HDI ticking noise at 1200 - 2000 rpm any ideas

[selectcase]

HI

first things first merry Christmas I hope its been good for everyone

just before Christmas on the way home my 406 110hdi estate started making a really loud ticking nose at all rpm's - I really thought it was the big ends or something on the way out

after taking off the aux belt the noise went and after reading some posts on this forum I found the alternator clutch was seized. I had already replaced the tensioner, belt and idler pulley in the past year along with the crank pulley as part of a big service I gave it in the spring.

so as I intend to keep the car I bought a quality replacement alternator at a cost of £150. This has stopped the noise at tick over but it its still there between 1200 and 2000 rpm - it sounds a bit like a work crank pulley.

so today I changed over the auxiliary belt - no difference
changed the fixed idler, cam adjuster pulley - no difference
I double checked the adjustment/tension of the belt - no difference

I am running out of ideas really - my stethoscope cannot pinpoint the problem but it disappears if I take of the belt and the tensioner is not jumping around any more.


could it be the aircon compressor?? and if so is there any way of checking it or can I get a belt to bypass it?

any ideas welcome bearing in mind I have eliminated the belt, non sprung tensioner, alternator and crank pulley?

[rwb]

The favourite for a ticking noise is the bottom pulley. When it starts to disintegrate strips of metal ribbon work their way out of it and catch, causing the ticking. Hopefully (?!) you can see or feel these?

[selectcase]

Yes I had replaced that in the summer but thanks for the idea

[Bailes1992]

Could have failed again?
Cheap aftermarket items are lucky to last 6 months!
Replace it with a good quality OEM quality part.
If it's still ticking then you have worn injectors.

[lozz]

It couid be the clutched/pulley on air/con.

give it a spray with Wd40, thus avoiding contact with the Auxbelt,
and see if noise Quietens,

[selectcase]

It couid be the clutched/pulley on air/con.

give it a spray with Wd40, thus avoiding contact with the Auxbelt,
and see if noise Quietens,

Thanks for the advice - I will give it a go - I notice the clutch does not engage because it needs regassing so I might well be this