so i recently failed emissions and did a bunch of tune-up stuff and finally got the car to pass. That thread is here: https://honda-tech.com/zerothread?id=1677187

Anyway, i changed spark plugs, distributor cap & rotor, oxygen sensor, PCV valve, air filter, and muffler. I sprayed the intake clean as well. I also sprayed some belt dressing inside the timing belt cover, because the belt seemed to be a bit noisy. I couldnt get the cover off, so i sprayed through a tiny opening on the front in hopes of being able to get some on the belt itself, but honestly i could see in there, so im not sure where the belt dressing spray ended up.

Over the course of the past month, this crazy sound started and has gotten steadily worse. Before i did the tune-up there was a tiny bit of noise that i couldnt pinpoint, and my mechanic said it sounded like maybe i needed a new timing belt, BUT he he wasnt sure.

Since then the sound has been getting louder and more pronounced. Take a look and listen here: http://www.youtube.com/watch?v=NKcNlPKelRI

i read up on it (here) and most of the threads said this was the sound of a spun bearing. I am inclined to agree, but was hoping for some expert ears to weigh in. The one reason i dont think its a a spun bearing is that the sound started to be noticeable after i did the tune-up. Is it possible that the timing needs adjustment? Or did i accidentally disconnect something? Could a faulty fuel injector cause the noise? I tried disconnecting each spark plug (one at a time with engine running) and the noise stayed the same. The engine has a proper amount of oil, and as far as i can tell the car was NOT neglected by the prior owner.

so what could it be? any help would be appreciated. BTW- if the video isnt good enough, let me know, i will reshoot it.
Thanx


Modified by D15B666 at 7:50 PM 8/26/2006

 

hey here is part2 of the video (i didnt think you could hear the knocking sound very clearly in the first one):

http://www.youtube.com/watch?v=8BdMXU1siOk


btw- (i think) i have good compression (i havent actually tested it) and the car still moves pretty quickly, NO check engine light, no overheating, no problems. JUST that gdamned noise.


Modified by D15B666 at 9:12 PM 8/26/2006

 

seems like some valve clatter possibly. which could be valve adjustment or timing issue. check on clearences for valves and check timing that would be my first guess. considering you changed the distributor cap i am banking on timing.

 

Valve Lash/Clearance could play a role. Simply take your oil filler cap off and listen inside. I'll bet it'll be louder inside there. Valves are likely out of spec. Pretty easy to fix. If your valve lash is out then you won't have good combustion etc (ie. clearance too small = valve stays open slightly when it should be closed; too large a gap = valve not open fully/long enough)

I had a 240,000 D15B6 (HF) that needed bearings in the bottom-end from 190,000- it's death at 240,012 miles! Ended up throwing two rods through the block. Made a nasty sound but nothing as loud as in your video.

 

did u changed an a/c belt ???? Something like this happend to me,,, it was the tensor hitting with some rod on the bottom...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JUN. &raquo;</TD></TR><TR><TD CLASS="quote">did u changed an a/c belt ???? Something like this happend to me,,, it was the tensor hitting with some rod on the bottom...</TD></TR></TABLE>

nah man, i didnt change that. You know what i think happened? Now that im more sure that it is not a spun bearing, i feel comfortable in saying this:

the car wasnt firing very well before, and after the tune up it probably needed a slight adjustment in timing. But where i screwed up is in using that belt dressing spray. I sprayed too much of, and i think the timing belt STRETCHED. The belt was probably already streched out before, but adding the spray caused it to stretch even further. Anyway, thats my guess for why i have the noise.

Thanks to those who helped to identify the sound, cuz i wasnt sure what the hell it was at first. I appreciate the input fellas. Im gonna try and mess with the timing later today (hopefully) after my friend brings his timing light over, so i will update then.

if the changing the timing doesnt improve the noise, then i will to mess with valve clearances, BUT i have never done that. I read up on it and it sounds easy enough. But i gotta get a feeler gauge first.

ultimately it looks im gonna need to change my timing belt real soon. Im not exactly looking forward to that, cuz i have never done that either. BTW- how much is fair price to pay someone else to do the timing belt? If anyone lives in NOVA and is interested in helping me out, hit me up. I'm willing to pay for the help, but i would like to be involved in the procedure so i can learn how to do it.