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Discussion Starter #1 (Edited)
Basically, at idle and momentarily at low accelerating RPMs the motor would make a sound like the chain was hitting the guide so that's why I pulled the valve cover. It wasn't a continuous noise, just on idle and these various instances. When the car was started cold it had no noise. It was only when the car warmed up.

Upon inspection, the top guide was perfectly mounted on there. It was not loose at all. I took the top guide off and it had some minor abrasions in the top from the chain.
The timing chain has a little bit of slack in it (granted the tensioner is operated on oil pressure). I took a screwdriver and I poked around on the chain down on the bottom tensioner and it was pretty tight. From the pics, do you think the chain should look like that?

I did not take off the front cover to physically inspect the tensioner because I am a noob and I don't have the tools to take belts off. Hopefully, this will get rid of the momentary rattle.

Do you think a tensioner would cause the slack to go away between the two gears. Basically when I take a wrench and turn the intake cam gear counterclockwise the slack goes away. Is there a possiblility the chain is stretched?

Currently my plan is just to put it back together and see if the rattle persists. Next, would probably be the tensioner (if that helps). The final step would probably just be to replace the whole deal (chain, tensioner, guides).

SR20DET redtop, 60k miles on the clock.


 

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I'm also curious about this. I've got mine out and on an engine stand and it looks identical. Same thing for me...slack only happens at some points on the rotation while cranking it by hand.

Anyone know if this is normal?
 

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It shouldnt be like that. From my experience when I removed cams and put them back in. The chain was dead on tight with almost no slack. There wasnt slack up top, on there should be slack between the crank sprocket and the right cam sprockert. That is where the tensioner removes the slack under oil pressure.
 

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Hmmm...mine was like that when I originally pulled the vc. I read somewhere that you're supposed to soak the tensioner in oil to give it some pressure while it's out? I wonder if the tensioner went bad when the motor was shipped, since there was no oil in it. Can I soak it now and build some pressure in it, or is a new tensioner in order? It's a W10 motor, so I'm assuming the tensioner should be one of the newer, beefier versions. I also read somewhere that Avenirs tend to have more slack like this (although the pics above are obviously from a RWD motor) at tdc and bdc. So yeah...now I don't know what to think.
 

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It should be tighter than that, but it shouldnt be too tight.

I would try a new tensioner, a new chain is a good idea but you need to know what you are doing to change it. The chains do stretch over time.
 

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SR20DE stock G20 p10 highport
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Hoping someone who knows about timing chain topics is still around on here, specifically the slack-side timing chain guide and bolt.
I also have slack between the cam sprockets. I replaced my tensioner and want to replace the guides, but I saw this same slack between the cam sprockets and wondered if it was normal given the tensioner is a hydraulic tensioner and there was currently no oil pressure in the engine.
I called jimwolftechnologies and a "technician" told me this slack is normal and that the oil pressure will cause the tensioner to extend and push more on the slack-side guide once the engine is running. He also suggested before cranking the engine, to pull the fuel filter fuse and than crank the engine. This way just the stater is moving the engine without any real rpms or combustion behind the pistons. He said to do this until the oil pressure light on the dash goes away.

I recently replace the timing chain tensioner and removed the chain because I want to replace the older guides with the later guides. I am aware that in the later SR20's, Nissan changed the guide and the bolt, which make think it was for some specific reason.
When I look at the slack-side guide (the curved one), I see that the guide moves laterally on the bolt and it seems concerning.
Front to back is to be expected, but there is also horizontal movement at the pivot bolt. I am thinking this extra movement may have put more stress on the tensioner and caused it to fail. Not really sure about that, which is why I wanted to ask here.
I've tried to loosen this bolt, but it will not turn at all, loosen or tighten. Somehow, the Allen hole became rounded out, previously, so I pounded a 1/4 inch bit into the bolt's rounded-out Allen hex and used an impact driver to try to loosen the bolt but was unsuccessful.
The bit does not spin or move at all when I attempt to loosen the bolt, which is good, but the bolt won't budge.
Anyone run int this bolt not wanting to budge?

Should I be concerned about the horizontal movement of the guide at the pivot point on the bolt?
 

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SR20DE stock G20 p10 highport
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I want to replace the guides and bolts, but I am not sure if it is possible given the bolt will not budge.
 

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It shouldnt be like that. From my experience when I removed cams and put them back in. The chain was dead on tight with almost no slack. There wasnt slack up top, on there should be slack between the crank sprocket and the right cam sprockert. That is where the tensioner removes the slack under oil pressure.
Check out this thread that says slack between the cam sprockets at TDC is normal. --------> CHAIN SLACK BETWEEN CAM SPROCKETS
 
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