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Early Warning Signs of impending parts failures

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Author Post
Sat Jan 03 2015, 06:52pm
Joined: Dec 02 2013
Member No: #1508
Location: Wales
Having just experienced a failure of the alternator clutch, I realise that there have been warning signs for a couple of months which I didn’t recognise. I thought it might be useful to start a thread listing the less obvious symptoms associated with the “routine” faults on these cars.

In the case of the alternator clutch, it all makes sense with hindsight! The purpose of the clutch is to reduce noise and vibration. I have spent the last couple of months feeling that my car was not as refined as it used to be – not uncouth, but just a little bit harsh, particularly when accelerating or cruising on a motorway. I suspected wheel bearings, engine/gearbox mountings and even noise deadening panels but couldn’t find the cause. Over the last couple of days, there was a very uncouth shudder every time I turned the engine off which had me checking engine and gearbox mounts again. Then the alternator warning appeared, I read the forum postings and everything fell into place.

So, combining my experiences with some of those on the forum, we have:

1. Occasional sound of canaries or crickets

2. Increased engine noise/vibration

3. Red dust accumulation under the alternator and on the air con compressor

4. Shuddering on engine shutdown

5. No battery charge

Diagnosis = Alternator clutch failure

Recognising 1-4 above might just allow the time to accumulate the parts and tools without limping home with no lights and no heater, or worse still waiting for a tow truck.
3 User said Thank You to c6kev for this Post :
 Cisco (03 January 2015) , C6Dave (04 January 2015) , userpco (05 July 2015)
Sat Jan 03 2015, 06:58pm
Joined: Dec 02 2013
Member No: #1508
Location: Wales
A year ago I experienced the dreaded thermostat housing failure and realised that the warning signs had been there throughout the three weeks that I had owned the car.

When the housing starts to split, the two halves spring together so that water loss is minimal. It is only when revs exceed 2500 or 3000, that the increased water flow/pressure forces the joint apart and allows rapid coolant loss.

This allowed me to make my first journey in my “new” C6 from Norfolk to central Scotland to North Wales with no significant loss of coolant (driving for economy and comfort), the only fault being an intermittent “suspension faulty” warning.

On return to home, I found small droplets of coolant over the right hand suspension strut top just behind the header tank. After replacing the defective header tank cap, I expected the droplets to disappear, but was disappointed that they kept recurring (as did the ”suspension faulty” warning).

A couple of weeks later (New Year’s Day), I found myself descending a steep torturous hill in low gear using the engine for braking and running at about 3000 rpm. Suddenly the heater started to produce cold air.

Investigation revealed that I had lost 2 litres of coolant in a 20 mile journey. After topping up, and running gently at low revs, everything worked fine (but still with the suspension warning).

With head under the bonnet, engine cover removed and engine running, there was no sign of water loss. However, with the bonnet open and sitting in the driving seat, it was a different story as I squeezed the throttle. As the revs increased through 2500, a fountain erupted from the thermostat housing and completely subsided when I released the throttle.

After replacing the thermostat, all is well AND the “suspension faulty” warning has disappeared.

There are postings on the forum suggesting that the thermostat failure is sudden and catastrophic. This is because it is only really obvious at high revs which is usually when the engine is working hard and really needs to retain its coolant. However, there are warning signs which might allow the fault to be detected before it becomes catastrophic.

1. “Suspension faulty” warning, if associated with dampness around the right had front strut top.

2. Small water droplets on the exposed metalwork at the back right hand side of the engine bay

3. A jet of water in the engine bay above 3000 rpm – easily observed from the driving seat with the bonnet up.

Given the potential consequence of not seeing the warning signs, it is worth a quick look under the bonnet every week or so.
3 User said Thank You to c6kev for this Post :
 Cisco (03 January 2015) , drummond (05 January 2015) , userpco (05 July 2015)
Tue Jan 27 2015, 07:35pm
Joined: Feb 28 2014
Member No: #1605
Location: Staffordshire
I too suffered an alternator clutch failure with similair symptoms to the above although the noise was a distinct rattle which peaked with increasing revs. After researching several threads and contacting various members (thanks to you all) I ordered an alternator clutch from - Click Here - ,priced £62, a gamble yes, but a well informed one .

The main problem then was to convince a garage that the whole alternator did not need replacing! I suffered much sucking of teeth and quotes ranging from £500 to £1200. Eventually a Peugot/Citroen specialist said he'd fit the clutch but then gave up at the first attempt, ("it's a pig to get to" was the only excuse he could manage.)

In the end my local independent garage fitted it and threw in an MOT and an oil and filter change for £350- Bonus. He agreed it was an awkward job and stated most garages would not bother to try to get the part or the removal tool - far easier to just say its the alternator.

Common sense should dictate that most modern alternators should last for more than 80000 miles and even my limited mechanical knowledge combined with this site's invaluable help has proved the assumption correct. Saved some dosh too!

Thanks to all members who have helped in this and other threads.
2 User said Thank You to Junksleeper for this Post :
 cruiserphil (27 January 2015) , userpco (05 July 2015)
Fri Apr 24 2015, 11:42am
Joined: Sep 13 2012
Member No: #1021
Location: Coventry, Warwickshire
My local Garage replaced the clutch on my alternator and yes, its a pig to get at but the job is fairly easy to do.

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