Moaning/Groaning Discovery 2

[davros]

Hi All,
Just wondering if anyone can offer advice here...
Mysterious moaning noise has developed, and it's not the fun sort, coming from my 2000 D2 TD5, 250,000km. It is a quite similar sound to a hot auto trans at the top of a long hill. I have had a new transmission fitted but not sure it's that - certainly it didn't do it when I picked up the vehicle a few months back.
It changes with revs not speed, and is present in low and high range.
I have a steering box on the way out, 'damp-almost-dripping' drop arm with some movement. Underside of PS pump was damp but I suspect the flange was loose; once tightened it has not got worse.
I have an unidentified dry sounding bearing in the front (fan, fan hub bearing, idler and AC bearing replaced, leaves PS pump, alternator and ACE. Used stethoscope but hard to tell as whole lot is noisy!)
I suspect the power steering or ACE but don't want to replace parts unnecessarily. There is some endplay in the ACE pulley but no leak.
The noise 'disappears' and 'reappears'. It tends to 'activate' after a turn or hard acceleration, and often vanishes on a slight uphill slope. It doesn't do it at idle or when revved in P. CORRECTION IT DOES MAKE THE NOISE WHEN REVVED IN P OR N!
When it goes, it 'fades out' rapidly and stays gone for a while.
The noise is usually present at start up.
The noise is not loud and tends not to be noticed by non-disco people (sell it now??!!)
Fluid is due for replacing but I don't want to do so until I identify noise.
Can air be drawn into the PS system through the PS box leaking seal? Or would internal pressure prohibit this?:confused:

Cheers,

Dave

[davros]

BUMP!
Someone? I do have some further info - I thought an incline made the difference, but it seems to be the small roundabout I go through before the hill that clears the noise.
ATF fluid level is ok.
Another similar set of curves also 'fixed' the noise, but on a long straight run it slowly returns. Is it the left/right turn that bleeds the steering/ Or would it be the ACE swaying through the corners??
It is by no means a harsh 'about to explode' sound. Just this faint droning noise!
Frustrated!
Dave :)

[Ean Austral]

Harmonic Balancer?

[DEFENDERZOOK]

is your power steering fluid aerated when its making the noise......?


on my fender.....the power steering pump front bearing collapsed......and it was sucking in air and aerating the fluid till it was spurting out the reservoir cap......
youd think it would leak oil out through the seal instead of sucking in air......

[davros]

Dont think it's the balancer or it would be more constant Ean? Defenderzook, I wouldn't say it's aerated, just sloshing about as usual. Unless it IS my new transmission making the noise... Might be one of those wait-till-it-gets-worse scenarious, however, I want to ping any transmision probse before the warranty wears off!
So it seem a quick left right turn, like a small roundabout or series of turns, and after about another 20-30meters, the sound vanishes. It seems to be on right hand side front, and is audidly over the usual 250,000 km+ TD5 clatter! But it wouldn't be noticed unless pointed out.
So, P steering? ACE rams rocking back and forth? or trans fluid sloshing about? something like air in the TC or a pump issue?
I think a failed bearing like front Trans Case output or similar would just whine constantly? I will check T case fluid level though.
Will old fluid in the PS and ACE cause issues of noise? new penrite PS fluid for ACE systems ready to go in but don't want to waste it!

Thanks guys,

Dave

PS possibly similar issues elsewhere?

Moaning noise only with right turn - Land Rover Forums : Land Rover and Range Rover Forum (http://www.landroversonly.com/forums/f40/moaning-noise-only-right-turn-22909/)

Steering "groan" and leak - Land Rover Forums : Land Rover and Range Rover Forum (http://www.landroversonly.com/forums/f40/steering-groan-leak-45590/)

And what's this?

Front Frame Spacer Noise - Land Rover Forums - Land Rover Enthusiast Forum (http://www.landroverforums.com/forum/showthread.php't=25810)

[davros]

opps posted twice ... deleted repeat through edit but dunno how to delete post!

[INDIE2002UK]

Has the filter in the valve block for the ace system been replaced at all? The ace system on these car do get harsher with time

[bellmore]

And what's this?

Front Frame Spacer Noise - Land Rover Forums - Land Rover Enthusiast Forum (http://www.landroverforums.com/forum/showthread.php't=25810)
I think it refers to the attached

[davros]

Thanks people!
Will look at the possibilities!
If nothing found... wait till it gets worse!

[davros]

Ok. Still no sign of the cause, but a bit more narrowed down to when it happens.
Always has an engine speed moan when starting after a long rest. Usually fades out after a few up/downhill runs (less than 5 mins). Does not get louder under load.

Noise returns during long runs on straights. It "fades out" after an uphill run (then stays gone for a while no matter what load/revs/speed etc). I was mistaken about the steering affecting things; its a steeper hill that helps; even a small one.

The only v minor fluid leak that occurs is a damp drop-arm.

It could be from the ACE block or my newly recon transmission?

Either way, any suggestions?

It almost sounds like air in a system getting bled out when car is on an uphill angle.

Could it be far worse like an improperly rebuilt trans and something moves rearwards when going uphill, then slowly moves fwds when on the level?

You may have read - I have replaced the Harmonic balancer. What a diff it made to the TD5 '2250rpm vibes'. I reckon a lot of harmonic balancers may look fine rubber-wise but the center bearing is stuffed like mine was!

Made no diff to 'the moan' though! Seems to be on the right of the motor...

I did the ACE filter 50,000 ago; needs doing but why would it be affected by hills? And why does it slowly return on the straight??

Downhill does not make it worse but it will not fade out on a downhill run.

Dave

[GAServices]

Dave,

This thread started a year ago, so not sure whether you still have the truck or the problem.

We had one that developed the moaning / groaning: it's caused by the ACE system and there has been a TSB from land rover about it.

The long and the short is that it is an acoustic vibration. The whole ACE system, from pipes at the pump to the control block bolted to the chassis under the driver seat out to the actuators on the sway bar is isolated from the chassis on rubber mounts. If a pipe or the valve block touches the chassis or body the acoustic vibration sets in.

The stats for the ACE pressures and flow through volumes are mind boggling high as it is sitting waiting for you to trigger a g force sensor and require fluid in an instant. When you drive straight it just bypasses.

There are 4 rubber grommets surrounding the valve block mounting bolts. If they collapse or a stone or mud gets in behind the block the valve bypassing sound will transfer. Likewise if a pipe moves into contact with the chassis.

Good Luck finding where it has grounded!

Steven

[rover-56]

Check for a stone between the ACE valve block and the chassis.
Might be lucky. I fixed that noise once on mine that way. Otherwise ACE piping touching somewhere it shouldn't.

Cheers,
Terry
2000 D2 TD5 with ACE