Good day,

I am from South Africa and own a 2008 s2000 f20c2. (South Africa never got the f22c)

I have a K&N FIPK installed, been installed for about 2 years now.

Mileage on car is ~42000km(~26250 miles).

Engine is making a noise as if the serpentine belt is loose.(similar to that of a bicycle coasting noise but not as loud).
I can't hear the noise inside the cabin, can only be heard while standing next to the hood. If you open up the hood, the noise is more evident.
I can only hear the noise at idle.

I can't really take a sound clip, as with all the other noises from the engine you can't really hear it.

It did make this noise before, but that was as a result of a stretched serpentine belt.

The indicator on the pulley tensioner, indicated that the belt wasn't loose.

The stealership recommended I change out the entire belt tensioner and fit a new belt.

I have changed the belt and entire tensioner with all honda parts, yet the noise still persists.

While the belt was off, I checked the other pulleys, and there was nothing out of place, all looked and moved as they should.
I don't want to start the car with the belt off, as the noise would be drowned out by the high revs and the air pump being turned on.

I have changed the oil and oil filter, noise still persists.(I used castrol magnatec professional A3 5w30 and honda oil filter)

My tct is fine, I changed it out for a ballade sport tct, noise was still there, put the old oem tct back in, same noise.

The Stealership used a stethoscope, and says the noise is not coming from the inside the engine, nor is it coming from the other pulleys, and that I shouldn't worry about it.

Apart from the noise, engine behaves as it normally does.

Has anyone experienced something like this or any idea as to what the issue could be?

Next step is to set the valve clearance, which was done like 8000km(5000 miles) ago, reason for this, is so I can inspect the actual timing chain at the same time.

Thanks in advance for the help.

Nitesh.

 

Here's my suggestion:

With a cold engine remove the serpentine belt and start the car. It won't do any harm as long as you run it do 30 seconds or so. If the sound goes away, you know it's coming from the belt or the pulleys it drives.

While it's off, spin the idler pulley and tensioner pulleys. If they have any wobble or grind, replace them.

Put the belt back on, start the car and take a small bar of soap and CAREFULLY rub it against the edges and the fins of the serpentine belt. If soaping the belt doesn't get rid of the squeak temporarily the problem is coming from somewhere else.

I say CAREFULLY because this is very dangerous. Alternatively you could put a little dish soap on a rag attached to a stick to keep your fingers away from the engine. I used that soap bar trick years ago with easier-to-access engines and it works like a charm.