Weird Motor Sound from Radio

[alisan]

Hello everybody,

According to my experiences, my 2011 c5 x7 tourer has some weird noise when I try to listen music only from bluetooth or aux mode. When I press the gas pedal parallel to the rev increase there is some noise coming from the speakers whether music is playing or not. I think it may caused because of bad grounding. The car has its original sound system no upgrades. Anybody faced with the same issue? Thanks in advance

[GiveMeABreak]

This can generally be an earth issue and more commonly found when fitting aftermarket kits when they have been wired in badly. You could try checking the earth point or fit a noise suppression unit to get rid of it.

[alisan]

This can generally be an earth issue and more commonly found when fitting aftermarket kits when they have been wired in badly. You could try checking the earth point or fit a noise suppression unit to get rid of it.

First of all thank you for your answer. There is no aftermarket kit added to the ca everything is original actually. Could please explain where the earth point is and how to install supression unit?

[white exec]

If the 'motor' interference is only on RADIO/TUNER setting, it could be noise coming in via the aerial. Important that the antenna/aerial lead gets a good ground connection, at both radio (head unit) end and at the roof/mounting point.

If the noise is on other inputs too (eg CD, USB...) then the issue is probably poor Grounding. First action is to make really good Ground connection (ok to make an additional one) between radio/head unit chassis/case and a good Gnd point nearby.

Possible, although less likely, is that the +12 feeds to the radio have been taken from frail/noisy sources, rather than from good wiring. If this is the case, it would show up on whichever input the radio is switched to.

If the noise is only there when the engine is running, it is either an IGN (if petrol) or alternator problem.

>> Mark and I seem to be replying almost simultaneously, so no shortage of advice!

[GiveMeABreak]

First you need to work out the likely cause:

1) Test the Radio first - can you here the whine increase with the engine speed increase?
2) Now change to CD source or Bluetooth Streaming. Can you still hear the same whining noise?

If the noise is only on the radio, then the fault is likely a poor earth from the aerial - so check the earthing points.
If the noise still continues on all sources, then it is likely to be from the alternator. As the engine speed increases, so does the alternator which is why you hear the increase in whining from the speakers.

So if this is the case, then I would check out the alternator earth and make sure it is making good contact with the body / clean it up. If it is still not helping, then you may need to fit a noise suppressor in between the battery positive lead that goes to the alternator.

[alisan]

If the 'motor' interference is only on RADIO/TUNER setting, it could be noise coming in via the aerial. Important that the antenna/aerial lead gets a good ground connection, at both radio (head unit) end and at the roof/mounting point.

If the noise is on other inputs too (eg CD, USB...) then the issue is probably poor Grounding. First action is to make really good Ground connection (ok to make an additional one) between radio/head unit chassis/case and a good Gnd point nearby.

Possible, although less likely, is that the +12 feeds to the radio have been taken from frail/noisy sources, rather than from good wiring. If this is the case, it would show up on whichever input the radio is switched to.

If the noise is only there when the engine is running, it is either an IGN (if petrol) or alternator problem.

>> Mark and I seem to be replying almost simultaneously, so no shortage of advice!

Thank you for your answer. The noise comes only when the inputs AUX and bluetooth is selected. I will search for a grounding point to make extra ground connection

[alisan]

First you need to work out the likely cause:

1) Test the Radio first - can you here the whine increase with the engine speed increase?
2) Now change to CD source or Bluetooth Streaming. Can you still hear the same whining noise?

If the noise is only on the radio, then the fault is likely a poor earth from the aerial - so check the earthing points.
If the noise still continues on all sources, then it is likely to be from the alternator. As the engine speed increases, so does the alternator which is why you hear the increase in whining from the speakers.

So if this is the case, then I would check out the alternator earth and make sure it is making good contact with the body / clean it up. If it is still not helping, then you may need to fit a noise suppressor in between the battery positive lead that goes to the alternator.

Hello, as I said in previous quote the noise is not coming when radio is selected. I will also check the alternator grounding. Thank you!