shamrock

For the benefit of the seach cops , I've done one without result!!

I've noticed a new sound these last few weeks , a low 'whistling' sound at between 2-3k revs coming from the engine compartment . Checking the oil yesterday , I could still just about hear it at idle , and I believe it's coming from the heater blower (when I cover the aperature with my hand the sound disappears!) ..
Has anyone else had this before .. Is it the heralding of a blower heading towards the great bearing scrapyard in the sky!!?

Can the unit be opened up for investigation or is there little point as my search suggests the only the complete unit is available if it needs to be replaced? I'd appreciate if anyone had blower diagnostic/DIY info , there's no mention on p.car / workshop that I could find.

ETA , whoops , just seached 'blower' rather than 'heater blower' and have some up with more threads .. Will scan thru these ASAP and report back!

shamrock

Nope!
Talk of 'squealing' blower motor in other threads, but this is much more a vague whistling sound , most apparent between about 2 and 3k revs..

air leak??

Texas993

I bet it is the belt sensor...

VNTGSPD

Does it do it with the temp sensor on the CCU turned to full cold? I noticed that when I turn up the heat, I can begin to hear the what sounds like the blower motor turning. I think this is just the flaps opening and allowing the airflow through the system. This could be causing the blower motor to turn from the airflow caused by the engine cooling fan. But, in my case I don't recall being able to hear the fan motor over the sound of the mufflers (unless the CCU fan switch is turned on).

shamrock

Good point , I'll try it on full cold and see.. ould be one of those things where it always existed but my ear has suddenly become tuned to it.

I'm fairly sure it's not the belt sensor , it's not a round you'd associate with squeaking , more sound of air thru a gap!?

Davies

Have you checked whether your fresh air flap servo is functioning? It's a pretty common failure and can cause the whistling symptoms you describe.

shamrock

I haven't checked this Matt .. How do I go about this , and could you describe any other symptoms?

I've noticed that on longer journeys when I'm cruising over a long period (say an hour or more) that I have to keep turning the temp up (nearly to red dot) in order to get heat into the passenger area
.. I assumed this was part of my cars 'charm' but maybe it's a connected symptom in some way?

Davies

Do a search and there's some good write ups (better than I can provide) on it.

I don't know about your heat issue, though an easy way to tell if your fresh air flap is closed is if you push the recirculation button and get a sudden burst of good airflow from the vents. Without fresh air the system labors for well, fresh air, and wheezes/whistles. Recirculation bypasses that.

You can check the fresh air flap itself if you pop the bonnet, and remove the plastic cowl above the firewall. There's three servos that respond to sliding the HVAC buttons back and fore. Fresh air is IIRC the middle one.

shamrock

Thanks very mch Matt , that's loads to work on!

roddylennox

Did anyone find the cause of this problem? I've got the same...whistle from throttle body area on light acceleration only. Spraying carb cleaner in the area does not affect revs, suggesting no air leak.

You can even hear it with the car stationery if revved gently - a little whistle from throttle body area.

Thanks