Annoying noise from blower

Here's one that's been bugging me for a while...

When the heater/blower controller is set to either the screen demist position or the feet/face position on the dial I get a loud whirring/sucking noise from under the dash. It only does it in those positions, and is completely independent of the blower speed, ie, the noise doesn't increase with blower speed. It does stop when the blower is switched off though. And it's not present with the engine off and the blower running.

When I start the engine I get a couple of seconds grace then this noise starts up.

Having stuck my head out of the door a few times when starting the engine I have found this coincides with a sort of clunk from under the bonnet, rather like when the A/C compressor kicks in, but it doesn't make any odds whether the A/C is switched on or off - the clunk occurs followed by the noise. I am mystified as to what the noise is that's apparently being transmitted through the system, and why only in the two dial positions I've described. Surely if it IS the A/C compressor (or its drive belt), I'd get the symptoms all the time?

That said, if it IS the A/C compressor, why is it kicking in when the A/C is switched off?

Total confusion on this one. Anyone got any ideas?

Cheers,

Craig.

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2002 Freelander Td4

Pollen filter fitted properly?

Kiddies feeding the heater vents sweets/money etc?

If you are needing anything let me know, as I am breaking one at the mo

coz when yu turn demist on, it turns on the air conn - tells ya in ya manual.

If it only happens with recirle on, check up the front left of the passenger foot well.

There may be something stuck in the pipe, thats been sucked up.

I found a carrier bag stuck up in there mine once, after the resistor pack failed. oooooops.

Cheers guys.

I've had the pollen filter out - it looked OK, and went back in OK so I don't think it's that. There may be something stuck in there, but I reckon I'd hear it all the time on every control setting. Could be worth a look though.

We've only got the one lad, and he spends his time in the back of the car so I don't think he's fed anything into the vents!

I'll have a squint at the manual tomorrow, but I had no idea the A/C comes on on the demist setting. Even when the A/C is switched off? Is that true for the feet/face setting too?

Reckon that if what Mad Hat Man says is true then I could have a noisy A/C compressor. Or the drive belt is worn. Can't get that off without taking the serpentine belt off first, can I?

Cheers,

Craig.

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2002 Freelander Td4

You can cut it off to eliminate it if need be, but to replace it you need the big belt off first

Handbook - P64 - half way down......

"Air to foot outlets and windscreen
(if the ambient temperature is approximately 41º F (5º C) or higher, the air conditioning will automatically dehumidify the air to reduce misting).
All air to windscreen
(if the ambient temperature is approximately 41º F (5º C) or higher, the air conditioning will automatically dehumidify the air to reduce misting)."

Have a look in the 4inch diameter tube between the filter housing and fan unit. Make sue the fans if off at the time. I've had water and leaves in mine in there. It's to the right in the pic below.


P4091800 cINQVyx

Thanks for all your replies.

I've had a quick look today, and I'm now definitely sure that it's the A/C making this noise and transmitting it through the blower/vent system somehow. The noise definitely starts when the A/C is either switched on, or comes on automatically in the screen positions.

I'm hoping it is just the belt and not the compressor making the row!

I will dismantle the bits shown in your photoas well, Hippo, as on an 8 year old vehicle, who knows what's lurking in there?!

Craig.

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2002 Freelander Td4

Whoa!!! Try getting it re-gassed first which may relubricate the bearings in the air con. If its been unused for a long time the bearings dry out, especially if gas has run out. Does it get cold when in use? Its recommended to be run A/C for about 30 mins every 6 months or so to keep it lubed up.

I did re-gas the A/C system about three months ago as it wasn't functioning at all. I put some system sealer/seal revitaliser in there as well as refrigerant. I'm sure the noise started up shortly after that, thinking about it.

The A/C is now working less well, so I assume I have a sizeable leak somewhere.

Curiously enough the noise has all-but ceased today. Perhaps talking about it has somehow mystically healed it ?

More likely the A/C gas pressure has now dropped to a point where the compressor won't bother doing anything when it's supposedly switched on. I believe I'm correct in saying that the compressor clutch won't enable if there's not enough gas in the system?

At least it's gone quiet. I can live without the A/C for now...

Hi there.

Did you find out what was causing the noise, as my 2003 td4 has just started with exactly them same fault. On the demist setting only, theres a vibrating knocking noise from engine bay. Any feedback will be a great help.

the wife

fanatic said:

the wife

Click to expand...

:hysterically_laughi

fanatic said:

the wife

Click to expand...

No, that's the annoying whine from the passenger seat.