Xantia II alternator belt auto-adjuster spring

[John Plum]

An interesting observation:

I had a squeal from the alternator belt drive area which died away whhen raising revs above tickover. The bottom of the belt jumped up and down, as if too loose.
Last night I cleaned the belt and wheels thoroughly, replaced and re-tightened. The spring moved under tension when turning the auto-adjustment plate with a 3/8 square drive with some strength. I tightened the belt with the manual eccentric tension wheel so as to free the rod, with aligned holes. The belt had been loose. Examination had told me that the idler bearing was a bit rough, though not terrible, and noted it for replacement.
The belt ran quiet yesterday evening, but returned today at the MOT, and worse at idle. I was told that the symptom of the belt jumping up and down was still there, indicating loose belt, after having mentioned the idler bearing. The mechanic asked me had I tightened the manual adjuster (answer yes). Then he told me he had done several of these auto tensioners, and assured me it was the spring not giving tension, and that was the reason for the jumping bottom stretch of the belt. By the way, he admired the car - the model, the recent work I've done, and said I have a good one. Encouraging words to hear, and he was a good chap. The car passed.

What are your thoughts about this
The tensioner moves OK, I thought. I see nothing odd, Should I test it in another way?

The eccentric tensioner wheel is about halfway to full tension, so I am going to tighten that more, as an experiment to see if the squeal dies.

In any case, I have heard this job to replace the spring and wheel complete is frightening people. I haven't found a post detailing the procedure, although I've heard mention of it. What does it entail, and how should I prepare myself?

[Stempy]

It's funny you should mention that as I have a squeal on my V6, but only when cold. As the belt warms up it's fine. I replaced the belt and the tensioner and cleaned all the pulleys, but it still squeals when cold, especially at start up. The only thing I haven't changed is the spring so I guess that is my next avenue of delight.

The V6 is fully automatic with no manual adjustment at all, so the tension is all down to the spring itself. Not a cheap item either

[HDI]

When the belt is jumping have a look at the spring belt tensioner , if thats jumping around it's mucked !! Replace it. When installing the new one check for correct tension by the arrows cast into the moving and fixed parts.
Persistently squealing belts can be caused by a pulley somewhere running out of line with the rest. I had this problem with my Xantia and it was due to an incorrectly installed hydraulic pump. It was mounted too far inboard by about 2 or 3 mm and the belt was rubbing on the side flange of the pulley.

[MikeT]

Has anyone experience of a product known as "belt dressing" I've read about on US forums? It's designed to aid friction of such belts apparently. I haven't seen it in the shops though I haven't been looking in earnest.

[CitroJim]

I have a squeal on my V6, but only when cold. As the belt warms up it's fine.

Stempy, do check your crank pulley. Paint a line across it and see if it moves, signifying the rubber bonding between the two halves of the pulley is starting to give up.

[Stempy]

Yoiks...better get on to that then.

With regard to belt dressing, I did try some platen clean which is used for restoring grip to printer platens

[HDI]

Multi rib serpentine belts should not need anything to increase grip , they were designed to eliminate the slipping problem that sometimes afflicted v belts.

[CitroJim]

John,

Most likely it'll be the spring tensioner duff. Follow this topic here to replace it. Not as hard as it looks.

I've had good results with Platen Clean in the past Stempy but not on auxillary belts. 'Tis sure good stuff even if it smells horrible...

[lexi]

My Crank pulley has harline cracks in the rubber bonding. Anyone got a guide to cost of new item and is it dealer only?. I am on similar journey to OP and my belt is running one rib over the edge of pulleys. Still gathering stuff to fix it all up.

I don`t think you have a proper sorted old Xantia until all these items are renewed. You can then happily do another 100k. That aux belt is deadly.

[John Plum]

don`t think you have a proper sorted old Xantia until all these items are renewed. You can then happily do another 100k. That aux belt is deadly.

I agree, The BX also had to be properly set on order to get the right sound - Quiet.
The guide to Replacement is great, most encouraging and useful. I like the 1/4 " drive tool idea, after struggling with length.

Meanwhile I have adjusted the eccentric belt tensioner again in two stage lengths s and test driven/observed, in particular the belt lower run for jumping, and the movement of the tensioner spring, as pointed out by HDI:

• 2/3 to full tension: the spring only vibrated up and down a little, on a few of the lower spring coils only. The squeal disappeared to a a mere wish at idle, a slapping with engine bay reverb remained. The lower run of the belt slapped less, only occasionally per X no. of revs - about every four seconds or so. ON revving above 1000 rpm approx, sound symptoms disappeared.
  
  full tension: the spring continues to vibrate in the same way. The lower run of the belt seems not to slap at all. The car is so QUIET..it's lovely, even at idle.

I am aware there are two belt versions , depending on AC compressor model. I suspect I have the correct one - the shorter one: the belt was not so easy to just 'slip on', and my problem is slackness.
I'm not yet 99% sure the spring is duff. I can't see why it should go, apart from weaken, but it seemed very strong to me, and doesn't appear to jump. I expect it should vibrate a little. I'm not expert with my eye in this, and the advice I got from the mechanic I mentioned may good, but not perfect in this instance: I know the tensioner bearing is a beginning to get rough though, and must be replaced anyway. A rough bearing might be causing some slap too, I think. But I could be wrong about the spring - it may be duff.
I'm thinking I'll try the set up next with a new belt, then decide what to do; bearing or bearing plus spring.

[John Plum]

I assume the tensioner wheel with bearing and sleeve can be replaced separately from the body and spring - if what I've learnt from reading is not wrong.

[HDI]

Nope , frayed knot !! The tensioner is only available as a complete unit.
The spring can fatigue or break and either will cause low tension and fluttering. Some movement is normal due to varying loads on the alternator , hydraulic pump etc , but we are only talking maybe 5 to 8 mm max.

[John Plum]

In that case, I've marked it up for replacement. Cheers HDI.

[John Plum]

I've checked the compressor (COMPRESSOR DELPHI FRANCE - 1135290) and belt sizes. My belt is stamped 1725 and the required one for the Delphi compressor is the 1738, according to the service.citroen.com.

That explains why the belt was hard to remove without removing the eccentric pully; and without compressing the spring, to slip on again. Possibly helped to knacker the tensioner bearing. I'm off to get the right one.


UPDATE: GSF tell me its the 1725 they recommend going by their computer search-list. I tell them citroen tech's listing is 1738, and they agree its best to go with that...their list could be wrong. They offer a 1730 in place of the 1738.

DRIVE BELT
5750 WS K6 - LE 1726 WITH SANDEN COMPRESSOR
5750 YF K6 - LE 1736 WITH HARRISSON COMPRESSOR

gsf 134 bm0130

RIBBELT BELT
E 117 740 K6 1725 WITH SANDEN COMPRESSOR
E 117 741 K6 1738 WITH HARRISSON COMPRESSOR

I take it that the Harrison is the part for the COMPRESSOR DELPHI FRANCE - 1135290. Not sure about why they interchange the name Harrisson with Delphi.

[lexi]

That`s interesting John. I will need to check what belt they sold me .

To answer my question on Crankshaft bonded pulley.........£119 plus vat
from main Stealer

Will you use the 1730?