Is my timing chain loose on my V8 4.6L?

[SyberTiger]

I'm working on replacing my intake manifold but thought I might as well replace the valve cover gaskets since they are starting to weep. As you can see, below, I removed the passenger side valve cover which exposes the top of the passenger side camshaft sprocket. See the red arrow in the picture...when I pull on the chain outward from the sprocket I notice the chain will pull away from the sprocket about 1/4". On the opposite side of the sprocket the chain is taut. Are both sides supposed to be taut or is it normal for there to be some play where the red arrow is?

 

[drdoom]

IIRC that is the traction side and it will be tight when the crankshaft is turning.

 

[Hugh Janus]

The tensioner is underneath on the right side. You need to look down and check the cassette for wear. https://sites.google.com/site/hobbyhintstricksideas/Home/ford-4-6-timing-chain-repair for some pictures of what wear looks like.

 

[drdoom]

No the tensioner is on the non traction side (left).

 

[Hugh Janus]

No the tensioner is on the non traction side (left).

Yep. On the right side, the tensioner is located underneath. On the left side the tensioner is located on top. "right and left" refer to the engine. It is not easy, but you want to see if the tensioner is racheted all the way up and/or the guide worn to the metal.

 

[SyberTiger]

So, what you all are saying is that the slack is normal because both camshaft sprockets turn counter clockwise as viewed from the front of the engine? And, when the engine is turning the slack is picked up by the chain tensioners?

 

[Hugh Janus]

So, what you all are saying is that the slack is normal because both camshaft sprockets turn counter clockwise as viewed from the front of the engine? And, when the engine is turning the slack is picked up by the chain tensioners?

Other way, but otherwise correct. My point is that you have to look down inside to see the wear on the guide and tensioner. Pretty common for them to be worn out at 150k miles on motors with iffy oil changes.

 

[drdoom]

No I believe it rotates clockwise.

 

[drdoom]

A couple months back I replaced the timing components in my V8 due to start up rattle. There are two small "cheez whiz" hydraulic seals that blow out. Do you have start up rattle?

 

[SyberTiger]

Other way, but otherwise correct. My point is that you have to look down inside to see the wear on the guide and tensioner. Pretty common for them to be worn out at 150k miles on motors with iffy oil changes.

Oops, duh...I was looking at it like the cam turns the sprocket when it's the crank that turns the crank sprocket, therefore, it should turn clockwise like you said.

 

[SyberTiger]

A couple months back I replaced the timing components in my V8 due to start up rattle. There are two small "cheez whiz" hydraulic seals that blow out. Do you have start up rattle?

I don't have any rattle sound from what I can tell. I do, however, have a clicking sound and when I get the other valve cover off I'm going to take a close look to see if I have any cracked rocker springs.

 

[Number4]

I don't think there should be any looseness, let alone 1/4". The tensioners should keep it taut at all times.

 

[SyberTiger]

I don't think there should be any looseness, let alone 1/4". The tensioners should keep it taut at all times.

There's only a chain tensioner on one side of the chain between sprockets. Seems like it makes sense there could be some looseness if the engine is not running on the other side of the chain which has no tensioner. I would assume that when the engine is running the chain is pulled taut and the tensioner picks up the slack. Make sense?

 

[Number4]

Here's an image that best shows there should be no slack on the chain.

 

[SyberTiger]

I'm in process of replacing all the timing chain components....just waiting for the parts to arrive. I figured that after 150K miles it's worth replacing even though I don't have any known problems as I already have the engine partially torn down so might as well.

 

[SyberTiger]

Here is a comparison of the right side tension on the cam sprocket. When the crank sprocket pulls on the chain it is taut but when the crank is not pulling (engine stopped) the sprocket the chain is loose. I took off the valve cover for the left side and so far what I can tell it is taut all the time. I'll probably have the timing chain cover off tomorrow to take a close look to determine if it is "chain stretch" or what. My replacement timing chain kit arrived and I'll be replacing everything: sprockets, chains, tensioners, arms, etc.

 

[SyberTiger]

Houston, we have a problem!

Good thing I opted to go ahead to open the timing chain cover, inspect and replace.

 

[drdoom]

Wow what a mess

 

[drdoom]

Yes good call on that one!

 

[SyberTiger]

The tensioner is underneath on the right side. You need to look down and check the cassette for wear. https://sites.google.com/site/hobbyhintstricksideas/Home/ford-4-6-timing-chain-repair for some pictures of what wear looks like.

Fortunately, even though I had just as much wear on the tension arms I did not observe any of the crud and grinding attached to the chain in those pics. I change the oil pretty religiously every 3,000 miles so maybe that's the difference. I would think that the resin plastic on the tensioner arms and the aluminum itself is much softer than steel, including the bearings therefore, while not good, maybe not as damaging as one would initially think...food for thought.