9KEVERYDAY

I have searched and searched and hadn't found any answer involved more than the TCT or valve adjustment. I'm pretty familiar with noises and sounds with cars, at least the basic ones. But this one has me puzzled. Think of the sound that is made when you come to a stop in a car with ceramic brake pads with light surface rust on the rotors, the real high pitched squeal, but not as aggressive or ear piercing. I have an 03 S2000 76K miles. It doesn't really matter the rev range or how hard I am on the throttle. I have noticed it more lately after a light/hard pull, leaving it in gear, and letting off the throttle. While the rpms fall without my touching of the brakes, the noise will occur. It isn't consistent. So one time at a certain rpm say 5K it will do it but the next time, it may do it throughout VTEC. It uses a mild amount of oil per the previous owner, like maybe half to 2/3 of a quart of oil between oil changes. Does any of this help you to get an idea where I should look further? Or just do a valve adjustment to see what happens from there? The valve adjustment is my next step. I have already purchased the AP2 Retainers to install but thought It be a good idea to do the adjustment first for practice as well as to see if that would fix the noise.

Service info:
The previous owner (2nd owner) has owned it since it was 8 months and 8k miles young. He said he kept up on the maintenance. As I got further into the car after purchase, I replaced the brake fluid(piss yellow), clutch master cylinder fluid (grayish/black), trans fluid(dark yellow), Rear diff fluid (dark). I just did an oil change today and installed a honda oem filter for the S2000. The noise is still there. Previous filter was a pennzoil. I put in Castrol 5W-30 "High Mileage" full synthetic. I have replaced the cabin filter, air filter, pcv valve, cleaned the throttle body, used the seafoam spray in intake cleaner that makes the car blow a lot of smoke in the back, put in a can of seafoam into a nearly full tank, changed spark plugs with oem honda plugs. Just to let you know what I have done since purchasing the vehicle and what hadn't been performed by the previous owner.

windhund116

How old is the engine's accessory belt?

9KEVERYDAY

I have no clue so I would guess based on other maintenance being neglected, probably too old. Do you think the belt could make that noise?? It doesn't sound anything like a belt that I've heard in the past.

kukudm

When the noise happens, if you depress the clutch, will you still hear it?

9KEVERYDAY

Great Idea, I will do that tonight and see what happens. Hopefully I can catch it in time because it happens so fast. If I am sitting at a stop clutch depressed, or I am in neutral, the sound cannot be heard on idle or even revving the engine. I can only hear it when I am actually driving.

Edit:
OK, I figured out I can get the RPMS up to about 6-7K let off the throttle and the noise will happen as the rpms fall while I am in gear. Granted, the noise happens quickly and as soon as I hear the noise, I push the clutch in, the noise goes away. Do you think it could have to do with being under load?

9KEVERYDAY

Per the previous owner, the clutch has been replaced and the front brake pads have also been replaced. The front pads are Fisher brand pads, I recognize the markings on the pads. Judging by this, I would assume he didn't spend a lot on a new clutch either. Again, just a guess/assumption.

Chuck S

Belt squeal is the first suspect. The belt will stretch and slip (which causes a squeal) over time and probably due to age as well.

Mine was not slipping/squealing but it was stretched so I replaced mine Sunday morning (still in my PJs, it's that simple). A tad over 50K miles and the belt was stretched beyond the scale on the tensioner:



10 minutes work (7 minutes to get the right socket) and the new OEM belt was on.



Proper belt:



-- Chuck

9KEVERYDAY

Thank you for the info Chuck. I ordered an OEM Honda belt, I will put that on tomorrow and will update the thread then. Thanks again

Car Analogy

Be sure to check both pullys while belt is off (idler and tensioner, the smooth omes without grooves). They should sping quiet, and feel smooth. If not, replace the bearings (or the whole pully, but bearing only is way cheaper). There is a pully bearing diy. Both pullys use same bearing, which you can get from Amazon.

In fact, if you hadn't ordered the belt yet, I would have advised remove belt, then try to reproduce noise. If it goes away, its some combo of belt and or pullys (or something else belt driven, like water pump or ac compressor). If noise still there with belt removed, its none of these.

Obviously dont run car for long with belt removed, dont want to overheat engine.

Sent from my SM-G920P using IB AutoGroup

9KEVERYDAY

I will check on the bearing while I am in there but the noise that I am hearing doesn't sound anything like a belt squeel or any sort of rubber noise. It has more of a metallic resonance to it. I checked a few of my exhaust shield bolts during lunch and those are all tight and no rattle when I would bang on them for any sort of noise.