Timing chain help

[RMin280]

Hey guys, a little backstory first, I had been hearing some ticking coming from the engine bay so I adjusted my valve lash. As I was doing my lash and turning the engine over by hand, I noticed a pretty bad clunk or click coming from my timing chain. I thought it might be the tensioner but not really sure how to check that. I tried checking if my chain had stretched but I'm having a little difficulty. Anyone know what's causing this noise? I put a video below in case that helps anyone.  

 

Thanks in advance. 

[Zed Head]

You are turning the engine the right way but you are pushing on the side that should be pulled by the crankshaft sprocket, when you use the camshaft bolt.  Since you're using the camshaft bolt you have to turn the engine backwards.  That will keep the tight side tight.  But it will also run the chain over the tensioner backwards.  

If you're worried use the crank bolt and see if the noise is still there.  Pull down on the tight side. 

And if you get your eyeball in just the right spot I think that you can see the tensioner.  Or use a mirror.

Edited October 12, 2022 by Zed Head
sue does not = use

[RMin280]

I did turn the engine over the other way and it still had the sound, would the noise still happen then? I can try and turn the engine using the crank bolt to see since it's pretty easy for me to do.

[RMin280]

So it is nothing basically, I turned the engine over by the crank bolt and nothing out of the ordinary. Thanks for the help.

Also I just took the car out and I'm still having that loud ticking that I thought was the valve lash. I'm not sure what this could be at this point. @Zed Head you seem to be pretty knowledgeable, any thoughts about this one?

Edited October 13, 2022 by RMin280

[heyitsrama]

I had a weird tick like that once,

 

 

i mean i still got weird ticks, but that one is gone....

Edited October 13, 2022 by heyitsrama

[RMin280]

Thank you! I’ll check the pads tomorrow. How would I be able to tell if there is an issue with the tensioner?

[Racer X]

How many miles on the engine?

As a point of information, the timing chain doesn’t “stretch”. What happens is the pins and rollers wear, resulting in excess play at each pin and roller.

Add that up over the dozens of pins and rollers, and the effective length of the chain increases.

Also, the curved chain guide, and the guide on the tensioner plunger get grooves worn into them as the chain slides over them. 
 

The chain, guides and sprockets are many times better than timing belts and sprockets with regard to overall wear and longevity. An engine with a timing belt will need to have the belt replaced every 100,000 miles or so. And engine with chain driven cam(s) can conceivably go several hundred thousand miles, with little wear, and chains rarely fail like belts, provided proper maintenance is performed (oil changes).

I have seen some very high mileage engines with chain driven camshafts where the wear and ultimate lengthening of the chain caused the chain to wear through the chain guides, and the front cover. It was the resulting oil leakage that brought attention to the problem with the chain. 
 

In your case, the only way to check the wear is to remove the front cover, and examine the curved guide and tensioner plunger. 
 

You can also use a pair of water pump pliers (the kind with curved jaws) to rotate the camshaft back and forth, not enough to rotate the crankshaft, just enough to observe how much play is present in all those pins and rollers on the chain.

 

 

 

 

 

Edited October 13, 2022 by Racer X

[siteunseen]

Shade "woody shrub" way is push the handle of a big screwdriver down between the chain. It should be hard to push down all the way if the tensioner is right. Another way is buy a cheap bore scope that works with your smartphone and have a look.

[Zed Head]

Sometimes an exhaust leak can sound mechanical.

Nissan actually provided a way to monitor chain wear.  The notch and groove.  Some aftermarket sprockets don't have the notch though.

Edited October 13, 2022 by Zed Head
Capital T

[RMin280]

So I pulled the valve cover and all of the lash pads are in place, and I moved the camshaft both ways and there really wasn’t any play. As for the notch on the sprocket, I was looking at that but I’m having difficulty setting it to tdc. I can get both valves on cylinder 1 to be closed and have the bright link on #2, but I have an issue with my dampener. There are quite a few marks on the dampener and I can’t seem to get any of them set at 0° with the valves and bright link set correctly. Is there some other way to set tdc?

[Reptoid Overlords]

12 hours ago, Racer X said:

 An engine with a timing belt will need to have the belt replaced every 100,000 miles or so.

 

 

 

 

 

Our '92 Camry has a timing belt service interval of 60.000 miles.  Miserable job too. 

1 hour ago, RMin280 said:

 

 

1 hour ago, RMin280 said:

but I have an issue with my dampener

These dampeners are notorious for having the rubber portion deteriorate over time causing all sorts of issues observing timing.  You should be able to turn the engine over several times to get the zero mark on the dampener to line up with the cam sprocket markings and have the bright link set on whatever number(usually 1) and have the cam lobes pointing to the "bunny ear" position.  A screwdriver or the oil dip stick lightly inserted in cyl. no. 1 will also give you a visual about TDC, just make sure it's on the compression stroke.

Edited October 13, 2022 by Reptoid Overlords

[RMin280]

@Reptoid Overlords The previous owner of my z put on an aftermarket harmonic dampener, so there are marks on it but not sure which one to use. It has 5 grooves I believe and two red paint marker marks. I can try and keep turning it over to see if it lines up but I was spinning it over quite a bit and couldn't get any of them to line up. The closest they got was the first mark or groove almost lined up with the bottom of the plate that has the degrees marked on it. I'll try and use a screw driver but how would I know if it's exactly tdc? If I'm a little off it can move the notch and not give a good representation of if I need to move my cam.