Terrible Squealing

[ova50]

I have replaced the Belt tensioner, idler pulley & the pivot arm, the nylon bushes in the tensioner looked a bit suspect.
Prior to changing the Tensioner, the vehicle would develop a bad squealing sound when accelerating and mostly only when going uphill, under load.
It would start to happen at around the 1800-2000rpm. If I eased of the throttle it stopped.

Last evening I took it for a drive and the squealing is still there but now it only starts to happen from around the 3000rpm mark,
and again only when going up hill, and under load, and as usual, as soon as I back of the throttle it goes away.

I drove the vehicle uphill on a narrow winding road with rock ledges either side.
It appears that it is coming from the front passengers side of the vehicle.

Have posted it here: https://youtu.be/pQlCyxMwLHc
Any suggestions at to what it may be.


(also found another problem which I will post later )

[Winnie]

Have you checked for any boost leaks? Tighten all the air intake clamps and see how you go.

[threedogs]

still , very common on CRD think either the
egr piping is split or the intake maniflod is warped.
check bolts for correct tightness

[ova50]

Have checked all the hoses etc when I was doing the tensioner.
The boost showing on the Scan Gauge reads what it usually does.
It has not lost any power.
The Egr pipe was replaced around 2 years back and seems to be ok.
The manifold was removed and machined around the same time and does not appear to have any leaks.
You would swear blind the belt was slipping over something that is seizing on and off when under load.

[threedogs]

is there anyone there to help you check where the noise is coming from
OK had a listen check the pulley on your alternator,
to me it sounds like a dry bearing
Mine seized and snapped the shaft

EDIT::: release the tension on the belt and spin the alternator pulley by hand

[Hodge]

Just watched the video and that cannot be a boost leak or air. That screech is mechanical imo. Notice how it's either on or off it doesn't vary in volume or pitch.

[ova50]

It doesn't do it when free revving. Only under a load at the revs I mentioned.

I was just talking to the old guy next door who previously owned a Navara. He tells me he had a similar problem that started with a ticking sound and eventuated into a squeal. He said the Navara had a weird clutch set up on the alternator that was causing the problem.

We had a look on the Patrol and when the engine is running everything seems ok, however when the engine is switched off the belt and the pulley stops spinning, but the internals of the alternator still spins for a couple of seconds. ?????????

[ova50]

Just watched the video and that cannot be a boost leak or air. That screech is mechanical imo. Notice how it's either on or off it doesn't vary in volume or pitch.

The video was spliced together from 6 different ones the wife and I made last night. We can hear it start off faintly ( a bit hard to hear on the video, also had to edit it to cut out the wife swearing)and then it screams its head off.

The on and off sound was because I was accelerating up some very windy hills and had to back off for the tight corners. As soon as I come off the throttle it would stop until I accelerated again.

[threedogs]

Thats what happened to mine just a slight ticking sound that went away with a few revs,
my mates and I all thought just water on the belt and not to worry, only a very small noise
you wouldnt think twice of it. Then on the way home my mate yelled that the temp was rising
{great co-driver imo] so I shut it off straight away lifted the bonnet and saw the end of the alternator had snapped off.
Thats where my money would be with out seeing it in the flesh, alternator pulley/clutch bearing

As I suggested earlier take the tension off the belt and spin the alternator pully by hand.
If only to eliminate it from the equation

[the evil twin]

Check the sprag clutch on the alternator drive pully... if it isn't that it might be the A/C compressor bearing.