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The Hulk



Member Since: 13 Apr 2016
Location: Aberdeenshire
Posts: 81
Scotland 1997 Defender 110 300 Tdi HT Aintree Green
Supercharger whine? Nope it's the alternator
On a defender? Nope, it must be something else.

I'm hearing what can only be described as a mechanical whine, not unlike a supercharger, which changes note with engine revs. It doesn't sound bad, it's just there. I first thought it was gearbox related but it's there when stationary in neutral. It sounds like it's coming from the rear of the engine but it's nothing like a clutch release bearing, which was my second thought.

In the short time I've had this Defender, I've discovered what a PTO is - every day is a school day - and as this motor has a hydraulic pump for a winch I'm wondering if that could be causing the whine?

Any suggestions on how to cure it, if indeed it needs to be cured. Is it just a side-effect of the PTO being employed?

Last edited by The Hulk on 31st May 2016 7:50pm. Edited 1 time in total
Post #523931 14th Apr 2016 3:59pm
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shaggydog



Member Since: 12 Aug 2012
Location: Kent
Posts: 3347
United Kingdom 1991 Defender 110 200 Tdi USW Arles Blue
The PTO runs off the back of the transfer gearbox so if it is still whining with the clutch disengaged (no drive) then it wont be the PTO pump as it should not be moving.

The PTO should have a engage/disengage lever in the foot well somewhere, make sure it is disengaged and then see if it does it again.

Otherwise could be signs of a worn turbo, though that is more of a whistle then a whine. Running Restoration Thread http://www.defender2.net/forum/post323197.html#323197

Self confessed mileage hunter Very Happy
Post #523934 14th Apr 2016 4:14pm
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The Hulk



Member Since: 13 Apr 2016
Location: Aberdeenshire
Posts: 81
Scotland 1997 Defender 110 300 Tdi HT Aintree Green
Ah, I didn't try it with the clutch depressed. Another job for this evening...

I found and activated the PTO lever the other day. The warning buzzer on the relay is loud enough to drown out everything else!
Post #523937 14th Apr 2016 4:24pm
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I Like Old Skool



Member Since: 23 Feb 2015
Location: Manchester
Posts: 814
United Kingdom 1994 Defender 110 300 Tdi ST Coniston Green
Could be water pump or powersteering pump on way out. These can get a bit noisy towards the end if the bearings are going bad. Sometimes get driven past by old cars or vans where the noise is so bad/obvious that I wonder how they are still running. It might be worth whipping off the ancillary belt and running the engine without it to see if the noise has gone.
Post #523946 14th Apr 2016 4:47pm
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Al_The_Pal



Member Since: 09 Feb 2015
Location: Near the bottom on the right
Posts: 146
2015 Defender 110 Puma 2.2 XS CSW Corris Grey
What age car? Our 15MY has a "straight cut gear" noise from the back of the engine that I'm quite liking at the moment, no such sound from our 300Tdi Smile

I'd assumed that this Supercharger/Straight cut noise was normal for a Puma?
Post #523972 14th Apr 2016 6:04pm
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The Hulk



Member Since: 13 Apr 2016
Location: Aberdeenshire
Posts: 81
Scotland 1997 Defender 110 300 Tdi HT Aintree Green
It's a 97 300Tdi
Post #523986 14th Apr 2016 7:13pm
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The Hulk



Member Since: 13 Apr 2016
Location: Aberdeenshire
Posts: 81
Scotland 1997 Defender 110 300 Tdi HT Aintree Green
I Like Old Skool wrote:
Could be water pump or powersteering pump on way out. These can get a bit noisy towards the end if the bearings are going bad. Sometimes get driven past by old cars or vans where the noise is so bad/obvious that I wonder how they are still running. It might be worth whipping off the ancillary belt and running the engine without it to see if the noise has gone.

Surprise surprise! It's nothing to do with the PTO as it disappears when the belt is off. The water pump looks like it's brand new and I recall the PO saying it had been replaced. So does this mean it's the power steering pump? Or could it be the alternator? The noise appears to be in the area around the turbo (which it obviously isn't). What about the tensioner itself? Mid Life; Live It!

