Loud whining noise behind centre dash / back of engine bay?

[Zip]

All,

About 3 days ago, I started to get a rhythmic highish pitched, and loud, whining noise behind the central dash. It's constant, kicking in a few seconds after engine start.

It is not linked to engine speed or HVAC blower motor speed at all. Just a constant, and bloody annoying, noise. On cruise control somewhere north of the national speed limit, with radio on, it's still very prominent.

What's down at the back of the engine that could be making that? Anything down there that could be rubbing / bearings going? Anything under the dash doing the same?:Confused:

Very odd.

Thanks in advance,
Z

[HPsauce]

99% auxiliary coolant pump motor.
Not sure how vital they are in D3's but I've had to "kill" them in both of my D2's with minimal effects other than quiet..

D3 looks like this, pump motor on the left:

[Zip]

99% auxiliary coolant pump motor.
Not sure how vital they are in D3's but I've had to "kill" them in both of my D2's with minimal effects other than quiet..

D3 looks like this, pump motor on the left:

I assume you mean by "kill" that the car will happily operate without them...?? Do they have their own fuse? Where are they - easily accessible?? Why is there an auxiliary pump at all???

questions questions questions.....:-(

Zip

[HPsauce]

Used to supplement to flow of coolant into the HVAC for cabin heating and required for the "rest" function to work.
On a D2 you just press the "rest" button (ventilation/heating with engine off) and if it's that pump you'll hear it. On D3's I think you operate it a bit differently, but that's the acid test.

Don't know about D3, but again on D2 without it it takes a little longer on cold days to warm the cabin as the coolant flow is dictated by the main engine water pump and the valves in that unit; no extra diversion power for flow via the HVAC due to the pump and probably a bit of a blockage.

Never been a problem though.

On PF D2 the plug on the flylead for the pump is very accessible under the bonnet, on FL D2 I just traced the relevant wires to cut, though later found the likely plug under the central air intake meshed cover. D3 no idea where the pump leads run or how accessible they are.

[Zip]

Used to supplement to flow of coolant into the HVAC for cabin heating and required for the "rest" function to work.
On a D2 you just press the "rest" button (ventilation/heating with engine off) and if it's that pump you'll hear it. On D3's I think you operate it a bit differently, but that's the acid test.

Don't know about D3, but again on D2 without it it takes a little longer on cold days to warm the cabin as the coolant flow is dictated by the main engine water pump and the valves in that unit; no extra diversion power for flow via the HVAC due to the pump and probably a bit of a blockage.

Never been a problem though.

On PF D2 the plug on the flylead for the pump is very accessible under the bonnet, on FL D2 I just traced the relevant wires to cut, though later found the likely plug under the central air intake meshed cover. D3 no idea where the pump leads run or how accessible they are.

Thanks HP - found your thread from this time last year.

Looks like you can replace just the pump, and not the valves themselves...? Seen our sponsors are selling the valve assembly independent of the pump. I'll check the "rest" function later.

Can I get the motor off through the back of the glove box, as IT suggests? Need to stop this noise...
Z

[Zip]

OK - confirmed it is the pump doing the "rest" test last night. Am I hearing the bearings on the impellor on the pump screaming, or the motor itself...? I presume if it's on the impellor, the whole lot needs swapping?

Either way, anyone had the joy, or worked out how to replace it?

Thanks for your advice in advance!

Z

[Zip]

Any more advice on this please? How do I get to it / swap it out? Driving me mad.:mad:

Zip

[HPsauce]

Just disconnect it as I pointed out (and you quoted) ;)

[johnny_quattro]

http://forum.a8parts.co.uk/showthread.php?p=56722#post56722

I took some photos after experiencing the same loud(ish) noise. Hopefully this helps.

Cheers,
John G

[HPsauce]

Funny thing is my PF S8 had the connector there, but the FL didn't so I cut the wires (and sealed appropriately).
Later found what was "probably" the relevant connector under the central air intake mesh.

[Zip]

Thanks all.....I'll have a look when it warms up a bit...

Z

[Zip]

Right...while I'm not tackling dodgy sunroofs and temperature sensors, I'm back on to the noisy auxiliary pump thingy...

So......I DON'T have 2 plugs (one purple, and one beige). I just have the beige one, but can see the electrical connector to the pump down the back. Will be another exceptional ball ache to get that one decoupled, and somewhere between Bob and no hope of ever getting it back in again.

What happens if I disconnect the beige one......?:p

Falling out of love with my car at the moment....:-(

Z

[HPsauce]

Well just do the "Rest" thing and disconnect that plug, see if the noise stops.
If not take the air intake cover off and do the same with the connector under there.
Report back.....

[Dezzy]

I've never had to touch mine (yet) but if you don't have elbows that hinge both ways and arms that can reduce in diameter then i think taking the intake manifold off will make access easier.
Someone will surely have a copy of the procedure they'd kindly post up for you.

[Zip]

Aarrrgghhh!!, can't get the plug off the side of the motor. I will probably be cutting the wires and crimping a couple of bullet connectors on the ends 'just in case'. There are 2 plugs under the 2 flaps on top of the blower motor, but cant get to them anyway.

Properly fed up......:-(

Z