406 Hdi cold start noise (aux belt off)

[forest aaron]

Hi All,
I'm new to this forum and I'm hoping that someone might be able to point me in the right direction. I've got a 406 HDI 2.0 and I'm getting a squeaking (screeching) noise on cold startup. After a few miles it disappears but I love this car and want to get everything sorted. Below is a small video on youtube I made of the noise and you'll notice I took off the aux belt because I thought it might be the crank pulley but that didn't work.

http://www.youtube.com/watch?v=V7ealLF- ... MzuZ1NIdTw

My thought's are that it might be cambelt rollers but the previous owner had it changed only 26k miles ago and it really sounds like it is coming from the cam gear

Any thoughts will be most welcome in this head scratcher.

[spider]

Welcome.

Would be best to remove the top belt cover at least for a closer look. Going from the noise (I was never that good with noises, someone else may be able to suggest more) , I'm starting to suspect if its not the idler / tension roller it may be the water pump itself.

I take it the belt does not "whine" when you rev the engine ? , that usually points to an overtight belt as most people will do these by feel not with the correct gauge I think. To be fair you can get it spot on via feel once you've done a few anyway.

[CitroJim]

It sounds almost like a scraping noise..

Cambelt area is a good bet and my money is on the belt being incorrectly tensioned. It uses a manually adjusted eccentric tensioner and should ideally be set using a SEEM gauge but you can do it fairly reliably with the old 90 degree twist 'twixt finger and thumb.

Also, are you sure the tensioners and idlers were replaced? It's very important to do so as these are basically little wheels running on ballraces and they do wear.

The noise is a bit reminiscent of a dry bearing.

So, recheck tension and unless you know the tensioner and idler has been replaced, do so. Also it's always a good idea to replace the water pump whenever the cambelt is off so if not, do that too. The noise could well be the water pump too as Andy suggests.

As you love the car and want to be sure, redo the whole job again for peace of mind. I'd do it for peace of mind as although the engines don't suffer too badly if the belt breaks, usually just broken rockers, it's still a lot of trouble and a lot more trouble than a cambelt/roller and water pump replacement.

EDIT: Andy, you and I typing at the same time!!!

[forest aaron]

Thanks for the reply,
I don't get any belt whine when I rev the engine. I'm thinking of maybe going down the route of putting a new cam belt kit on and water pump. It would just be nice to get a few opinions before I do all of that incase it's something else I'm missing.

[MichaelH]

An old trick is a little squirt of water and when you hit the bit that is making the noise either the pitch changes or disapears. (obviously not into the alternator). Don't use oil/WD40 as this will lubricate longer term so you can't re-check (water only has an effect for about 5 mins).

this is not a fix it just finds the location.

The other trick is a long handled screw-driver with handle in your ear and touch blade carefully close to parts (being careful of moving bits). You don't need to put it on bearings etc. as often close enough will do.

Mike

[spider]

Although the WD40 principle is sound in itself, I'd (personally) not want to spray fluid of any kind on a timing belt. An accessories belt is a different matter though, I know on a Citroen it drives the HP which would be a concern if it broke but the principle of lubricating a timing belt I find unsettling.

[lurchy666]

ive got exactly the same noise on my xantia hdi never really thought about it untill i saw this post, mine also disapears after a minute or so of running and dont arrive again untill engine is stone cold,