Ongoing thread: http://www.defender2.net/forum/topic45697.html
110 300Tdi Utility (Hulk)
90 300Tdi SW (GF's Tank)
Post #536062 31st May 2016 10:26am
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The Hulk



Member Since: 13 Apr 2016
Location: Aberdeenshire
Posts: 81
Scotland 1997 Defender 110 300 Tdi HT Aintree Green
Ok it's clearly not the power steering pump because that isn't attached to the auxiliary belt. Still learning about this motor Laughing [How is the steering pump powered on a TDi?]

I've spun the various pulleys and concluded it's the alternator that's making the noise. It's charging fine but the bearings are clearly on the way out. The thing has been duly removed and I'm now wondering if it's serviceable? I know the brushes can be replaced but what about the bearings? I've also noticed a couple of cracks in the housing. Should I just replace it or continue to take it apart..?


Click image to enlarge Mid Life; Live It!

Ongoing thread: http://www.defender2.net/forum/topic45697.html
110 300Tdi Utility (Hulk)
90 300Tdi SW (GF's Tank)
Post #536278 31st May 2016 7:50pm
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I Like Old Skool



Member Since: 23 Feb 2015
Location: Manchester
Posts: 814
United Kingdom 1994 Defender 110 300 Tdi ST Coniston Green
I rebuilt my alternator last year but it was a pig of a job for an amateur bodger like me and I very nearly couldn't get the front bearing out. If your alternator casing is already cracked then it has to be replacement time.

I Like Old Skool wrote:
Finished night shifts this morning and decided to stay up and rebuild the alternator on my 300 tdi. Bought the bearings and a new regulator/brush pack from JCR supplies - http://www.jcrsupplies.co.uk/products/ALTE...ATORS.html

They were cheap as chips but still supplied top quality FAG bearing for the main one and their own bagged item for the closed cup bearing. All together now, lovely and quiet. Was getting quite rumbly before so this is one less thing to worry about. Kicking out 14.3 volts straight away just at idle. It was good to see the battery light go straight out after I fitted the rebuilt unit.

Found a build sticker on the alternator that shows it is the original one made in 1994. Not bad for 21 years and just short of 140k miles. Was still working reliably so might have lasted a lot longer, it definitely will now Thumbs Up
Post #537361 3rd Jun 2016 11:16pm
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shaggydog



Member Since: 12 Aug 2012
Location: Kent
Posts: 3347
United Kingdom 1991 Defender 110 200 Tdi USW Arles Blue
For what its worth and what a new one costs I would just put a new one on and ditch the old one. Running Restoration Thread http://www.defender2.net/forum/post323197.html#323197

Self confessed mileage hunter Very Happy
Post #537491 4th Jun 2016 3:47pm
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The Hulk



Member Since: 13 Apr 2016
Location: Aberdeenshire
Posts: 81
Scotland 1997 Defender 110 300 Tdi HT Aintree Green
I've bitten the bullet and acquired a new 100A alternator. It's the same manufacturer as the old one (Denso?) and it was three times the price of some of the units than can be bought on line but I gather they only last for three months. This should be good for many years.

One fly in the ointment was once I got everything back in place and connected up the wires, I couldn't get the belt on. Silly me assumed that the new alternator pulley was the same as the old one. I removed the unit again (a half hour job which now takes 5 minutes) and discovered the pulley was larger diameter than the original. It also had five ridges to the originals six. And could I remove it? No matter how hard I tried the 24mm nuts on both alternators were impossible to shift. Thankfully there's a mechanic along the road and he was due me a favour. A few seconds with his impact gun and they were swapped over. I don't know how those guns work but I definitely need one in my life Bow down

So now it's all sorted and running beautifully. I can now hear the myriad of other things that are going to go wrong which were previously drowned out by the alternator bearing whine Rolling with laughter Time for a glass of wine! Mid Life; Live It!

Ongoing thread: http://www.defender2.net/forum/topic45697.html
110 300Tdi Utility (Hulk)
90 300Tdi SW (GF's Tank)
Post #539892 13th Jun 2016 5:34pm
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