Ringing noise at high RPM

[zack]

So my B16A seems to have a synchro problem when shifting from 2nd to 3rd gear during vtec. Below 5500 it shifts perfectly. Last night i just noticed that occasionally i'll get a high pitched ringing noise come in at about 7k all the way untill i shift. Has this got anything to do with my synchro problem or is this an unrelated problem? It's not all the time, it only happens every now and then...

Any help would be greatly appreciated!

[omgzilla]

Can you describe the ringing noise in a bit more detail?

Is it when the engine is cold/hot?

Noise audible from the front of engine or exhaust?

[zack]

It's hard to explain. It's definitely coming from the engine bay. I hit 8000 rpms today and there wasn't any noise. It was definitely there last night. I'd never rev that high unless the engine was warm. It was strange though, the noise only became apparent at about 7k.

[zco]

engine pinging ? what petrol you using ?

[zack]

BP Ultimate

[zack]

I was just thinking. Normally i fill up once i see the petrol light come on. I always run it all the way down before filling up. But for some reason i still had some V power in there (maybe a quarter tank) and then filled up with BP ultimate. Could that be the cause?

[teh_mechanic]

no that wont cause anything bad.
off topic but - you shouldnt always run the car down til the light comes on.all the dirt n stuff that builds up in the tank sits in the bottom,if your picking up fuel right from the bottom when your tanks almost empty,chances are it will be pretty dirty.

as for the ringing noise,its pretty hard to diagnose over internet,lots of things could be making noise
wouldnt be pinging,that sounds more like a diesel kind of noise,not high pitch

[omgzilla]

Agreed - I would encourage you not to run the tank empty.

Not something silly like a belt slipping? Check the condition of your belts lately?

[zack]

The motor just had a major service 2 days ago...

[teh_mechanic]

maybe they didnt tighten your belts in the service if they needed it.
Check that the belts dont have visible cracks in the surface or look just generally worn.
U should be able to push on the belt and move it a couple of millimetres or so,any more slack on it then that and they will be lose,making a squealing noise sometimes

[zco]

ever heard of a fuel filter ? your fuel pickup line is at the bottom of your tank.. whether or not you drive the tank till empty does not matter. if the dirty shit is at hte bottom of your tank, its gonna be picked up anywaytappets ?

[teh_mechanic]

ever heard of a fuel filter ? your fuel pickup line is at the bottom of your tank.. whether or not you drive the tank till empty does not matter. if the dirty shit is at hte bottom of your tank, its gonna be picked up anywaytappets ?

i understand where you are coming from,the pickup is at the bottom.but if you have all that dirty shit in the bottom mixed with 20L of fuel its diluted and not so bad,compared to the dirty stuff diluted into 2L of fuel when tank is low,a very dirty fuel mixture,sorry to say it but the fuel filter cant filter out everything,especially if its over say 20000kms old,gets pretty dirty by the time its at injectors,which take a microscopic bit of dirt to block them.

but lets keep this on topic

[omgzilla]

tappets ?

If it we're tappet noise it wouldn't be intermittent. They'd be making a racket constantly (given engine temperature and heat expansion etc).

So the noise is only at high RPM but not consistent/intermittent?

Is it a shriek, squeal, whistle, grinding noise?

Coming from front of vehicle? Engine noise or exhaust note?

[zack]

It's definitely form the engine. I've also just noticed that there's a strange noise in idle. It's like a very light tapping noise. Sounds very tinny... Honestly, my motor doesn't sound too good.

[omgzilla]

The tapping noise you're explaining sounds like your tappets (valve lash).

The valve lash should be adjusted every 20,000klms.

DIY here: http://www.ozhonda.com/forum/showthread.php?t=15443

Not sure whether both sounds are related or not though. Did it make the ringing noise before you had it serviced?

Did you have them use any particular engine oil?

I actually adjusted my tappets when I first got my EK4 cause I had a pretty nasty rattling sound coming from the top of the motor. They was far too much clearance on mine. Once they were adjusted correctly it quietened it up a bit but there's still a rattling coming from (we think) the distributor bearing. It comes and goes depending on engine temp. Now that i've lost my license I might pull it apart and have a look-see!

Though mine doesn't make a ringing sound at high rpm - can't really hear it that loudly unless the bonnet is up.