What's the squeal?

[Janey]

Can anyone tell me what these symptoms could mean? (V REG 406 estate HDi 2ltr)
When the 406 is warmed up, say after 10miles, there's is an intermittent high pitched squeal/squeak. Can be constant when driving straight line, usually occurs above 40mph, the noise seems louder when the steering wheel is turned even slightly to the left and it seems to me as if the noise is coming from the drivers side at the front. More clues? the noise is not affected by braking /accelerating / gear change.

I've cleaned the brake pads thinking it could have been all the grit and crap, but this hasn't sorted the noise. We still made it from North Wales to London no probs yesterday, couldn't hear it if i turned the radio up.

(Recent history, full service in dec 12. suspected water damage to pistons in jan13 - turned out that engine is ok. leaking coolant housing pipe last week, plugged up n fine now. But this squeal did start about the same time as the coolant light came on, coincidence?)

I'm stumped, as in my mechanic.

Slippy belt? steering fluid? bearings or joints? very angry mouse stuck under the bonnet?

But you guys know your 406s right? Any help appreciated.

Janey

[lozz]

My guess wouid be Aux belt, or something it runs with, Ie Tensioner/pulley,
iwouid check the tension on the belt and the condition of it,

[gumby6371]

Hi Janey,

As Lozz says it will be something on the aux belt, I'd take the belt off and check all pulleys and idlers for play or roughness.
Quite a bit of stuff running off that belt and if it snaps it can take the cam belt with it.

Don't refit the same belt, there not pricey and it's not wise to re-use them.

[Ares]

Yes i agree,aux belt or something connected with it.
My car does the same sounds...its like a metal high sound,upon turning steering wheel it tends to get louder.

[gumby6371]

Turning the steering puts extra pressure on the belt/idlers/pulleys as the power steering is working but that doesn't mean it's the power steering making the noise, the extra tension is spread all over the belt making any weak points complain about it.

[Doggy]

Could be the dual mass crank pulley that drives the aux. belt - if it is you will usually find rust deposits or metal filings in the surrounding area

[Janey]

Excellent, Thanks so much, that saves so much hassle investigating.

I'll get onto checking it out as soon as poss.

Am I doing any damage driving around with it like this for a few days? (I haven't really got much choice, i need it for work)

[steve_earwig]

Not necessarily doing any damage but if the belt fails or the pulley disintegrates the belt could end up inside the timing belt cover and take out the timing belt, with not very hilarious consequences. Best investigated as soon as, once you know what it actually is you'll be better placed to know how urgent it is.

[teamster1975]

The alternator seems to be a common squealer, I had to change mine for the same reason.
Try using an extension bar as a sounder to isolate the noise or as the others say whip the belt off and spin everything by hand.