Heater matrix fan?

[saucyboy]

Hi guys,

I have just started to get an annoying noise from my heater matrix fan at motorway speeds.

If I accelerate I get a kind of droning noise from the heater fan. If I turn the speed dial to full or into recurc it stops. I have noted that it does not happen every time.

Has any one got any ideas what the problem is or has any one else experienced the same problem?

Cheers

Jim

P.S. Joust, If I recallcorrectly you recently visited Monkey World. I can highly recommend visiting the wild mountain Gorillas in Rwanda as I have just got back and it was one of the best experiences of my life so far!!

[joust]

I'll bear that in mind.

Does the noise happen when you are only accelerating, or at a constant speed? If I read your post right it makes a noise when the fans are off, not when they are on?

J

[saucyboy]

Hi mate,

It happens when they are on and accelerating. But this can be a slight acceleration when at motorway speeds.

Turning the speed dial stops it but then it can returns if accelerating again (Obviously the air rushing through the system from outside). It's wierd as didn't happen on a journey of 20 miles yesterday morning and then started again upon my return later that day.

James

[joust]

That is weirder than a very weird thing!

Err - not a clue!

J

[EpsomJames]

saucyboy said:

If I accelerate I get a kind of droning noise from the heater fan.

Are you sure it's from the heater matrix fan?

I get something similar when accelerating...but it's from my passengers...and come to think of it, it's more like a kind of an "ARRRRGGHH" noise.

Edited by EpsomJames on Monday 16th October 13:43

[robp]

Had something similar, but the noise was only evident when the dial was turned in the 'fresh-air' half and it only occurred at >80mph (on the autobahn obviously). Put the switch into 'recyling' mode and the noise just disappeared. Magic. No idea what was going on, but now I just use the fan on the 'recycle air' side and no probs.

[AMG Merc]

robp said:

now I just use the fan on the 'recycle air' side and no probs.

Rob, do you mean 'recirc' - if so this is generally unhealthy as a permanent setting (as born out by the fact that all modern climate control systems revert back to 'outside vents open' mode at the next engine start to avoid inhaling the cabin air for long periods.

[robp]

Oh and whilst on the subject of weird noises from the front end, I've recently found a 'phissling' noise from around the heater matrix area when the car is stationary and with everything switched off. I removed cap from header tank to see if reducing pressure helped - it didn't. Disconnected the battery to ensure it wasn't an electrical fault - it wasn't. So what's left? Air-con condenser? If all my gas was escaping the air-con wouldn't work - it does.
Tres mysterious
Any ideas?

[ACROWE]

robp said:

Had something similar, but the noise was only evident when the dial was turned in the 'fresh-air' half and it only occurred at >80mph (on the autobahn obviously). Put the switch into 'recyling' mode and the noise just disappeared. Magic. No idea what was going on, but now I just use the fan on the 'recycle air' side and no probs.

It is something to do with the pressure inside the cabin. If you push the window when driving at speed the noise will go away. It seems to be a feature of the cars, as everyone I have driven does the same. As robp says, set the fan into 'recycling' and it goes away. Either that or get a louder exhaust.

[saucyboy]

Robp, My noise had also stopped whilst switched to recirc.

However, I will be trying to solve the problem. Has anyone got any ideas in respect of gaining access to the fan? A friend has suggested that something (Leaf etc)may have blown in.

James

[robp]

AMG Merc said:

Rob, do you mean 'recirc' - if so this is generally unhealthy as a permanent setting (as born out by the fact that all modern climate control systems revert back to 'outside vents open' mode at the next engine start to avoid inhaling the cabin air for long periods.

'Modern climate control systems' and 'Noble' -in the same sentence?
Theoretically you're right Rob, but usually applies to the hermetically sealed uberwagons. My P&J is anything but hermetically sealed and I don't seem to have suffered too many ill effects (debateable I know) after 2 yrs of this.

[AMG Merc]

robp said:

My P&J is anything but hermetically sealed and I don't seem to have suffered too many ill effects (debateable I know) after 2 yrs of this.

Right, you mean that Joker grin "ill effect"! Having everything shut to the outside world does seem to create a lot of pressure inside a Noble cabin.

[gadgeroonie]

its probably a leaf in there somewhere - or one of the hoses to the vents has come loose

if you look under the dash - you can see where the hoses meet up

i had a kind of rattle a while back - turns out a stone had got caught underneath the front clam !

[joust]

robp said:

Had something similar, but the noise was only evident when the dial was turned in the 'fresh-air' half and it only occurred at >80mph (on the autobahn obviously). Put the switch into 'recyling' mode and the noise just disappeared. Magic. No idea what was going on, but now I just use the fan on the 'recycle air' side and no probs.

That's the air escaping through the window seals.

If you pump air in from the outside it has to get out somewhere, and it finds it way out of the window seals. It's not helped by the aero's of the M12 body which makes a low pressure area next to the windows.

Putting it onto recirc means there isn't an air pressure difference between inside and outside.

J

[robp]

Cheers J. Makes good sense (as always).
Any ideas on the 'phissling' noise from front of car? It's still going 3 days after the car was last used.

[AMG Merc]

Funny no one has mentioned Lee Noble's quote in the current issue of Car Magazine (page 25):

"Making a car fast is relatively easy: making it's doors seal properly is near impossible"

[robp]

AMG Merc said:

Funny no one has mentioned Lee Noble's quote in the current issue of Car Magazine (page 25):

"Making a car fast is relatively easy: making it's doors seal properly is near impossible"

LOL

[Timbo_Mint]

robp said:

Cheers J. Makes good sense (as always).
Any ideas on the 'phissling' noise from front of car? It's still going 3 days after the car was last used.

You've not got a nest of less spotted Phisser's in the fna housing.... Billy Oddie could help then!

Cab't help you on the noice

Talking of fans on all the pictures I've seen of the M12 the window blower cover are closed is this because, as I've discovered they seem to mist up the window more than clear it and thus it best to keep them close?

[robp]

robp said:

Oh and whilst on the subject of weird noises from the front end, I've recently found a 'phissling' noise from around the heater matrix area when the car is stationary and with everything switched off. I removed cap from header tank to see if reducing pressure helped - it didn't. Disconnected the battery to ensure it wasn't an electrical fault - it wasn't. So what's left? Air-con condenser? If all my gas was escaping the air-con wouldn't work - it does.
Tres mysterious
Any ideas?

Turned out to be a knackered alarm unit!!

[AMG Merc]

robp said:

robp said:

Oh and whilst on the subject of weird noises from the front end, I've recently found a 'phissling' noise from around the heater matrix area when the car is stationary and with everything switched off. I removed cap from header tank to see if reducing pressure helped - it didn't. Disconnected the battery to ensure it wasn't an electrical fault - it wasn't. So what's left? Air-con condenser? If all my gas was escaping the air-con wouldn't work - it does.
Tres mysterious
Any ideas?

Turned out to be a knackered alarm unit!!

Ha, Ha - reminds me of the time the radio was chirping away for some reason - had me looking and listening everywhere for it!