woojah

I hope the experienced folk on this forum can help me to diagnose a couple of weird sounds coming from my S2000. A couple of Honda dealers are giving me some inconsistent diagnoses of the problem (or none at all in the second case).

The first sound happens on overrun when the revs are falling from around 4000 to 2000 rpm (i.e. decelerating immediately after taking my foot off the gas pedal). I can best describe the sound as a growling or low-pitched duck quacking sound. The sound isn't continuous but happens in sort of intermittent bursts as the revs fall. This only happens when the engine is warmed up. One dealer says it might be a rattle in the CAT, another says it is the rattle of the secondary heat pump and is normal. What are your thoughts?

The other sound happens on start-up after the engine is dead cold. From inside the cabin I can hear a very light tapping sound happening 2 to 3 times a second (sort of like tapping your fingernail on a hard plastic item, but sounds a little "duller" and a little more metallic). I can pinpoint the sound to the engine area and as the engine warms up the tapping "blends in" with the rest of the sound of the engine when idling but can be just about heard if you know what to listen out for. It can only be heard at very low revs - i.e when the engine is idling at 1000 to 1500 rpm. I recently had my valve clearances done and was wondering if this could be the cause?

Thanks in advance - I'd appreciate any words of reassurance that I'm not going mad!

TangoVTEC

You haven't stated which your your S2 is, but if it is an early one:

The first sound is possibly the clutch, there is an issue with early type clutches that causes a buzz (or was more like a chainsaw on mine!) on deceleration from medium-high revs, and only when the engine is warm, mine was worse after 5 minutes of blasting around for example.

The second, regardless of year sounds like the timing chain tensioner, or TCT as it's more commonly known.

Where abouts are you? Maybe a local member can have a listen?

unclefester

In the profile it says 2008 car. Depending on mileage it shouldn't be any of those things so early.

NineBolts

it's not just 2009 cars and from your description it could be the known issue. It could also be completely different causes.

I heard Gaspodes car when he first had the problem and that was a very light metallic rattle (more of a tinkling) when revving between 2-3K out of gear.

Cats and exhaust baffles make similar noises, as do the brake lines knocking on the brown heat shield etc etc.

Details of the car and any Mods?

If you have any chance to get it onto a ramp you should easily be able to tell if the source is the cat or the exhuast, if it does it from cold how long does it do it for? the exhuast gets very hot very quickly, a matter of only a few seconds really.

It's been covered on here that most dealers don't seem to have a clue about the late model engine issues. Have a read of the threads and find on eof the dealers near to you that has dealt with one before and knows of the issue and how to test for it. Honda UK seem to be aware of the issue and have a series of tests that they get the dealer to carry out. For whatever reason they don't seem to like communicating this info to the dealers or the dealerships don't stay abreast of technical updates.

woojah

Yes, it's a 2008 car (what happened to the car and location info under the avatar?!) with just under 12k miles.

No mods.

I've heard the sound of the clutch buzz on you tube, and my growling sounds a little bit quieter and duller than that. But I may run that your suggestion by the dealer next time.

I'm based in Kent if anybody is able to lend an ear!

Laserlady

Where away in Kent ?

GREGSTERWIZ

All S2000's have gearbox (and other) noises

They are very mechanical sounding cars

I think the noise you are describing is probably normal unless it is particularly loud or is getting worse

p800bry

I live in Kent and have heard the dying engine sound that have been affecting the late model engines.I could have a listen for you

cupracing

Mine does the tapping noise when cold, always has. Have done valve clearances on it and it's still the same. When it has fresh oil in it, the sound is more pronounced and as the oil gets older the noise gets quieter. It's literally there for a couple of minutes.. Im starting to believe it's a characteristic. These engines really arent that refined

woojah

Good point, I started noticing the tapping sound after I had the car serviced and oil changed. I'm pretty sure that once the car is full warmed up the tapping sound goes away, but it definitely is there for the first 5 or so minutes.

I definitely agree S2000s are very mechanical sounding - I'm just having trouble in telling whether these abnormal sounds are actually just normal!