weird engine noise! advice opinions please.

[riceburner]

Ok so i got the harmonic shit all done, new keyway, different (uncracked) front pully, different cam pulley, new oil seal and new timing belt and tensioner bearing.

All good in that area.

But i still have this noise its gonna kill me i can see it coming.

How can i describe it, its like wind howling thru a small gap in a window, or a Owl hooting with a slight shuttering affect, can only feel it very slightly thru the car, actually to the point where i think i was so dam tired i was probably imaging the vibrations. Definately no knocking and definately not a high pitch sqeal.

It comes and goes at idle say every 20-30secs, it will go from no noise at all to and slowly get louder till it stops. The noise gets a slightly higher pitch whilst driving till around 25003000-rpm. Then it doesnt re-appear till rpm drops again.

Now i know it isnt the water pump, or clutch in the fan and it isnt the alternator. I left the belt off for a few moments to check those items, they werent moving but the noise prevealed.

So any ideas, experiences with this noise, places to start looking, any suggestion of places to look and listen.

Ill have another attack tomoz after work.

[slide86]

vacumn leak?
have you used a screwdriver or stethascope to try and pinpoint the noise?
do you have to have the bonnet up to hear it?
4age?

[riceburner]

Sorry gang i had 50 millions bloody kids hanging off me at time of print.

Yes 4age JDM rwd.

I did use a screw driver quickly and couldnt really establish anything.

When i get time i will endeavour a more thorough search but i am mearly looking for locations to listen or if anyone had experience with a noise like mine.

Fairly simple description but its the best i can do.

[jdmcoupe]

belts tight enough and did u use the right belts

[riceburner]

Yes and yes

Well as good as i think they are meant to be.

But yes all seems fine there.

I which i had a better way to descibe it, ill see if i can get a rough location of the source of noise. That'll narrow it downa little.

Learning more and more as i plod along.

I would do it now but its like -1,000,000 deg outside.

[mikewestphoto]

I once put someone else's big port throttle body on my big port and it made a horrible, loud squealing sound at idle and we shut it off and didn't bother revving it. I still don't know what caused that sound but my throttle body on his engine was fine. Mine makes no noises on mine and his never makes any noises on his.

It might be something to check.

My car's got a high pitch noise at about 10% throttle, usually between 2300 to 3000rpm. Is this something similar to what you are describing? I don't have a noise like this at idle though.

[riceburner]

Thanks Ken ill have a look at that also. I havent changed my throttle body and i never have. And this motor has been running fun until the keyway let loose.

I have read on club4ag that some folks have had TVIS problems that made there enfgines sound weird.

The joys of fault finding

[pebbles]

my 5k has a high pitch noise at about 10 percent throttle aswell, its annoying because its at about the throttle it takes to put along at 60 in 4th gear, its like realy high pitch, my dad cant hear it, but my mates can coz we're young

[mikewestphoto]

Yeah, that sounds just like my noise but you don't have tvis so I'm thinking it's all vacuum related(or broken tvis). I think the fact that it goes away at a certain rpm while maintaining the same throttle has something to do with the vacuum through tb/plenum.

Also, I'm pretty sure it's in the intake somewhere as I have replaced the long motor in my car and both engines had the noise.

[slide86]

noy leaking from the booster or somewhere like that.

to eliminate a vacumn leak, use some carby clean and spray around possible leak areas.

if there is a leak, the engine will change pitch and run a bit different for a second or two