JamesBB said:

Hi All

Last month I replaced my serpentine belt, the tensioner and water pump.
All is running ok, except I have a whining noise now, seems to be coming from around the tensioner area, but hard to tell. Sounds like it is too tight now. Before it was all quiet.

The parts I used were all better quality parts from Dayco, Airtex etc. No Britpart.
Alternator and AC compressor are ok I am sure. Tomorrow I will have another look and listen.

Anybody experienced this before on a GEMS engine? 4.6 no LPG.
Cheers

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martynv8 said:

I had the same when i put a new Dayco belt on. It ended up being the idler pulley but threw the sound around & first thought it was the Alternator. I went for the metal type as OEM are plastic & can disintegrate.

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JamesBB said:

That is my suspicion too. LH idler under the tensioner. At the moment I believe mine is plastic, so worth swapping for a metal one.

I think the alternator is ok as I completely removed it when I did the work (changed valley gasket too) and it spun without any alarming noises.
Same with the AC compressor (used 12v to engage the clutch while it was off), so I do not think it is that either. AC on or off makes no difference.

Will check more today.

Cheers

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JamesBB said:

This is the GEMS belt. The tensioner seems to be the only part ERR6439G, no separate idler on the LH. I have replaced that, so I am confused over the source of the noise.

Bosch/Thors seem to have the extra LH idler.

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wammers said:

The part you have ringed in red is the tensioner. The idler is the small one on the right hand side of the picture. Just to the right of and above the crank pulley. This one Roller Idler - Timing Belt - Genuine Land Rover at www.rimmerbros.co.uk or one of these Island 4x4 - Specialists in Land Rover and Range Rover Parts and accessories for all models. UK and worldwide mail order. take your pick

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JamesBB said:

Yes that is what I thought. Thanks.

I have actually narrowed the noise source down. I took an 18 inch long piece of timber and rested it on each component with a pulley to listen at the end. The only thing with an even similar whine is the AC compressor, but it makes no difference if the AC is on or off. However, that is probably because there is no gas in the system.

Some questions:
Am I correct in saying if there is no gas the clutch does not engage as the dual pressure switch stops it and this saves the bearings?
Would a re-gas fix it?
Or should i take it that the bearings are worn and I need to replace?

Maybe the new belt and tensioner has just shown up a fault that has been there for a long time.......

Cheers

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wammers said:

There is an idler bearing in the compressor clutch pulley that takes the rotation when the clutch is not engaged. When the clutch is engaged the bearings in the compressor take the rotation and the idler bearing in the pulley is still. So if you had a re gas and with the compressor engaged the noise goes away it's a safe bet it is the compressor pulley idler bearing that is your problem. If it is take it off pull the bearing read the numbers and get one from here. Simply Bearings Ltd ~ Oil Seals SKF FAG TIMKEN KOYO NTN NKE TRULOC Needle Rollers Taper Rollers Rod Ends Oil Filled Bushes Loose Balls O Rings Grease Plain Thrust

PS Or if you fancy find the feed wire to the magnetic clutch and feed 12 volts to it with the engine running see if the noise stops. Not for long though if there is no gas in. Moments only.

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JamesBB said:

Update.

Belt off and checked alignment, all seems fine.
Checked each pulley for noise and wobble. The idler under the steering pump sounds awful, spins freely, but a bit scratchy and rough.

With the engine running I engaged the AC clutch with 12v, and the noise does not change at all.

So it must be either the idler that is making all the noise, or the AC pump bearings are worn also. Could the noise of the idler travel through to the AC pump when listening via a length of wood? Cannot hear it on the PS pump, which is closer.

Cheers

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wammers said:

Will be the idler under the power steering pump as first suggested. They do go pretty often.

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martynv8 said:

I had the same when i put a new Dayco belt on. It ended up being the idler pulley but threw the sound around & first thought it was the Alternator. I went for the metal type as OEM are plastic & can disintegrate.

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JamesBB said:

Thanks, better get one then. I guess it is not a risk at the moment, just an annoyance.

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JamesBB said:

Just an update as I forgot to make one last month.
New idler fitted, bloody noise still there.

I am very sure it is coming from the AC compressor.

When I stripped it all down (to do more than the belt etc) I took the compressor completely off so I could access the rocker gaskets etc.
When I took it off it gave me the opportunity to change the O rings too, but as I turned it sideways some fluid leaked out of the holes, a very small amount - maybe 2 - 3 table spoons or so.

Could this be some compressor oil?
Checking Rave it uses 0.32 US pint of Sanden SP10.

I could "put" some back in via the holes it came from, but there also seems to be an oil plug.....

Could anybody advise on this please?

Found this for a Sanden compressor:
Compressor lubrication occurs as the oil which circulates with the refrigerant passes
through the compressor crankcase during operation. The Sanden SD series (not sure if LR uses this) compressor achieves optimal durability and cooling performance when oil circulates through the system at a ratio of 3.3% to 8% oil to refrigerant.

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