new auxiliary drivebelt noise

[lazza]

HI Forum

Have successfully changed crankshaft pulley, auxiliary drivebelt and change the 3 way coolant pipe from the bottom of the radiator. All ready for big trip to france this week.

One thing- the new auxiliary drivebelt, exactly same number/model as the last one, makes a squeeling sound for the first 5 minutes or so. Then it seems to settle down.

Is the automatic tensioner not working correctly?
Is this normal wearing in process?

Thanks
Larry

[Xantidote]

Larry, I've no knowledge of the auto-tensioner as mine has a manual tensioner, but I can't believe there should be any "wearing in process".

If the squealing disappears after about 5 minutes, this could be when the load on the belt, due to alternator recharging the battery, has reduced.

Does squealing still happen if you restart the engine after (say) 5 minutes. On the 2nd start-up, engine presumably fires instantly, therefore taking less out of the battery. Condition of tensioner pulley bearing OK?

[xantia_v6]

It is possible that one or more of your pulleys is worn such that the belt is not gripping properly. On ribbed belt systems, this usually shows up as the bottom of the valleys in the pully looking a little bit rounded, rather than sharp (the belt gets it grip from the sides of the valleys, not the peaks and troughs).

Oil contamination of the belt may also cause this squeaking, so you could try washing the belt and pulleys with a strong detergent solution (and rinse).

[CitroJim]

Hi Larry, I'll stick my neck right out here and say the problem is with the automatic tensioner. Check for a big spring begind your hydrauulic pump. If you have one, a 96 on aircon cars do, then that is the prime suspect. The tensioner pivot is a set of needle rollers working on a steel sleeve. Over time the rollers break up and dig into the sleeve, restricting the smooth motion of the tensiner and makings the belt slack as it has a habit of jamming in the fully slack position.

Another point to bear in mind is that there are two belts sizes specificed, depending on the AC compressor fitted. A 1723 or 1735 (I think) but in any case a big difference in length. If the belt slipped on easily then it's too long and you need the shorter one. The longer one appears to tension but will rattle and squeal like a good 'un.

I posted a stem by step guide to replacing the tensioner a while back. I'll go find it if you have no success in finding it...

[lazza]

This is a tricky one

I cant see any spring behind the hydraulic pump. All I can see is the arm for the pulley.

When it first went on the pulley jumped back and forwards quite violently then settled down.

The number of the belt was exactly the same as the last one, and in the parts shop i asked for the "with aircon" size.

The only changed part is the crankshaft pulley. Could that be dodgy? it is not a citroen original part.

The problem is that the manual tensioner is already at its maximum as it was for the last belt.

So i'm a bit stumped.. here at the end of the album are some pictures I took with the old belt off: http://picasaweb.google.es/larryparker2/Xantia

Thanks

Larry

[CitroJim]

Larry, you have the earlier manual tensioner there. That's a good thing actually. Disregard all I said about the automatic one.

Now, if the adjustable part is at the end of its adjustment with the new belt as it is in picture 51 then the belt is too long for your particular set-up. I wonder if the parts supplier has given you a belt for the later automatic tensioner models. These do use a different size belt.

I'd be tempted to go back to the supplier and look for a belt that is shorter. You can tell their lengths by the code on them. For instance, a 6PK1625 is a 6 groove belt 1625mm in length. Try one 15mm shorther for starters and go from there. Maybe the supplier will allow you to borrow a selection and take one that fits best. Aim to get the tensioner adjusted so the correct tension is achieved near the other end of the slot.

It may be that the new crank pulley is a little smaller in diamater then the old perhaps although I'd be surprised if it was even being an after-market one.

Posting the picture was remarkably helpful Larry

[bxman]

I think you will find that you need a shorter belt probably only 15-20 mm.

As to the idler pulley I have found 2 out of 3 of the tensioner's to have been seized-up .
My 1.8 16v developed a squeak within the last fortnight and you post encouraged me to investigate this afternoon.
I found that my belt had worn to the extent that it was now longer within the range where the tensioner was exerting any pressure on the belt.
Fortunately the spring was still free as I mentioned all other occasions I have needed to free the spring off which is quite a lengthy process.

I know there are a whole range of marginally different belt lengths.

With mine the squeal was only on tick-over and dis-appeared with an increase in revs.
This is because the wrap around the alternator pulley is not that great and the torque load on the alternator pulley reduces with the increase in revolutions.
Good luck and keep us posted.
Patrick

assorted old xantia

[lazza]

HI

Cheers for the replies

Yes seems like it needs a shorter belt. I will get one or two different sizes tomorrow and try to fit them.

Still a bit confused though, because according to Haynes, my set up has both a manual adjuster and an automatic adjuster (the one i have to put a rod in the back of when i'm slackening the belt for removal)

Can anyone enlighten me on whether mine is manual or automatic??

Thanks again- lets hope i can get this sorted for thursday when I'm supposed to be setting off
Larry

[Xaccers]

The automatic one normally has a manual excentric one lower down, with a hex bolt keeping it on the engine and a square hole next to it to adjust.

If memory serves, you leave the excentric one slack and able to move, then remove the locking rod from the spring loaded auto one, then tighten the excentric.
Just a thought, have you slackened the excentric one?
That could stop you fitting the right length belt if you haven't

[CitroJim]

Larry,

Going on the pictures, you have the standard early A/C manual tensioner set-up, the one that Haynes describe for the 1.9TD in the Xantia BoL. What they call the 2.1TD setup in the picture next to it is in fact the later automatic tensioner with the eccentric pulley and big spring tensioner also fitted to later 1.9TDs.

To show the essential difference, have a look at these diagrams.

This is yours:



Whereas this is the later automatic tensioner:

[lazza]

HI

Yes that's right I have the top diagram. Therefore guess I'm manual

Funny thing, is I went into Citroen this morning and they said i should definitely have the 6PK1736 belt, and saying my pulleys must be worn... yet the picture they showed me was the 2nd one you have posted!

There was another size 6PK1726 recommended for Sarten aircon instead of Harrison, but I have Harrison... so it's all quite confusing

Anyway to make a decision, I went to a spare parts place and have got a 6PK1725 ... hoping that this will make the difference.


Cheers
Larry