rattle when coming down from a hard rev

[200sx power]

howdy, when I punch the gas rather hard under no load, just sitting in the driveway, there's a pronounced rattle when coming down from the rev. It's not that loud, I can only hear it when the hood is up, but it's there. I was going to file this under the 'when you give your car retarded inputs, it reacts accordingly' file, but Im just curious for a better explanation.

[MagicRat]

Yeah, don't do that, it puts unusual stress (stretches) the connector rods.

In my experience, excess clearances in connector rod bearings, piston pins or excess piston -to-cylinder clearances can exhibit themselves in rattle noises at high revs where the engine is under little or no load.
So, this noise is probably a symptom of a relatively high mileage, well worn engine. It does not mean the engine is worn out, but it is just showing its age, but probably has many miles left in it.

[slideways...]

yep. ^^^ sounds like rod knock to me. a rebuild might be in your near future.

[200sx power]

thanks a ton you guys

[Moppie]

Rather a quick diagnosis with out knowing any real details.

My car makes a pronounced rattle under exactly the same circumstances.
But its just the inner pipe on the dual layer exhaust manifold rattling around because it has broken loose inside (silly thing Honda tried to heat the cat quicker).
There is certainly nothing fatally wrong with the engine.