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strange noise from alternator
Posted: Thu Oct 18, 2007 11:04 pm
by j-top paj
lately i have been hearing a weird noise whilst driving..
it only happens when im labouring the engine between 1800rpm and 2200rpm.
its not restricted to RPM as i need to be in a too higher gear for it to do it..
it makes a sound like a cricket or cicada.
the reason i think its the alternator is because as soon as i back off the accelerator it disapears immediatley..
an ideas?
Posted: Fri Oct 19, 2007 9:40 pm
by macca81
bearing on its way out... the torque of the engine may be puling the belt that little bit harder causing the noise to be noticeable... the same thing happend to mine about 3 nights ago... gradualy got worse till i was worried to drive it untill i worked out what it was
Posted: Fri Oct 19, 2007 11:24 pm
by j-top paj
but why does the noise only happen when im labouring the engine?
its really got me stuffed as to what it is
Posted: Sat Oct 20, 2007 8:51 am
by -Scott-
Is your fan engine driven or electric?
Dodgy engine mounts could allow the engine to move far enough under load so the fan starts to his something?
Posted: Sat Oct 20, 2007 9:48 am
by GQ Bear
My GQ does similar thing, whistle noise at 2200RPM. Has been doing this for some time now. Accelerate beyond 2200 and whistles, back off or change gear and whistles at 2200 again???
Posted: Sat Oct 20, 2007 12:09 pm
by its aford not a nissan
hmmm turbo?
leaky exaust?
Posted: Sat Oct 20, 2007 5:22 pm
by macca81
j-top paj wrote:but why does the noise only happen when im labouring the engine?
its really got me stuffed as to what it is
-scott- wrote:Dodgy engine mounts could allow the engine to move far enough under load so the fan starts to his something?
i was thinking something like that, cept that rather than the engine moving, the pullywheel would just start pulling harder, and pulling the belt wheel on the alt so its not sitting perfectly straight. when its not under load then the bet wheel on the alt is just spinning nicely... it would be more noticable if the belt isnt tensioned as much as it should be, like mine was. mine started in the same way, only under load
Posted: Sat Oct 20, 2007 8:00 pm
by chimpboy
If it only happens when the engine is working hard, then I can't tihnk of any reason why you'd narrow it down to the alternator of all things.
Posted: Sat Oct 20, 2007 9:12 pm
by macca81
chimpboy wrote:If it only happens when the engine is working hard, then I can't tihnk of any reason why you'd narrow it down to the alternator of all things.
i would never have thought it to be the alt on mine either, if it wasnt for the fact i found sparks comming out the front of it coz the bearings were compleatly gone
it may not be his alt, but i cant think of any reason why he can cross it off the list untill he checks.
on that note, take your belts off and see if it still does it. dont run it for to long thoe cause your water pump wont be working...
Posted: Sun Oct 21, 2007 7:41 pm
by want33s
j-top paj wrote:but why does the noise only happen when im labouring the engine?
its really got me stuffed as to what it is
This noise isn't 'pinging' is it? check the timing.
Posted: Mon Oct 22, 2007 10:29 am
by j-top paj
-Scott- wrote:Is your fan engine driven or electric?
Dodgy engine mounts could allow the engine to move far enough under load so the fan starts to his something?
got both, but the thermos dont kick in untill its VERY hot
the clutch fan has plenty of room to move so it cant be that.
the weird thing is it stops at 2200rpm and i can make it stop by backing off the accelerator a bit.
Posted: Mon Oct 22, 2007 10:31 am
by j-top paj
its aford not a nissan wrote:hmmm turbo?
not yet
leaky exaust?
the manifold is leaking but thats a different noise i have to fix
Posted: Mon Oct 22, 2007 10:34 am
by j-top paj
macca81 wrote:j-top paj wrote:but why does the noise only happen when im labouring the engine?
its really got me stuffed as to what it is
-scott- wrote:Dodgy engine mounts could allow the engine to move far enough under load so the fan starts to his something?
i was thinking something like that, cept that rather than the engine moving, the pullywheel would just start pulling harder, and pulling the belt wheel on the alt so its not sitting perfectly straight. when its not under load then the bet wheel on the alt is just spinning nicely... it would be more noticable if the belt isnt tensioned as much as it should be, like mine was. mine started in the same way, only under load
il re-adjust the alternator belts, the only problem is it has 2 belts and they arent identical.
Posted: Mon Oct 22, 2007 10:38 am
by j-top paj
chimpboy wrote:If it only happens when the engine is working hard, then I can't tihnk of any reason why you'd narrow it down to the alternator of all things.
it sounds electrical
nah seriously but, it sounds louder on the drivers side than the passengers side
Posted: Mon Oct 22, 2007 10:42 am
by j-top paj
macca81 wrote:
on that note, take your belts off and see if it still does it. dont run it for to long thoe cause your water pump wont be working...
il take one of at a time and see if it does it.
aircon shouldnt make a difference i dont think (as long as the aircon is of the pump is disengaged)
the power steer i need (drove with a broken belt from 100ks out of grafton once and never again)
that just leaves the two alternator belts.
now i just need to find a free day to do all this
Posted: Mon Oct 22, 2007 10:43 am
by j-top paj
want33s wrote:j-top paj wrote:but why does the noise only happen when im labouring the engine?
its really got me stuffed as to what it is
This noise isn't 'pinging' is it? check the timing.
definatley not pinging. i check my timing regularly