Car is a 2001 Honda Accord, 4cyl engine (f23), 5spd. manual, 273 000km on the clock!

I noticed the sound about 10-15k km ago.. No loss of power, nothing noticeable except the damn noise..

It's the noise it makes in this video, right when the rpm comes down (after reving), some sort of ratteling



It seems to be coming out from this area;




The lined spot seems to be where it's the loudest.

Now, i made some tests wich all turned negative;

-Removed exhaust manifold heatshield
-Removed Alternator, A/C compressor, PS pump.

Always the samn damn noise. Either cold, warm engine. Always when i apply throttle..

Now, what could this be!?

 

when was the last time the valves were adjusted ?

 

good question, i did not note it sadly, it should have been around 220 000km

 

More importantly, when was the timing belt (and the tensioner) changed out?
It's (The Noise) tough to pick out; what with the loose bottom end and the cam followers requiring adjustment and all.
I'd let the engine cool, remove the exterior accessories drive belt(s) and then start the engine. This would eliminate any of the ancillary systems as being the source (A/C Compressor, Alternator, P/S Pump etc.), and would start us on the path to finding this thing.

P

 

The timing belt (full kit; timing belt, balancer shaft belt, crank/balancer shaft seals, waterpump, both tensioners and springs) were replaced at 220 000km.

I already did remove the alternator/AC compressor/PS pump, and the exhaust manifold heatshield to isolate the noise, it's not coming out from there.


But i wonder what do you mean by loose bottom end and cam followers requiring adjustment? (cam followers aka valve lash adjustment?)

Thanks!

 

Valve lash, yes.

Loose bottom end:
I've a '97 SE with 223,000 on it and it too has a loose Bottom End. It's a condition predicated upon service wear of the connecting rod bearings. It is NOT fatal as long as you keep up on your oil changes.
It's best noted when the engine's fully warmed up.
If you have the car at low speed (or idling it in neutral) and gradually raise and lower the rpm, you can sometimes hear it during the transition from slowing down/picking up.
It's that brief moment where there is no load on the conn rods.
I'm sensitive to it from the number of years i spent listening to these things. You may not be able to pick it out of all the background noise.

I wouldn't worry about it unless your Oil PSI gauge starts heading towards the basement, or you start hearing very discouraging noises from deep inside your engine.

P

 

Connection Rod noise is slow, valve lash noise is twice as fast, that noise is very fast. Timing belts vibrate very fast when loose, I think your problem is the timing belt tension.

 

As I alluded to. Also

P

 

I can always hear the sound when i let go the throttle after reving up (just enough to gain ~1000rpm), at the moment where the engine revs down by itself. I've always maintained it well, doing oil changes every 4000km to 5000km, maximum. Used 5w20 until about 180k km, and then switched to 5w30. Castrol GTX mineral. I even use magnets on my oil filter and oil pan bottom to catch metal shavings, even tough i never seem to have any in my oil when i flush it. Sadly, i dont have an oil pressure gage, only the oil pressure light that is supposed to light on when it's too late.

I'll try giving it a look tomorrow if the weather allows, i'll remove the valve cover to check out the valve lash (clearance), if it's within specs, and if all bolts are still tight. It will allow me to verify the timing belt tension at the same time. Lets hope i get lucky!

I really dont want to remove the crankshaft pulley in order to remove the lower t-belt cover just to check out if everything is in order

Thanks alot for your imput guys!

 

I took the time to remove my valve and timing belt cover (upper one) to check out. Indeed my timing belt was pretty loose compared to usual, so i re-adjusted it. I also checked my valve adjustments, they were all within specs. So were the nuts locking them. Now, i just have to wait a few hours for the gasket maker to dry and i'll see if it fixed the problem...

 

Possibly tensioner springs? I was also suspecting purhaps something as simple as a pulley being torqued to a certian side upon revving, and grinding with something within its perimeter.

 

i did replace the springs and tensioners this summer. The engine didnt have more than 250 000km on it. Sadly i couldnt afford them last year when i did the timing belt job, so i added them later on.

and yes, i drive alot; average 50 000km/year.

 

Well, last sunday i took the time to check out the engine.

The timing belt was kinda slack, so i tightened it up following the shop manual instructions. I also checked the valves lash adjustment, they were all within specs.

I couldnt take off the lower cover to access the whole thing, it will probably be happening this weekend if i can take care of it.

Results;

I let the car warm up in the evening when everything was good to go. Sadly, the little ratteling/buzzing noise was still there. I took the car for a spin (smoothly). It was still doing the noise when i came back. Next day, i go at it again. About 150km later, there is no more noise when the engine is warm coming back from a ride. Go to work, come back. Bang, still the same shiznit. But now i have a new sound, it's been going on since monday night/tuesday i think. Especially noticeable when engine is at operating temp, and i am smoothly accelerating (rolling or neutral)

http://www.youtube.com/watch?v=nFFtT8fIsJM

It's someking of whirling, or humming (im not sure what's the exact word). And as you can hear, the rattle/buzz is still there (at the end of the video)

Seems to be related to the timing belt, but i'm not sure if a component could produce the same sound? What does it make you think of?

 

the one noise sounds like you may have overtightened/ not tightened your timing belt enough.....also select brands of timing belts are just known to be noisy

 

that vaalve lash noise is weired..it comes and go away.i use to have a 90 accord that makes that noise then sold it to good freind.i get to ride in it sometime..he did replace the water pump.lastime i ride in it the noise went away??the accord was sohc..not vtec though.gl

 

100% sure that is timing belt noise. I noticed that the old noise is gone, but the second noise is that of a timing belt too tight.

 

belt too loose the first run, too tight the second run

 

Hey, thanks for the replies!

I did tighten the timing belt according to the specs (auto-adjustment), and after all the things i read, it sounds like something's wrong with my tensioner..

I'll try to take off my lower cover to inspect everything, and maybe take everything apart and start over again this weekend. One thing is wierd, the first time i did my timing belt at 220 000km, everything was fine. Then, when i replaced the tensioners at ~240-250 000km, everything was fine for a while. THEN, i got this noise!

All my parts are from Honda; tensioners + springs, belts, water pump, seals, and the balancer shaft seal retainer. And i DO follow all procedures from my accord factory manual.. Anyone ever had premature failure on those parts, new from the dealer?

I just hope it's nothing (aka easy fix) if not ill need to wait until next tuesday for parts before i can fix it back up!!

 

If anyone is curious about what was the initial problem, here it goes!



I finally found what caused the buzzing noise from video 1; A little part of the exhaust manifold gasket. The round pin in the middle of the circle is loose, and i can easily move that extra piece of the gasket. Tomorrow i will try to cut it off, removing that loose end. I hope it will work! (The noise changed when i pressed that little piece.) I feared it was an exhaust leak too, but it seems to be only this...




Located here;




Tomorrow, i will try to remove the whole timing belt cover to make sure everything is fine under there. I still have that sort of hissing/humming sound in vid 2 from after adjusting the belts.

 

i'm getting the same sound. good info !

 

Omg I think my GSR is making same noise hahahahahahahahahahahaha

good Info!!!