Odd noise question

[banzaicars]

Having only had my car 2 weeks I don't know whether this is an issue or not. Now the noise in question (please forgive my description):

It is from the engine and happens when the car is cold.

When I rev it past 2000rpm and allow it to fall to idle, as it passes 2000, 1900, 1800 rpm it makes a kind of rattle that I can only describe as a similar noise to castanets (those things Spanish dancers hold!). The noise isn't there at all either side of these revs.

Forgive my description but the noise isn't offensive or cringe-worthy at all and it totally goes away after about 20 mins of driving - (fully warmed up). It also appears to be more at the top of the engine but to be honest I really can't pin it down at all.

Any help or personal experience is very much appreciated.

The car is a '96 Manual with 53k miles having just had a new clutch and timing belt.

Cheers

Keith

[Lankstarr]

It is not like Hondas to go wrong but I would definitely get a mechanic to look at it. I do know of a similar case and the diagnosis was that the bottom end of the engine was shot. Not wanting to worry you and there may well be a much nicer solution to your knocking and if there is I'm sure you will find it in here. I am certainly no mechanic or expert when it comes to engines but what you describe sounds very familiar. I hop efor your sake I am wrong - I'd wait for some answers from some of the more experienced guys before seeking mechanical assistance.

L*

[Lankstarr]

I would check obvious things that could be rattling at certain resonances first - may be being a bit drastic with my first thoughts!!! :oops:

[Papalazarou]

It might be something as simple as a heatshield on the exhaust. Mine rattle a bit on one side at certain revs.

James.

[sportyking]

The description sounds very like an exhaust baffle/shield/cat rattle to me as well, assuming it happens both parked and moving.

[banzaicars]

The description sounds very like an exhaust baffle/shield/cat rattle to me as well, assuming it happens both parked and moving.

It does happen when driving too but it doesn't sound like a knock, and it does go away once warmed up - do major engine problems only manifest at very specific revs but disappear when warm?. Not sure it is a heatshield as it sounds more from the engine itself.

Obviously a strange one this.

[BrownBear]

Maybe these will help..
http://www.nsxprime.com/forums/showthread.php?t=42256&highlight=vtec+noise

http://www.nsxprime.com/forums/showthread.php?t=40049&highlight=vtec+noise

(I see you already asked - the US guys should be able to help )
http://www.nsxprime.com/forums/showthread.php?t=65416&highlight=engine+noise

Cheers

[banzaicars]

Thanks Brown Bear.

I'm sure the noise is coming from the top of the engine now.

If there is anyone in the Norfolk area with an NSX I would appreciate paying you a visit to listen to yours; this noise may well be normal for all I know. I'm very over protective of my cars.

Regards

Keith