Speed related buzz

PClarke · 18th May 2009, 15:26

From about 65 and above there is a buzz that appears to come from the face vent area and increases in volume with speed - being very loud at 70+. Pollen filter was split so replaced this hoping that would cure but it hasn't. When travelling on motorway buzzing noise will stop when passing trees/steep banks along side of motorway and start again immediately open again.
Anyone know of a possible cause/ experienced same and cured it?

ragitty · 18th May 2009, 15:39

Just a thought are your plenum tubes sticking out a long way under the car and it is wind related as it passes over the edges of the tube....

baxlin · 18th May 2009, 15:50

Just traced a buzzing on mine that seemed to be coming from the dashboard area, but it turned out to be the front interior roof light come loose. Popped the lens off, tightened the 2 screws, and buzz gone.

Hope yours is as simple.

PClarke · 20th May 2009, 16:38

If only life was that simple - tried both ideas put up so far, to no avail. Still starts up, usually at about 75 and quite loudly, then continues down to about 60 getting quieter as speed reduces and then louder with increasing speed. Horrible cross between buzz and hum as though something is vibrating very quickly. Any help greatly appreciated.

GreyGhost · 20th May 2009, 16:48

This may sound daft but as it happened to me I can vouch for it.
My buzzing was from the interior mirror. Sounded like it was coming from somewhere under the dash. I asked a passenger to locate it for me he found it immediately.
Vibration noises can be tricky. I opened the mirror case and used a very thin bead of silicone sealant on the joint. Problem solved.

uk_dave&gill · 20th May 2009, 17:20

Quote:

Originally Posted by Grey Ghost

This may sound daft but as it happened to me I can vouch for it.
My buzzing was from the interior mirror. Sounded like it was coming from somewhere under the dash. I asked a passenger to locate it for me he found it immediately.
Vibration noises can be tricky. I opened the mirror case and used a very thin bead of silicone sealant on the joint. Problem solved.

Ditto! By fluke I happened to touch the mirror one day whilst the noise was happening and it stopped. Let go, started again etc

I replaced the mirror.........

Tim · 20th May 2009, 18:09

Quote:

Originally Posted by PClarke

From about 65 and above there is a buzz that appears to come from the face vent area and increases in volume with speed - being very loud at 70+. Pollen filter was split so replaced this hoping that would cure but it hasn't. When travelling on motorway buzzing noise will stop when passing trees/steep banks along side of motorway and start again immediately open again.
Anyone know of a possible cause/ experienced same and cured it?

I have exactly the same thing on my R75diesel. Don't think its the mirror (but will check) because I don't get it if the car is wet. Only when dry. Not the tubes as I checked them. Not the chrome trim around the screen. No to bulkhead cover, pollen filter, rubber bonnet bead, rubber bead between screen and bulkhead cover. I've given up keeping below the speed it starts, which is keeping the consumption down

David3807 · 20th May 2009, 19:16

Quote:

Originally Posted by Tim

I have exactly the same thing on my R75diesel. Don't think its the mirror (but will check) because I don't get it if the car is wet. Only when dry. Not the tubes as I checked them. Not the chrome trim around the screen. No to bulkhead cover, pollen filter, rubber bonnet bead, rubber bead between screen and bulkhead cover. I've given up keeping below the speed it starts, which is keeping the consumption down

Think I have seen this one before in a thread - windscreen not sealed/fitted at the bottom properly ?? Does the noise vanish if you use the washers ??? IIRC water (from washers or rain) sealing the gap.

Tim · 20th May 2009, 19:23

Quote:

Originally Posted by David3807

Think I have seen this one before in a thread - windscreen not sealed/fitted at the bottom properly ?? Does the noise vanish if you use the washers ??? IIRC water (from washers or rain) sealing the gap.

Goes in rain or wet conditions wipers don't do anything. For the 35k miles I've done in the car its had the same screen but the 62k before that I don't know.

Thanks for the pointer though, will take the car apart again and mastic the lower section of the screen just to see.

Tim · 5th June 2009, 15:49

Quote:

Originally Posted by David3807

Think I have seen this one before in a thread - windscreen not sealed/fitted at the bottom properly ?? Does the noise vanish if you use the washers ??? IIRC water (from washers or rain) sealing the gap.

Good call David

Took the bits off around the lower half of the screen and silicon mastic sealed the screen. Buzz has gone, pushed the car a few times now and all is well.

18th May 2009, 15:26	#1
PClarke Aged Rover 75 2.5l Club Join Date: Jun 2008 Location: Taunton Posts: 23 Thanks: 0 Thanked 0 Times in 0 Posts	Speed related buzz From about 65 and above there is a buzz that appears to come from the face vent area and increases in volume with speed - being very loud at 70+. Pollen filter was split so replaced this hoping that would cure but it hasn't. When travelling on motorway buzzing noise will stop when passing trees/steep banks along side of motorway and start again immediately open again. Anyone know of a possible cause/ experienced same and cured it?

18th May 2009, 15:39	#2
ragitty I really should get out more....... Jeep Cherokee Orvis Join Date: Oct 2007 Location: Leicester Posts: 2,666 Thanks: 0 Thanked 1 Time in 1 Post	Just a thought are your plenum tubes sticking out a long way under the car and it is wind related as it passes over the edges of the tube.... __________________ [SIGPIC][/SIGPIC]Dance like no-ones watching

18th May 2009, 15:50	#3
baxlin This is my second home Volvo C70 Convertible and JZR 3 wheeler Join Date: Nov 2006 Location: Tring, Herts Posts: 3,960 Thanks: 124 Thanked 173 Times in 124 Posts	Just traced a buzzing on mine that seemed to be coming from the dashboard area, but it turned out to be the front interior roof light come loose. Popped the lens off, tightened the 2 screws, and buzz gone. Hope yours is as simple. __________________ Only my opinion, obviously, so please don’t shoot me if it doesn’t match yours!

20th May 2009, 16:38	#4
PClarke Aged Rover 75 2.5l Club Join Date: Jun 2008 Location: Taunton Posts: 23 Thanks: 0 Thanked 0 Times in 0 Posts	If only life was that simple - tried both ideas put up so far, to no avail. Still starts up, usually at about 75 and quite loudly, then continues down to about 60 getting quieter as speed reduces and then louder with increasing speed. Horrible cross between buzz and hum as though something is vibrating very quickly. Any help greatly appreciated.

20th May 2009, 16:48	#5
GreyGhost Banned 180+ Sport Auto Join Date: Oct 2006 Location: Bedford Middle Level Posts: 17,787 Thanks: 0 Thanked 18 Times in 5 Posts	This may sound daft but as it happened to me I can vouch for it. My buzzing was from the interior mirror. Sounded like it was coming from somewhere under the dash. I asked a passenger to locate it for me he found it immediately. Vibration noises can be tricky. I opened the mirror case and used a very thin bead of silicone sealant on the joint. Problem solved.