This morning as I was warming up my car, I noticed an odd noise. It sounded like there was a hole in my muffler. I looked under the car, but didn't notice anything so I started driving to work. After getting out of my parking lot, I heard a noise like something clanking under my car. I pulled over and looked under my car and saw nothing. So I popped the hood and immediately noticed my oil cap missing. I looked quickly to see if I could see it, but didn't and looked on the ground but didn't see it anywhere. I then went back to my apartment to call around to see who might have an oil cap. After calling 2 Honda dealers (both didn't have any) I called Pep Boys and found that they did. I rode my Bike over to Pep Boys and picked one up. I then put the new oil cap on and checked the oil. But on my way to work that rattling sound kept up. I haven't been able to figure out what this noise is. It is only heard from inside, it seems to be coming from right under the shiftknob. I know it's probably not easy to say from my story, but I was just wondering if anyone had any idea what this sound could be. I'm taking it to Honda tomorrow morning, but would sleep better with any input anyone might have.

Thanks,
Rice

P.S. The oil level was full and there wasn't a spec of oil anywhere in the engine bay.

 

maybe the oil cap was loose and fell somewhere into the engine bay, and its stuck now. its probably rubbing against a moving metal, and that is probably why there is a noise.

good luck

 

Sounds like the previous oil cap might have fallen down against the firewall near the back of the engine.

 

That's exactly where most of them wind up.. mine did. A bitch to get out but it is possible.

 

Mine fell into the stupid transmission tunnel. Could not get at it from up top or underneath the car. The dealer finally got it out.

 

so why do so many oil caps end up falling off? user error?

 

If you look at your oil cap, you'll see a ring that is inset into the underside of the cap. On some cars, about 75% of the time that the cap is removed, that ring stays on the valve cover. (Mine is one of those.) It is not very visible, especially if you don't expect it to be there, so you go about your business of topping up the oil. If you are lucky, you will not have disturbed the ring at all and the cap will screw on and seat that ring perfectly. If you did disturb it, even a little bit, the ring will not seat and your cap will not screw down tight or all the way. In time, it will vibrate loose and fall off.
Always check for that ring each time you remove it and make sure it is seated completely in the cap before putting it back on. Also, there is the right way and an up-side-down way. It only works one way.

 

thanx everyone. Those are the answers I was hoping to hear. I was just hoping there was no known problems stemming from the missing oil cap. I know there was a post in the UK forum about ppl having their oil cap popping off and that's why I decided the dealer could wait until today. At first I was afraid my car was tampered with but after reading about other ppl's experience I realized it probably came off on it's own. I'll ask the dealer to look for me since I couldn't find it. *cross fingers*

Thanks,
Rice

 

Pretty common problem. Cap loosens, falls off an lands behind engine/above transmission and makes a terrible noise.

FYI, most Honda and Acura oil caps fit the S2000. They all have different part numbers, but its mostly due to minor cosmetic differences and the oil spec that is printed on the cap.

 

I had this happen to me recently. Bought a new cap and now have the buzzing near the firewall. I jacked the car up this weekend, but couldn't find the missing cap. Any ideas on where to find the missing cap? It's driving me nuts. Thanks.