High pitched Radio noise

This noise is driving me crazy!!! I have a 2000 Golf TDI with 235k and i figure it must be the speakers that have this high pitched noise coming from them.

Even when the radio is playing all you can hear is the high pitch in the background. Even when I turn the radio off the sound is still there.

I'm pretty sure it has to do with a bad ground or something but where do I start. Or do I replace the whole deck? Will that solve the problem?

Does anyone else Have this?

The car has a Factory tape deck with a factory installed panasonic 6 disk changer in the back.

And I allready did a search on old topics and came out with no useful info.

Thanks

It's NOT the speakers. Speakers cannot make sound without power applied to them by some external power source. It sounds like the amplifier chip in the radio head has gone squirrely--a VERY common problem in virtually every system that uses those stupid things--and most these days do use them. You'll want to check and see if your car's system uses an additional amplifier external to the radio head. If it does, the problem could be there and that will complicate troubleshooting.

The following is based on my years of warranty experience with OEM car audio systems. While I have no direct experience with VW systems, pretty much all systems operate the same on a nominal level with the biggest differences among carmakers being data communication formats. It is extremely unlikely that this failure has anything to do with a data bus, IMO. Here goes:

If you have an external amp, pull the fuse for the radio head (it should be separate from the amp fuse) and see if the noise goes away. If it doesn't, the amp is the culprit. If it does go away, the culprit is *probably* the radio head.

If you don't have an external amplifier, just change the radio out. The fact that the noise doesn't go away with the radio shut off says to me that there is something awry in the audio output IC (Integrated Circuit or "chip"). It's the only source of power to the speakers and should be turned completely off when the radio is turned off.

With the onset of cold weather upon us, do not delay this repair. While it's relatively rare, malfunctions of this nature have been known to drain batteries while the car sits idle. Let us know what happens.

dh

Certainly the easiest way to check if the noise is coming from the speakers is to pull the fuse for the radio.

Is the sound level the same no matter what the volume is when the radio is on, or does it vary? Is it louder/quieter with different sources (radio, tape, CD)?

Speaker noise

You guys sound like you really know car stereos, so maybe you can advise. I have a 2006.5 Jetta TDI automatic, 16K miles. Since first week I've had an intermittent crackling sound mixed with squeaks and squeals coming from the right rear door speaker. This lasts anywhere from 3 seconds to 30 minutes. Sound volume remains the same with stereo in AM/FM/CD/SAT and even continues when in MUTE; stops when stereo powered OFF. There doesn't seem to be any relation to accelerating, braking, proximity to power lines, etc. Have been to dealer three times with issue. They've replaced that speaker and most recently replaced the entire radio, but the problem persists. Any ideas?

diesel4life said:

This noise is driving me crazy!!! I have a 2000 Golf TDI with 235k and i figure it must be the speakers that have this high pitched noise coming from them.

Even when the radio is playing all you can hear is the high pitch in the background. Even when I turn the radio off the sound is still there.

I'm pretty sure it has to do with a bad ground or something but where do I start. Or do I replace the whole deck? Will that solve the problem?

Does anyone else Have this?

The car has a Factory tape deck with a factory installed panasonic 6 disk changer in the back.

And I allready did a search on old topics and came out with no useful info.

Thanks

Click to expand...

I have the exact same issue on my 2000 Golf. I have replaced the headunit and there is no difference. I do notice that the pitch/loudness changes with the throttle.

luminous said:

You guys sound like you really know car stereos, so maybe you can advise. I have a 2006.5 Jetta TDI automatic, 16K miles. Since first week I've had an intermittent crackling sound mixed with squeaks and squeals coming from the right rear door speaker. This lasts anywhere from 3 seconds to 30 minutes. Sound volume remains the same with stereo in AM/FM/CD/SAT and even continues when in MUTE; stops when stereo powered OFF. There doesn't seem to be any relation to accelerating, braking, proximity to power lines, etc. Have been to dealer three times with issue. They've replaced that speaker and most recently replaced the entire radio, but the problem persists. Any ideas?

Click to expand...

Does your car have an audio ampifier external to the radio head? If there's no possible fix there, you may want to reassess the noise--is it possible this is some sort of trim buzz? There could also be a problem in a wiring harness somewhere, which is probably the worst of all possible causes of an issue like this--a major ***** to track down. Good luck.

dh

PharoahTDI said:

I have the exact same issue on my 2000 Golf. I have replaced the headunit and there is no difference. I do notice that the pitch/loudness changes with the throttle.

Click to expand...

Unlike the OP, I'm guessing your problem goes away when the radio is off? If not, do you have an external audio amp? What you describe sounds like alternator whine to me. That could indicate a bad ground or some other harness-related issue where stray RF from the alternator is finding it's way into the audio system. In the case of such a harness problem, probably the easiest fix for the noise is to put biggish inductors in series with each side of the power supply lines to the radio and amp (if there is one). That SHOULD cure the noise, but bear in mind other systems may be getting interference too which can cause erratic behaviors and you have not addressed the root cause--which may or may not become a bigger problem at some point. Allow me to give a couple of non-TDI examples:

There is a problem on a current model-year GM vehicle in which data communications from the audio system are throwing out JUST enough stray RF to cause false tire-pressure monitor alerts. Only a very small number of vehicles are affected, but a TSB has been issued in which the ground for the tire-pressure sensor is moved a few inches away from the radio ground point it currently shares. This has cured every instance so far. Here's the best part--GM engineering knew about the risk from past experience, but some knucklehead decided they could save a penny or two per vehicle by eliminating one screw and the labor to insert it. Every carmaker I've ever worked with (with the possible exception of Lexus) does crap like this all the time. Fortunately, in this case, the harness problem results in a mere annoyance.

