The valves are adjusted by shims. ( 1.6 NOT 2.0)
You basically measure the clearance with feeler gauges and record.
Take shim out and buy another with the correct thickness.
If you cant see the marking OR the shim is mechanically worn, measure with a micrometer in the worn part not original thickness.
There is a table in the FSM.
The FSM says to use a tool to hold down the valve and slide out the shim. This is the same as Toyota method.
I have done this on a Jaguar by removing the cam, much more work vs buying or renting the tool or improvising.

 

Mine are clicking a bit too, but I'm not bothered enough by it to want to adjust the shims. Is there any danger in not doing anything about it (other than more clicking)?

 

The spec is wide, if you are worried about it check the clearances (hot) and if they are in spec don't worry !!! At 0.019 they will tap !!!

 

When is valve adjustment *really* necessary?

I have almost 95K on my engine, and I have been thinking of letting the dealership do it.

Why go to that expense? They have special tools, etc, and they have to stand by their work. My Haynes manual recommends not trying to do the adjustment yourself because the shims & everything are kind of hard to mess with.

BUT: I'm not actually sure my car needs it.

Like, I'd be getting some rattling & so forth under hard acceleration--right? Or my mileage might fall off, or it would chug, or I might have a visible exhaust trail or flunk the emissions test?

None of these things have happened, and if it ain't broke, you know what the man says!

 

I have more miles than you and have no intention of adjusting the valves unless there is a loud enough taping, then i will check the gap before messing with it.
Since Nissan doesn't tell us anything about this as a regular maintenance item I don't see it’s a problem
FYI for my 64 / 67 Jag, Jaguar says to check the gap every 60,000 miles. And the standard gap was small, excuse me if I don't remember exactly but .006 and 0.010 come to mind.

Nissan says the gap spec is 0.008 to 0.019 intake and 0.012 to 0.023 exhaust
If you are on the larger end of this spec I think you will hear it !!!

 

need help just put a new tensioner on it now it rattle when hot, guess need new shims for the valves, are they solid liffter are hydraulic valves

 

The rattling may be in the chain assembly caused by a failing tensioner. When you installed the new tensioner, was there a lot of sludge in the oil feed hole; if so, the sludge could have worked it's way into the tensioner causing failure.

If you have a GA16DE engine, it uses solid lifters. If it's an SR20DE, then it uses hydraulic lifters.

 

It's simple to check valve clearances, I checked mine and they were all perfect, but then I might have accidentally checked it when it was cold and not warm like it's supposed to be, I can't remember.

Due to a really loud chain rubbing sound, I replaced the upper tensioner with a cheap Autozone S.A Gear brand and the engine got louder. Found out I wasn't the only one, and got a genuine Nissan tensioner. It wasn't anywhere as loud as the S.A Gear tensioner, but the chain rubbing noise was still there. I just recently did an entire timing chain job and discovered the problem, it was that stupid cheap plastic lower right guide. The bottom half broke and that loud sound was the chain rubbing against the loose plastic guide.

The engine definitely doesn't sound as bad as it did, but it's still noisy as hell. It definitely sounds like a valve/valves. I'm thinking about buying a compression tester so I can see what state my valves are in.