C5 Clunking And Revs Dropping Off

[stephenhoughton]

Hello

my wife recently had the timing belt replace don her c5 2.2 hd vtr+

the car has 100 000 miles on it

Now thee is a clunking from the nsf when he revs reach 1000 rpm.

when she changes gears the revs drop immediately from 2000 - 2500 to less than 500.

Anybody got any ideas what the issuers are and how to put them right.

The car runs but she has noticed hese differernces since the timing belt work was done

 

 

[paul.h]

You could have a look at the crankshaft pulley to see if it is falling apart. It has a rubber insert that can perish. Have a look at this http://www.citroen-owners-club.co.uk/citroen/topic/20707-c5-knocking-when-cold-crankshaft-pulley/

Otherwise if the belt/tensioner has not been fitted properly it should go back to the garage that did it, provided it is related to engine revs and not road speed when moving i.e. it does it when stationary. If only when moving it could be a suspension problem. Also see if it only does it when the air con is being used - it clunks as the compressor clutch pulls in and out and is normal.

[stephenhoughton]

hanks Paul,

the car sounds and seems to run normally.

The clunking is a metallic thud that seems to come from the nsf

recently had tracking done, the clunking was presnt before the tracking was done.

The garage guy heard the clunk, checked all around the wheel tie rod etc and could find nothing to cause the clunk.

The rev issue has happened since the timing belt was changed

[paul.h]

Are you sure the clunk is from revs on the engine or when moving ? Was the tracking adjusted due to bad tyre wear which could have indicated worn suspension parts ?

 

I had a clunking on a C3 when slowly going over bumps and that was a worn tie rod. Other suspension causes of clunking can include the ball joint at the bottom of the suspension swivel, suspension wishbone arm worn bushes, worn steering - mountings or track rod ends, a worn wheel bearing (although more likely to whine), loose/worn away brake pads or if when turning a cv joint, worn subframe bushes.

 

If it makes the clunk when stationary when you take the revs to 1000 rpm, try it with the bonnet up and see if something is loose, such as the driver side engine mounting which would have been removed when the belt was replaced. If the clunk is more from the back of the engine it could be the rear mounting suffered when the side one was removed.  Check round the battery area since that may have been disconnected. Also check the wheel bolts are tight - the wheel will have been removed.

 

Still check the crankshaft pulley. The retaining bolt has thread lock on it that makes removal difficult and a risk of snapping the bolt. An impact wrench should not be used but a wrench to undo/do up and repeat until the bolt is removed. If the torque goes up to 200 Nm doing this then heat is supposed to be used to soften the thread lock but not too much such that the pulley rubber suffers.

 

The revs dropping could be the belt has been fitted a tooth out or maybe a pipe has not been reconnected near the engine mounting.

 

Was it a dealer/garage that replaced the timing belt ? There should be a guarantee of the work so you can take it back.

[stephenhoughton]

To let you know the answer to the problem was the garage.

The car was taken back to the garage on 27 december.

The belt was checked, there was a loose mounting / strengthening bar that explained the clunking.

When the car was returned, there is no clunking and the revs indicate normal, dip slightly on changing gear and do not drop off to almost nothing anymore.

The garage put right what they missed during the belt change, at least they did not try to cahrge for puting it right.

Thanks for all the replies

 

Stephen