Loud rattle from under valve cover.

[drb5721]

I have recently stated in another thread that i had a rattle on startup that would go away after about 5-10 seconds. Would be audible slightly as the engine warmed up. Well as of this morning the noise is much more audible. Listen more to it and it sounds more like its coming from cylinder 3 or 4. Pulled the valve cover and i dont see anything out of place. Anything common on the z22 engine specific to certain cylinders?

[Roadster-ka]

Please check valve adjustments and report.

[drb5721]

Guess ill have to let it rattle until hot.

[datzenmike]

Even cold a very loose set valve will be different from the rest.

 

 

 

Is it due for an oil change and what grade of oil do you have in it??? If so, try 15W40 Shell Rotella T4 or Chevron Delo 400 15w40 and a new WIX (not fram) filter. I've heard that the rattle described is a Z series engine's way of saying it needs an oil change.

[drb5721]

Changed the oil when i did the head gasket. Havent driven 1000 miles yet i know. I ran castrol 10w30 and i would NEVER buy a fram oil filter. Currently using purolator oil filter. Going on initial check all valves seem to be similar in play. Maybe even a very slight bit tight.

[datzenmike]

Valve lash can be described as more of a ticking sound. Rattle is usually faster sounding like the timing chain has worn through the covering on the chain guides or perhaps the tensioner.

[drb5721]

With the cover off last night, there was no slack in the chain. I was expecting to see something out of sorts there. Even now with it slightly warm the rattle has gone at idle but can be heard with part throttle around 2000 rpm with no load. Hard to test a stick with a power brake method.

[racerx]

U do know that our Datsuns engine ate louder than today's cars?

[drb5721]

I am aware of that. But i also realize abnormal noises.and this has to qualify as abnormal

[G-Duax]

Since we can't hear what you are hearing, let us know what you find after you dive into it.

Anything else is just a guess on anyone's part.

And even if we could hear it, keep in mind that opinions on a public forum are usually only about 50% correct on a good day.

[drb5721]

I can agree for sure. Trying to upload video of the sound as i type this

[drb5721]

https://streamable.com/2n5y0

[datzenmike]

Set the lash.

 

If it gets quiet when warmed up this is the parts expanding from the heat and reducing the clearance. I think it's 0.012" for intake and exhaust. If they are set correct then this is how it will sound when cold.

[Crashtd420]

https://streamable.com/2n5y0

Almost seems like an exhaust leak too.... I don't know if it's just the video or not but I swear I see little puffs of smoke from the tube connected to the exhaust.....

[datzenmike]

An exhaust leak will be louder under load. Again as parts heat up the clearances will close up so possibly.

[Dolomite]

Almost seems like an exhaust leak too.... I don't know if it's just the video or not but I swear I see little puffs of smoke from the tube connected to the exhaust.....

I’m seeing something too.

[drb5721]

The smoke you are seeing is where oil had dripped down yesterday. 

[racerx]

Sounds like valve adjust. Smoke coming from oil on exhaust manifold?

[drb5721]

Yes. Smoke is coming from where oil spilled on the manifold. I am gonna check valve clearance this evening weather permitting. 

[drb5721]

Quoting datzenmike here, 

Loosen the nut and turn the screw in or out lock the nut again. Intake and exhaust at both set at 0.012". Just slip a feeler gauge between cam lobe and the adjuster.

 

 

Set motor to TDC #1 and set

 

ex. and in. on #1

int. on #2

ex. on #3

 

Turn motor ONE revolution and set

 

ex. on #2

int. on #3

int. and ex. on #4..... done.

 

You would actually measure between adjuster and top side of the valve correct?

[captain720]

I have a video on valve adjust. Yeah you put the gauge between adjuster and valve NOT under the cam.

 

 

 

I would just replace timing chain with new JDM one, but it only takes me a Saturday to replace a chain.

[banzai510(hainz)]

i put a feeler gage inbtween the rockarmpad and thwe cam. 

I  do .006 and .008  but one can bigger .008,.010 or .101 and .012

[racerx]

Write on piece of paper I and e, then x when done

[Crashtd420]

i put a feeler gage inbtween the rockarmpad and thwe cam.

I do .006 and .008 but one can bigger .008,.010 or .101 and .012

I think that's true for L motors but I think the z motors are like captain720 said.....

[datzenmike]

My '84 (Z24) FSM says 0.014" hot for intake and exhaust.