Here's a more severe example. Many years ago I owned two consecutive Chrysler Horizon TC3's. Not bad little cars, but they nickle-and-dimed you to death as they got up in age. (Thankfully, Chrysler quality has made major strides in the last 10 or 15 years). These old Horizons had a braided wire strap for the alternator's ground. Corrosion eventually would cause this strap to lose conductivity and force the car's charging system to seek ground through some other path. In this case, the path of least resistance turned out to be through the right front wheel bearing. Over several hundred miles, the arcing across the bearing would trash it to the point that the wheel would wobble as you drove. On the way there, there was electrical noise a-plenty being made. I went through a couple bearings before we figured out what was going on. It seems unlikely to me that this kind of thing is happening in your TDI, but who knows?

I wish I could say just what was happening, but my experience with VW-specific systems is nil, and even if it wasn't it's almost impossible to say what's going on without actually inspecting your vehicle and trying a number of things to narrow the trouble down. Such is the nature of electronic systems.

If you (or anybody else here) are interested in the inductor fix I described, PM me. I have dozens of suitable parts in my junk box and will be happy to send you some for the actual cost of shipping--about $3.00. Hope that helps more than confuses.

dh

luminous said:

You guys sound like you really know car stereos, so maybe you can advise. I have a 2006.5 Jetta TDI automatic, 16K miles. Since first week I've had an intermittent crackling sound mixed with squeaks and squeals coming from the right rear door speaker. This lasts anywhere from 3 seconds to 30 minutes. Sound volume remains the same with stereo in AM/FM/CD/SAT and even continues when in MUTE; stops when stereo powered OFF. There doesn't seem to be any relation to accelerating, braking, proximity to power lines, etc. Have been to dealer three times with issue. They've replaced that speaker and most recently replaced the entire radio, but the problem persists. Any ideas?

Click to expand...

Do you use a Cingular cellphone?

http://www.audiojunkies.com/blog/127/what-the-hell-is-that-noise-coming-from-my-speakers

WB9K, its the stock radio with internal amp. The noise is there if the radio is on or off. It almost sounds like an alternator whine but not what I am used to hearing.

OP, are you sure you don't have the VW factory external amp in the trunk next to (actually under) the CD changer? Commonly referred to as the "monsoon" sound system?

If your factory radio has a "mid" button along with the bass and treble buttons, you probably have the Monsoon with the external amp. I bet the amp is the source of the noise - bad ground or faulty wiring somewhere along the line.

It may not be the most ethical approach, but one way to resolve the problem would be to have a shop install a new deck. If the noise goes away, great. If not, you can blame them for the problem and make them fix it.

jokila said:

Do you use a Cingular cellphone?

http://www.audiojunkies.com/blog/127/what-the-hell-is-that-noise-coming-from-my-speakers

Click to expand...

A couple of things on this. First of all, good catch, this is a real issue. Chrysler, among others has had problems in recent years with some vehicle models picking up noise from GSM phones (my first job in electronics was at Motorola working on GSM and CDMA cell phones, so I have some professional RF background as well). This could be Luminous' problem, but not the other guys who say it's happening with the radio off.

In the cases I am familiar with, this only happens when the audio system is on. Usually what happens is the RF interference gets coupled into the audio electronics AHEAD OF the power amplifier (where many systems are NOT balanced) and then gets amplified just like any other desired signal would. There are still a handful of OEM car audio systems made today that have single-ended outputs (meaning not-balanced) from the radio head--some of the low-level systems for Toyota and many in Hyundai cars are among them. However, the vast majority that I am aware of use power amplifier IC's with balanced outputs--the type of noise-immune system touted in the linked article. In a system with balanced outputs, inducing audible noise through an unpowered speaker (radio off) with a cell phone should be virtually impossible. In a single-ended system it would be theoretically possible I suppose, but audibility seems extremely unlikely.

Here's a (relatively) simple test to figure out if your car's system has balanced or unbalanced (single-ended) outputs to the speakers:

1)Get access to the back of one of your car's woofers. The tweeters probably have capacitors wired in series which can give misleading results in this test.

2) Measure the resistance between each speaker input terminal and the car's chassis ground with an Ohm meter. (Edit--The amplifier's wires to the speaker must remain connected to the speaker during this measurement.)

3) If the resistance on both terminals is high (typical 40 kOhms or more), the system is balanced. If the resistance on one side is zero, and near zero on the other side (typically 2-8 Ohms or so), the system uses single-ended connections.

TADC, do you (or anyone else here) have access to system schematics for any of the VW audio systems? I could give much more authoritative advice if I had some to look at.

dh

PharoahTDI said:

WB9K, its the stock radio with internal amp. The noise is there if the radio is on or off. It almost sounds like an alternator whine but not what I am used to hearing.

Click to expand...

I suppose it could be electrical noise from some other engine system like the IP which would also rise in pitch with rpm's. If you're SURE you don't have an external amp, I would give the inductor fix a try. If that works, then you'll at least know that there is excess electrical noise making its way into your radio. What you won't know is if the root problem has any more serious consequences than noise in your audio system. Hopefully somebody with actual experience fixing this kind of thing in TDIs will chime in.

(Edit--After thinking about this a while more, I realized it's possible that if the inductors fix the noise, it's still possible that the problem is in fact inside the radio in the form of a filter component--probably a capacitor--gone bad. Honestly, I would just try it and if it fixes the noise I'd go on my merry way. The chances of a major failure on the horizon are low, and even if there is one coming, trying to find it at this point is probably futile. Have the car scanned for DTCs with VAG-com. If all is clear, don't sweat it.)


dh