Hi all
Just a question.
I have noticed the following:
Driven the Datsun for some time and then stop at the shop to buy something.
When I come back and start it up to drive home there is a rattle of about 2 to 3 seconds. After that it is dead quiet.
My dad said I must not rev it when it does it, just let it idle until it goes away.
He said it is the warm oil that is now draining quicker away from the timing chain tentioner that just needs to repreasurize the tensioner to make the chain quiet and working normal again.
Are you guys also experiencing it?
What my dad told me makes sense, just wanted to hear if you guys are experiencing similar on your cars.

Hi,Just
Is it really a sound from the engine inside?
Are a gearbox and a differential all right?

I've never heard such a sound, not with the A-series. It is common with overhead cam engines, even other Nissan engines.

I strongly suspect the cause is something else.

It is true, when the oil gets too hot the timing chain makes this noise but only when the engine is overheating, oil is not ok or your timing chain and tentioner are not ok, i have experienced this a couple of times. First be sure that your thermostat is ok and your engine is reaching normal operating temperature, because if it's not what happen is that the mixture is not burned complitly and the resting gas ends up in your oil, and this will cause this problem, obviously change the oil and filter, check your oil pressure and if the sound doesn't disapear then change the timing chain.

Normally, when the engine is off, the timing chain tensioner is held against the chain by a spring inside the tensioners plunger [piston] At startup, this is usually enough to prevent any noise at idle untill the oil pressure comes up enough to hold it there.

I have seen two instances where this spring was broken inside the plunger, & so on startup, the plunger was allowed to be pushed back down it's bore & the chain gave a little rattle untill the oil pressure kicked in & all was well. Hot oil bleeds from the plunger more readily than cold oil.
It is possible that this is what has happened here.

If the chain, the sprockets, & the chain guides are very badly worn, then I guess that it is possible that this could also be the problem, but this engine was relatively recently overhauled, so I doubt that this would be the cause.

To fix it usually involves engine removal to allow oil pan removal which then allows timing case removal etc. This is thought by many to be more work than is warranted for a broken tensioner spring.

I agree with eveything dodgeman said apart from the pulling the engine part. You can pull the sump off and out quite easily with the engine still in the bay as long as you take the swaybar off. I did it in like 15mins. Much easier than taking the whole engine out just ot change the chain and tensioner.

it problily is just as Dodgeman stated, but you can check for a stretched chain by taking the dizzy cap off put a wrench on the crank bolt and then turn the crank forward to place tension on the chain and note the position of the rotor. then turn the crank bacwards, on a good chain the rotor will follow instantly with the crank movement, but if it is bad there will be a delay of movement of the rotor.