Clunking noise and auxiliary belt

Napolian · Unread post by **Napolian** » 03 Jun 2011, 11:14

Clunking noise and auxiliary belt

Hi, I am puzzled about my trustee Xantia 1.9td (AC) failing yesterday. Suddenly there became a clanking noise from the engine. On inspection the auxiliary belt was shredding. The AA man was also puzzled as it “could be the big-end shells” or it “could be the timing belt assembly”. I can’t understand what the connection would be in order to shred the auxiliary belt. The cost of such engine repairs seem to be horrendous so any pointers will be greatly received.

jgra1 · Unread post by **jgra1** » 03 Jun 2011, 11:37

As you will need a new one anyway, I think I would cut the aux belt off and check all of the pulleys and idlers first? one must be loose causing the noise and the shred?
Could be the AC pump ?

i cant see how the big ends can be connected to be honest..

steelcityuk · Unread post by **steelcityuk** » 03 Jun 2011, 11:39

This is a shot in the dark but on some PSA cars the crankshaft pulley is also a damper. It has a inner part and an outer part bonded together with a rubber compound, this compound can disintegrate which allows the outer rim to move in ways it shouldn't with the consequence that it can shred belts, make screeching or rattling noises.

Check this first.

Steve.

Napolian · Unread post by **Napolian** » 13 Jun 2011, 17:45

Thank you for your replies.

On making an inspection it appears that the auxiliary belt has shredded and some of it got trapped under the cam-belt causing it to slip. Both were changed three years ago according the previous owner’s garage bill!

There is no doubt valve damage so the car will have to stay off the road until I have time to repair it. The local garage wants £1200 for doing it. (unless someone knows a cheaper garage in Hampshire).

Unread post by **CitroJim** » 13 Jun 2011, 18:09

steelcityuk wrote:consequence that it can shred belts, make screeching or rattling noises.

Check this first.

Absolutely, and then after that the automatic tensioner. Check it is smooth and free in its operation and the jockey wheel is not cocked up at an angle. Often the needle roller bearings fail inside it or the pivot bolt shears.

You may be lucky with the valves. Replace the campbelt, retime it and cross fingers. As the valves are perpendicular to the pistons, they often escape unscathed. The noise may not be the valves at all, just a diesel knock from being off-time.