CitroJim's Citroens

[captainhaddock]

Glad you like the C1. Now here's a nice mystery for you:

http://www.youtube.com/watch?v=hHMTqBCD ... e=youtu.be

The guy that bought this V6 XM, had it looked at by experts and had the gear box and torque converter changed. And really seriously looked at it, even using microphones! They now think it must be the engine. Of course there's more details....but it's got them all stumped for now...

[xantia_v6]

It sounds to me like a cracked flex plate.

[captainhaddock]

What is a cracked flexplate?

[Dean]

Its a coupling plate the torque converter bolts to which in turn is then bolted to the flywheel, its a fairly high stress item and if broken completely would result in total loss of drive and an awefull noise to say the least, if its cracked it would make a noise like..........................well, the one in the video.

D

[captainhaddock]

Thanks Dean! I would think it should have shown when they changed the torque converter and gear box? Is it easily visable??

[Dean]

It is if your looking for it, usualy it would stay attached to the flywheel and the torque converter would just be unbolted from it so yes it would be in plain sight but if they were not looking for it and just got the box out and put the new one back in in a hurry it could of been missed, only one way to check it though........................gearbox out!

D

[xantia_v6]

The spring part of the plate is riveted to a boss tat is bolted onto the crankshaft. they usually crack in a circle from rivet hole to rivet hole, with the rivet heads preventing total disintegration. Easy to miss unless you look for it. I have seen and heard it once, several professional mechanics were unable to correctly diagnose the noise.

[captainhaddock]

OK, but the flywheel has been changed as well as the torque convertor and gearbox itself. The sound on the youtube film is in reality not as loud as it seems. It was tried to see if the sound would occur with the hydraulics disconnected. It didn't go away. However, the sound disappears when switching off the engine whilst turning the car to the right.

[Jan-hendrik]

However, the sound disappears when switching off the engine whilst turning the car to the right.

Not much to go on with a 20 sec video. What happens when killing the engine in a left turn, or running straight ahead, or reversing any way you like?

[captainhaddock]

I've asked your question. I would think Dean and Xantia V6 's possible solutions are very likely. But how likely is it to miss this break in 2 plates or did they swap back the old plate by mistake or what, I don't know. I've suggested to the owner to join our forum, since he knows what' s happened in detail. I was merely trying to think with him but it is not something I know anything about really. It needs another topic as well, sorry Jim!