was oil leakage from the tensioner areas on my brief startups and it appeared all dry.

When I get home today I am going to pull the rear passenger side tensioner to confirm the lack of washer and see what I can see of the oil passages.

Thanks again

Well, pulled the easy to get to tensioner and sure enough there is no sealing washer. Surprisingly enough neither tensioner is leaking though. But the motor sounds like the worst chain noise known to man. From beneath the vehicle it sounds deep within the bottom of the block but from the top it is just very ticky like diesel knock almost.

On to my next question, I have seen a lot of talk about the newer 4.o SOHC's from the 05-10 mustangs and newer explorers being able to swapped into my 01 with just a swap of exhaust manifolds, valve covers, intake, and accessories. I have seen many of these for around $700 for less than 50,000 miles on them. I am seriously considering going this route rather than trying to troubleshoot what has went wrong. Just to clarify if it came from an explorer I would need a 2wd since mine is 2wd due to the balance shaft ordeal correct?

No tensioner compression ring

stangsteeda said:

In response to the checking oil ports, I did not carefully inspect them but it ran almost perfectly quiet before taking it down which makes me pretty confident they were ok. The motor was beautiful inside, no sludge whatsoever, I am guessing it had a blessed 140,000 miles with frequent oil changes.

Click to expand...

If it was quiet before then the port was probably not restricted.

stangsteeda said:

But about the oil galley volume reducer, I bought a Borg Warner timing set instead of the ford kit so it did not have the parts that were included in the 0012m kit. Could not installing the oil galley volume reducer account for any of the new noise that the motor never had before being torn down.

Click to expand...

The oil galley volume reducer should only make a difference at engine start. As soon as the galley pressurizes the chain should become quiet.

stangsteeda said:

I just recalled something that may be a problem though. When replacing the tensioners, I am pretty sure the new ones did not have the sealing washer like the old ones did. Could this possibly make the tensioner go too far into the bore so the oil port wont line up and starve the tensioner for oil??? I checked to see if there was oil leakage from the tensioner areas on my brief startups and it appeared all dry.

When I get home today I am going to pull the rear passenger side tensioner to confirm the lack of washer and see what I can see of the oil passages.

Thanks again

Click to expand...

The relief on the tensioner for the oil flow more than 1/4 inch long. The only impact of no compression ring might be an external oil leak. A tight fitting thick washer might cause some restriction.

Replacement long block

stangsteeda said:

. . .
On to my next question, I have seen a lot of talk about the newer 4.o SOHC's from the 05-10 mustangs and newer explorers being able to swapped into my 01 with just a swap of exhaust manifolds, valve covers, intake, and accessories. I have seen many of these for around $700 for less than 50,000 miles on them. I am seriously considering going this route rather than trying to troubleshoot what has went wrong. Just to clarify if it came from an explorer I would need a 2wd since mine is 2wd due to the balance shaft ordeal correct?

Click to expand...

A Ford SOHC V6 long block from any Explorer, Mountaineer, Ranger, Mustang or Discovery 3 should be compatible. The only difference is the crankcase breather on the top of the block. The Mustangs have the hole plugged. You just have to pop out the plug and insert your old breather.

Did your chain fail before prompting you to replace it? If so, maybe you had some valve damage. Have you done a compression check since replacing the chains?

More Info. Please

Not sure about those washers. I almost remember something about not all replacements require them or just a difference in torque. Not sure, hopefully Dale will know.

We should start at the beginning, what exactly have you replaced?

Is this a 4x4 engine that has a balance shaft? Did you replace that chain, tensioner and guide?

Did you pull the pins? The front tensioners have hand grenade like pins to keep them in place until installed. (see picture)

(I swiped this picture from 03silversvt)


I know it sounds stupid to think you may have not pulled a pin, but we just went through a big deal with a guy who had
a couple spark plug wires switched. No one ever ask him about the simple stuff.

Pictures are good too. Everyone has a camera and someone might see something you missed.

The more info the better.

Bob


Go Hawks...

Thanks for the info guys.

I did not break a chain before I took it down so I havent checked the compression. I may check the compression just to confirm I didnt bend any valves while assembling (if it's even possible to bend a valve by hand?) or in my startups.

What prompted me to do all this was a few months ago the motor acquired a mild chain noise that didnt go away after it started up and got warm. It was relatively quiet and could almost be mistaken for an exhaust leak but many opinions agreed it was not. I just chose to take the full preventative maintenance leap instead of risking a chain breaking.

It is a 2001 2wd so no balance shaft, motor has 140,000 miles on the clock and is backed by a manual trans. The parts I replaced were chains, sprockets, guides, and tensioners for both cams and the jackshaft.

I am certain I pulled the pin because I actually saw it the other day under the toolbox where it got kicked lol. I used the OTC timing tool kit and followed procedures from my FOMOCO service manual. I will begin pulling the motor again and hopefully have it out this weekend so I can get some pictures for you guys.

Thanks again for all the help fellas!

Tensioner compression ring

The replacement rear hydraulic tensioner is now being shipped without the compression ring. The 00M12 kit includes the compression ring. I have added the part number for the compression ring to my list of parts in my SOHC V6 Camshaft Timing thread. I suggest installing a new compression ring everytime since that allows a lower torque setting making future removal easier.

OMG, your pulling the motor back out?

Although I would much rather pull the motor than go through the hassle of pulling the intake in vehicle and still find out the motor is crap or I need to go deeper to troubleshoot. I am pretty convinced I want to get a newer motor though unless it is something stupid simple which knowing my luck and the way it sounded I seriously doubt.

Well now that I have had a day or so to calm down from all the frustration I think I am going to pull the intake and valve covers this weekend. I am thinking the only thing that could cause the noise to be this bad (assuming the tensioners are pumping up and funtioning) is that the intermittent slack in the traction side of the the right (rear) cam chain taht I mentioned in the first post of this thread was actually too much and it is slapping around.
Is there anything else you guys would recommend for me to check?

Thanks again,

Compression test

I again suggest that you perform a compression test to gain more information. If all 3 cylinders on one bank read low that indicates the timing isn't correct. If only one cylinder reads low then it could be a sticking valve.

The rear timing gets noisy when the chain slaps against the guide assembly upper positioning post. With the Ford guide that usually doesn't happen unless the guide assembly is broken. Are the Borg-Warner guides identical to the Ford guides? I was told by a Cloyes engineer that their sets use the same guides as Ford.

When you pulled the engine to replace your cassettes did you find anything failed?

Jackshaft rear plug?

Which style jackshaft rear plug did you install? Did it have an all metal exterior like the original one shown below?

Or did it have a 1/2 inch diameter rubber center like the one shown below?

If it was the new style did you install it with the all rubber covered side facing in or out? How deep did you drive it in? Maybe its contacting the jackshaft rear sprocket retaining bolt. I could not find Ford instructions on which way to install the new plug so I chose to install as shown below.

It resulted in more clearance between the plug and the jackshaft sprocket retaining bolt.