Noise at front of engine

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Drive35
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#1 Noise at front of engine

Post by Drive35 » Mon Sep 21, 2020 9:57 am

Hi.
My 4.2 engine has developed an intermittant dinging noise at the front - seems to be from around the water pump/ lower timing chain area. Appreciate if someone can confirm my suspicions! :scratchheadyellow:
Thanks, Geoff
Geoff
1970 S2 2+2

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1954Etype
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#2 Re: Noise at front of engine

Post by 1954Etype » Mon Sep 21, 2020 10:13 am

Take the fan belts off and run the engine (very briefly). If the noise disappears then it is in the water pump, alternator or tensioner.

ANgus
Angus 67 FHC 1E33656
61 OTS 875047

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christopher storey
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#3 Re: Noise at front of engine

Post by christopher storey » Mon Sep 21, 2020 11:36 am

I must respectfully ( and only partly, in relation to his second sentence ) disagree with Angus !

I think this is a non-metallic noise, and my primary suspicion would be ( because I had this happen to me ) that it is a belt defect . I would take the belts off and inspect them very carefully for anything which has become impaled on them, and then check them for splits etc by bending them towards their outer surfaces throughout their whole lengths

Then, whilst they are off spin by hand those bits such as water pump and alternator( and air conditioning compressor) which are loose, and also check them for any obvious bearing play, as well as inspecting the driving inner surfaces of the pulleys

Is there an electromagnetic clutch on the AC compressor ? If so , check that it is not the noise of that trying but failing to engage

There is just one other faint possibility - could there be an intermittently defective HT lead , because the sound vaguely resembles that which you get when a spark from a healthy ignition system goes to earth

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chrisfell
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#4 Re: Noise at front of engine

Post by chrisfell » Mon Sep 21, 2020 11:47 am

I too had a similar belt issue. It had started to fray and the ticking noise was a single strand of wire gradually coming loose from the belt. It will be obvious it this is the cause as there will be a piece of wire sticking out of the belt.
Chris '67 S1 2+2

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#5 Re: Noise at front of engine

Post by 1954Etype » Mon Sep 21, 2020 12:40 pm

Christopher, no problem (in fact, I didn't listen to the video as I have no sound at work so you are probably correct!).

Removing the belt is always my favoured option as it very quickly identifies where the issue could be.


Angus
Angus 67 FHC 1E33656
61 OTS 875047

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Drive35
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#6 Re: Noise at front of engine

Post by Drive35 » Mon Sep 21, 2020 9:18 pm

Thanks for your help guys.
I only had time today to take the alternator belt off, but it stopped making the noise then. The belt looked OK, although worn and the alternator brushes made some noise, but after putting it back together, the noise has not come back, so I am assuming it was from the belt, or maybe something on the pulleys that has now shifted.

I initially thought it was in the timing chain, so very relieved it's not that :smile:
Geoff
1970 S2 2+2

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