Tried a search but couldn't find exactly what I was looking for.

I noticed today that I have a weird nasty sounding knock only if I accidentally labour the engine when pulling away without enough revs for instance, so they drop off as the clutch is pulled out just before stalling.

It will tap/knock. Goes away as soon as I dip the clutch and I haven't noticed any problems otherwise.

Obviously I try not to let the revs drop and labour the engine so it won't do it!

Any ideas, any cause for concern??

Many Thanks folks

 

ive had this happen to me sometimes when im in traffic i dont give it enough gas and let the revs go too low it sounds like a knock for a sec but as soon as i push the clutch the engine recovers and everything is fine. its happened a few times and it doesnt seem to have had a bad affect. that being said i would recommend trying to avoid this as noises that sound that bad usually are.
hopefully someone will chime in as to whats actually going on inside when this happens. you should be fine though.

 

You're loading the engine and drive train enough to make everything nearly stop under load, and it causes a "shudder". Normal in the situation you describe and most certainly a bad idea as it strains the bearings on the bottom end and the rods themselves.

 

With most cars I've owned in the past I could rev the engine to 2000 - 2500 RPMs without lugging the engine to launch from a stop. Not so with the S2000. You need to be around 3000 RPMs or higher. And if it's really hot outside and/or you're carrying a lot of extra weight (passenger, heavy luggage, etc.) ya gotta give it even more.

 

Even worse on full lock too