Sneaky pulley noise..grrrr!

[PeterH]

Last week I started to notice a slight tapping/squeal noise, which definately sounds pulley related.
It happens under load and comes and goes a bit.
I had never changed my serpentine belt, so for good measure I put a new one on today.
As soon as I drove off the noise is still there.
While the belt was off, I checked all the pulleys for any rough rotation, they all felt perfect.
This is a bit of a hard one to diagnose, as it will not make the noise while idling, only while the car is actually in motion and under load.
Now like most of you, I like to keep my P38 in good order, and noises of any type need to be investigated, to avoid something chucking a wobbly while driving.
I'm not getting any warning lights on the dash, the car is driving perfectly otherwise.
I'm thinking belt tensioner or pulley maybe?
I'm hoping it's not a bearing giving way somewhere...
Has anyone else had this happen?
What would be the most likely culprit?
2001 4.6 Thor HSE
Cheers, Pete.

[wayneg]

I had a pulley / belt noise most noticeable on tickover. It drove me crazy trying to sort it. I was convinced it was the air con compressor clutch bearing as I could stop and start the noise with the aircon kicking in. I changed the clutch bearing and still had the noise. The alternator is not very old so discounted that. I then changed the pulley under the power steering, still there. Then the tensioner Pulley, still there, Finally I got to the Idler pulley directly below the alternator, Result noise gone.
The pulley in question is Plastic. The surface had worn down until only a very thin layer was left, I think I put a post up at the time with a warning.
The new pulley is a nice chunk of steel.

https://www.aulro.com/afvb/images/imported/2013/09/874.jpg

I just found this Picture of a failed pulley, mine was still intact but as you can see the surface wears away and its not clear until BANG. Maybe not your issue but I would look there anyway.
https://www.aulro.com/afvb/images/imported/2013/09/875.jpg

Have a read, if yours proves the same maybe post again with a general warning........
http://www.aulro.com/afvb/p38a-range-rover/172455-thor-engine-idler-pulley-under-alternator.html

[mtb_gary]

I like the look of the bogan battery cover :D

Gary

[wayneg]

I like the look of the bogan battery cover :D

Gary

Can I please clear this up before it gets out of hand and rumers start to spread, Thats not my car, Not my battery cover, I have never owned a Lumberjack shirt and never will.
( No offence to lumberjack shirt fans)

https://www.aulro.com/afvb/images/imported/2013/09/869.jpg

[PeterH]

Thanks for sharing that Wayneg, great photo too!
I might get under there again tomorrow, pull the belt back off and check that pulley.
I know sometimes these things become a process of elimination, but that is a good start.
Will let you know how I go.

[wayneg]

Thanks for sharing that Wayneg, great photo too!
I might get under there again tomorrow, pull the belt back off and check that pulley.
I know sometimes these things become a process of elimination, but that is a good start.
Will let you know how I go.

Just an add, I looked at the pulley at the start and it seemed fine, at least the bearing was not noisy. Now I know the surface should be flat right across the belt contact surface. If you have ridges at the edges thats the sign of wear, I presume the plastic becomes so thin it starts to flex

[PeterH]

OK, the noise is getting a bit worse today, and still only does it during driving.
When at idle there is no unusual sound at all, which is a bit frustrating to say the least!
I let the tension off the belt, checked all the pulleys and every one turned freely without any noise.
The idler pulleys are both metal ones and I could not detect any problems with those.
I did notice a 1mm movement when I pulled on the steering pump pulley, and in and out movement rather than a side to side movement. The pulley spins freely though, with no noise nor roughness at all.
There was also a very slight movement of the fan via the viscous coupling, but it seems to be working fine.
The sound has develpoed into what sounds like a chirping belt, sometimes catching, like a metallic clunk.
I'm wondering if I'm on the right track, maybe it's something else, but so hard to tell as it only happens while driving.
Anything I'm missing here?
Thanks, Pete.

[Hoges]

PM sent

[wayneg]

If you turn the aircon on, when the compressor is running you will put additional load on the belt, does that force the noise to start? Also recall someone had the power steering pump pulley work loose
http://www.aulro.com/afvb/p38a-range-rover/161911-power-steering-pump-pulley-bolt-thor.html

[PeterH]

I just got my lovely lady to drive the Rangie for me, while I listened from outside, and could hear the clunks quite loudly...I'm thinking it may be a broken axle!
I had not heard it from outside the vehicle before, but had noticed a new clunk when taking off in forward or reverse.
I'll jack the front up tomorrow and see if I can spin the wheels by hand...that would explain why all the pulleys seem fine!

[PeterH]

Thanks wayneg, I did try the aircon, but that made no difference...see my other post for new findings!

[wayneg]

Does not sound to good, Front or back? If front make sure the viscous coupling has not seized, my experience of this caused the CVjoint to give up ( on a Classic)

[PeterH]

Thanks again wayneg, it is in the front, yes, a CV joint would make sense too with the clunking...what is the best way to check the viscous coupling on a P38?
Cheers, Pete.

[wayneg]

If its OK check the cv boots to see if one has failed, will cause premature wear


Range Rover P38 (P38a) Viscous Coupling (VCU) Test - YouTube

[Hoges]

Thanks again wayneg, it is in the front, yes, a CV joint would make sense too with the clunking...what is the best way to check the viscous coupling on a P38?
Cheers, Pete.

