C5 2.2 Hdi noise from auxilliary belt area

[KevMayer]

Last week my C5 suddenly started to make noises from the aux belt end of the engine.

My first thought was crankshaft pulley breaking up, so, today I got a new pulley from GSF. It's solid without any rubber and so is a backward step in terms of soaking up aux belt sudden load pick up, but, it should work ok.

My first problem was to undo the pulley bolt. This had been off 40K miles ago when the cambelt was changed by my local dealer, but, the mechanic who replaced the bolt must have used the whole stock of western europes thread lock because it was an absolute pain to get out. It was extremely tight right up to nearly the last thread. So much so that I thought the bolt was going to snap.

Anyway, eventually the bolt was out and I wire brushed the thread lock off the threads and used a screwdriver to get it out of the threaded hole in the crank.

Too much thread lock is just not necessary.

With the new pulley on and everthing back together I still have a noise but its not as noisy as it was. A low level ticking has gone, so the crank pulley must have been failing for some time and I just didn't realise. I'm left with a high tone 'twanging' noise at low revs. This is the new noise I noticed last week. It looks like I need to replace the aux belt tensioner to cure this one, but, the tensioner is simple compared to the crank pulley.

[KevMayer]

I've replaced the aux belt tensioner but still have a noise.

I've googled around and it looks like I may have a faulty alternator pulley.

The alternator pulley has a ratchet type mechanism refered to as a clutch. It allows the alternator to freewheel on over run apparently. I'm not quite sure I fully understand it, but, it's designed to reduce the belt flapping and to reduce the duty on the tensioner.

You get a problem when the ratchet becomes faulty and locks up, so giving more flapping of the belt and more vibration of the tensioner at low speed/tickover.

This is exactly what I seem to have with lots of noise at tickover and low speed but it goes quiet as the revs increase.

I have two options. I either replace the pulley or replace the whole alternator. The pulley plus special tool will cost £42.50. A new alternator will cost about £150.

Any thoughts?

[daviemck2006]

I got an alternator for a 2.2 for 117+vat from alternatormart.com in january. ordered thursday, delivered tuesday, after payng extra for next day delivery. It did come with the pulley attached and was qyite simple to fit. Citroen stealer wanted 609+vat just for the part, he got sworn at!!!!!!!!!

[ataxidriver64]

Seems that you have bought the wrong pulley for your car, and no it wont work ok if yours had a spring loaded pulley on before.
Send the pulley back to GSF and get them to send the correct one.

[Johnno]

I've a very similar sounding problem. After changing the (very) worn cranksahft pulley, I've now noticed that the belt is flapping at low revs/idle on the tight-side of the pulley, between the pulley and the aircon. I suspect that the problem was masked by the noise from the pulley.

I was beginning to suspect that the replacement pulley was a dud - but given that there is definitely a ticking noise (which sounds a bit like a relay) from near the alternator and given Kev's post, perhaps not.

A replacement clutch pulley is around £26 and the tool is some £14; is there a particular part number for the removal tool? And can the pulley be checked manually whilst still on the car?

As the cambelt change is to be done soon (thanks for the info Kev - I managed to get into my old email account), I want to do everything at once.

Cheers all.

[KevMayer]

You can test the alternator clutch pulley using a thin screwdriver.

You need to insert the screwdriver blade through the vent holes at the back of the alternator (non pulley end) and try to make the fan rotate.

If the clutch pulley is working the fan will be stiff in one direction but should rotate in the other.

I'd disconnect the battery before doing this because it's connected directly to the alternator without a fuse.

The tool to change the pulley is either Torx T50 or a 10mm spline.

I used a torch and mirror to check my pulley. There's an end cap on the pulley so I took that off, had a look and it was T50, so, I tried a T50 socket in it. It fitted ok. I put the end cap back on and, when I tried the engine, and since then, my noise has gone away. I don't know what I've changed but it seems alright now. This suggests to me that there may have been some dust or mud in the pulley clutch. I was planning to get the right tool and take my pulley off to give it a flush with petrol and re grease.


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