Hey guys

About 2 weeks ago when i pulled up at home after a short drive i noticed a bit of a high pitched whirring noise coming from the engine bay of my car. i thought it was weird, turned the car off and back on and it went away. It then started to come back, but intermittantly- the only time you can hear the noise is when the car is still (prolly does it while moving i guess but it is just drowned out by other noises) and so i noticed it pulling up at lights etc at first not all the time but now it does it whenever the car is sitting still once warm. it doesnt make the noise when its cold.

So the next thing i did was start the car without the belt on to eliminate those things (alt, ps pump etc) and the noise stayed. Soo now my next problem is trying to figure out where else the noise could come from. It really is hard to pick out exactly which area but it does seem rather loud whilst under the car around the crank- but im not sure if the crank/HB can make this sort of noise like does it have bearings?? (ps it has also been leaking oil around the crank recently) I guess it would make sense if its possible because the whirring does sound like something rotational- not an air leak sorta thing.

okay so here are the key factors!

NOISE:
- Rotational whirring sound moves up and down with lower revs (below 2000rpm) whilst car is stationary- could possibly be making the noise in all revs its just i cant hear it over everything else!

- Continues to make noise with belt off

- Doesnt make noise when cold

- Slowly getting worse each drive basically

- Quite loud when under the car- crank/harmonic balancer maybe??

What do you think because i really have no clue where to go from here!

Thanks heaps for any help!

Dame

More than likely its the timing chain.

ohh yeah the timing chain wouldnt be more or a rattling noise would it? because this noise is quite high pitched- sam sorta sound as a stuffed bearing

sure its not the cat?? mine made that "whirring" noise once i replaced it no more whirring noise???? didnt do it when cold only hot. was reqally loud to so i thought it was from the engine but nope

As above, more than likely its the timing chain or guide.

In my case it was the Aux shaft bolts that came loose breaking the guide and forcing it through the timing cover.

snapped plastic chain guide

hi
check your dizzy isnt starting to seize?
ive had a dizzy that was tight and was starting to seize and it made a whirring noise because it was putting strain on the aux shaft and cam chain...
or cam chain guide broken and has wedged itself somewhere??

or a posable noisy oil pump in your transmision ??(assuming its auto)??

The timing chains dont just come loose and rattle. I had the same whistle noise and it was the timing chain running over worn guides. I just bought a kit which is basically everything including the tensioner. Noise gone. For a quick check remove the oil filler cap and have a listen.

Didnt you install a cam not too long ago in the xr?
Maybe its noisy because of the extra load on the valve train now.

was thinking about that....

did you reset the tensioner when swapping cams, or did you try keeping tension on the chain/cam gear instead?

if its the latter, then its possible the tensioner sprung out & overtightened the chain causing guides to snap, or aux shaft probs etc

but its all guessing until you have a look

yep i did put a cam in not to long ago and we did reset the tensioner.

i removed the filler cap while it was makin the noise and stuck my ear over it, to be honest it didnt sound like it was coming from in there. ill have to take the rocker off though and get the torch into it. how many plastic chain guides are there?
if it does turn out to be a guide is it a big job to replace them and where do i get a kit with everything in it??

cheers!

get the longest, biggest screw driver you can find and put the big end on your ear and start pointing the small end around the engine bay (contacting different points) you will soon find where it's coming from.

i over tensioned my chain once it didn't sound real nice, best description would be ultimate load and friction. loosened it off and had rattle re-adjusted and no dramas.

and on the dampners i took my last engine apart (C.O.D: cracked number 1 compression ring caused by detonation caused by blocked cat)
and the bottom tensioner had been sitting in the sump for quite some time and the chain had worn in it's own relief into the timing case and it still wasn't audibly evident.

ok well it turns out that it is the thrust bearing!!

But its got me stumped because it not the usual TB problem because the noise doesnt go away when you clutch it, it only goes away when ya get your foot in behind the clutch pedal and pull it towards you which was just pure luck that my dad tried doing that!

What does this mean, like i cant quite get my head around why it has done what it has.
its a new thrust bearing too, only put the new clutch kit in about 2-3 months ago!

well at least its not a death rattle from your donk

Could be the spigot bearing, did you replace that?
Was the pressure plate new?