Another way is to slowly drive in a circle on a fairly tight lock ...as per a U turn for example, with driver's window down and listen /feel for symptoms of skidding/skipping in the steering. If symptoms are there, VC is either seized or close to it....


EDIT: Have you checked for sloppiness in the front U-joints?

[PeterH]

Will be doing that tomorrow, thanks wayneg!
It all makes sense now, the clunking is much worse while turning, the noise only occured while in motion, was not thinking it being a cv joint...was very hard to tell from the drivers seat.

[PeterH]

Yes I only greased the diveline a couple of weeks ago and all the uni joints seemed solid.
One thing occured to me...a couple of months ago I put new tyres on the front.
I couldn't afford to shell out for all 4 on one go, although the rears are almost due for change too.
There is probably a 12mm + difference in the tread depth from the newwies on the front and the oldies on the rear.
I have noticed some vibration since the new tyres have been on, I was suspecting the new tyres were not balanced correctly, but maybe the difference in tread depth was causing the vc to work harder?
Anyway, I'll check the vc tomorrow...will let you know.
Thanks for all the help!

[PeterH]

I did the viscous coupling check as in the video, fortunately that seems fine.
I'm suspecting the drivers side cv joint to be the culprit.
Now what is the best way to determine it is indeed the cv joint?
Sorry for all the questions, never tackled this job before.
Is there anything else I should be doing while I'm replacing the cv joint?
Should I be doing both sides or is it ok to just do the faulty side?
Thanks for all your help everyone.

[wayneg]

As Hoges viscous technique, Drive the car in a tight circle windows open and listen for clicking from the wheel. Did you look for a split boot?
You can do one side only with no problems, there is an axle seal that should be changed as well.
I did a write up on changing the CV. I got mine from the UK as massively cheaper
http://www.aulro.com/afvb/p38a-range-rover/122386-renew-cv-joint.html

This video might give you an idea however the CV on that car is truly long gone, The 1st signs arnt as bad and initially you cant always replicate the noise at will. When my one started I was not even aware of a problem until someone outside the car picked it up.

http://www.youtube.com/watch?v=j0pEp3yVS4o

Heres one from the USA....http://www.ebay.com.au/itm/WD-Express-422-29007-613-CV-Joint-/321040247322?pt=Motors_Car_Truck_Parts_Accessories&fits=Model%3ARange+Rover&hash=item4abf7d6a1a


If the CV is the issue it not going to break the bank and it quite easy if you follow my tips re the big nut. This lot ship to Aus, you will need the boot and seal too.......http://www.lrseries.com/shop/product/listing/12073/STC3204-CV-JOINT.html'search=stc3204&page=1

[PeterH]

Thanks wayneg, the noise I have is nothing like that one in the video, it is more of a metallic clunk, sometimes with a vibration, which comes and goes.
It does change with speed, seems to happen more at lower speeds.
I checked the boots which are intact and look fine.

I rang my trusted parts supplier today and had a chat about this, he has worked with P38's for years and said they very rarely had to replace cv joints in the many P38's they worked on and they had 3 or 4 in the shop on any given day.
He said if the viscous coupling tested ok, it is more likely to be a uni joint giving out.
It's so hard to tell from inside the vehicle in motion exactly where the noise is coming from.
He suggested replacing the two front uni joints and see if that fixes it.
He may be on the money there...at least I hope he is, uni joints are much cheaper than cv joints!
I did check for slop in the uni joints and they all felt solid, but there could be a needle bearing mashed causing the noise.
I did grease the driveline a couple of weeks ago, I wonder if I upset something by doing that.
So I'll try that first, will pick up some uni's tomorrow and fit them over the weekend..fingers crossed it does the trick.

[RR P38]

Earlier posts you were thinking it was coming from the engine?
A chirp I think you said, that sounds like the water pump bearing.

[PeterH]

Yes RR P38, from inside the cabin it really did sound like a belt squeal , but it seems to have progressed a bit to metallic clunks, it was not until I heard the noise from outside the vehicle yesterday, that caused me to rethink my first suspicions.
I did check every pulley including the water pump, but everything there seems to be ok.
When I heard it last night from outside, it had an axle clunking sound to it.
It is not there all the time which does make it hard to pinpoint.
I'd really like to get this one fixed as there is nothing worse than something breaking on the road.
I'll get under tomorrow and have a good look at all the uni joints for a start.
Cheers, Pete.

[PeterH]

SOLVED! I replaced the noisy cv joint, went for a drive and no more turning noises! Hooray!
Very happy about that, but still a vibration going on, so back under there and found a bit of slop in the very front uni joint.
Changed that uni with a new one and most of the vibration is now gone.
Thanks very much to wayneg and Hoges for your most helpful advice, you guys rock!
No wonder it was hard to diagnose, had a double banger with the cv joint and the uni joint.
It's driving vastly better now, but being the fussy P38 owner I am, I still have a very slight vibration at around 60km/h, I'm wondering if it is a wheel balance issue or the drive shaft is out of balance.
Anyway, I'm glad those jobs are out of the way, bit greasy under there!