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I traded my e90 sedan for a 2005 e46 330ci coupe.

And the AM radio sucks.

What could be the reason?

Is there any way to fix this?

My car was CPO and came with tinted windows, I think they are factory tinted because the tint has BMW logo on it.

Could it be a metallic product in the tint film that is causing the AM radio signal to be so bad?
 

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Possibly. Also possibly a loose, undone, or cut antenna connection. The antenna is built into the rear glass and attaches on the sides. I remember when I had my rear window out, my radio reception sucked.
 

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Other cars have this problem a lot, too. It could be that the resistors in the wires or something is bad, or something to that effect. I'm not positive about the terminology, but basically your engine running is interfering with the radio. Do you get decent reception at stop lights, but then when you hit the gas the radio goes all staticky and crackly? That's how it is in my car and I never cared to fix it.
 

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Isn't AM reception just bad period. any radio or car ?
 

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i cant get any am signal in my car. I figured the old owner put the stock radio back in & didnt hook up the antenna right. not worth my time taking it out & looking just for am radio. any connections I might check?
 

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My AM reception gets terrible as soon as I leave the city otherwise it's perfect hence I think it has something to do with the antenna itself. AM = amplitude modulation i.e. the amplitude of a data signal (e.g. voice of a news caster talking) is modulated using a sinusoidal multiplier. Since the amplitude of the multiplier is modulated noise from other sources can affect it very easily e.g. reflections from buildings etc. Most AM radios car radios can either be great receptors when receiving highly attenuated (tiny) signals or they can be great in filtering out unwanted noise, but almost never both. I think our BMW's are great in the latter department. When you drive under power lines you shouldn't notice any problems in our bimmers. Try the same with a Honda and you'll notice so much noise you won't be able to hear anything else. However, take the Honda about 80 miles out of the city from a good AM station and you'll still get decent reception; in the bimmer you'll hear a bunch of noise.
 

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It is an Antenna issue.

AM Reception issues down to two basic ideas:
1. A good AM Antenna is most important: an inexpensive radio with a good antenna will outperform an expensive radio with a poor antenna.
2. A good antenna where there's no signal won't make a difference: the antenna has to be in the path of the radio signal.

Starting with these two simple principles, you can go a long way toward improving your AM reception without having to spend a lot of money or time.

First truth of AM reception is a good antenna. Outside of a few select radios engineered with AM radio listeners in mind, most radios treat AM radio like an afterthought. Many radio manufacturers have relegated AM radio to the past, to the days before FM, and they aren't fully aware of AM's continued popularity across the country. The consequence of this move away from AM is that many radios just don't have very good AM antennas. That means it's up to you to find a suitable AM antenna. More on this in a moment, first let's look at basic idea number 2.

If you're trying to listen to a radio station that doesn't broadcast in your direction, chances are very slim that you'll have much luck. Also, if your antenna isn't directed correctly at the signal coming your way, you'll also experience diminished reception. Ideally, your antenna should be at right angles to the AM signals coming toward it. Think of it in terms of trying to hit a baseball with a bat. Even if you are a phenomenal hitter, it is difficult to hit a pitch with the narrow tip of the bat. Sure you might come close, or if your lucky, you might even make contact with the ball, but you'll never make a good solid connection needed to hit a home-run or even get a base hit. The same is true with radio signals that aren't hitting your antenna

Choosing right AM Antenna requires that you get to know a bit about your specific needs. Steel and aluminum almost always cause AM reception problems unless of course you have a lot of windows (which by the way do not usually block AM radio waves. Best test for source of your poor AM reception problem is to take a portable (battery operated) AM radio in your car and move it around. If your reception improves, you've found your problem.

Open any radio with an AM section and you are sure to find a grayish black rectangular or round bar of metal, with wire wond around it on one end. This is the AM antenna. If you are not satisfied with your AM reception, you are probably wondering "is there anything I can do to improve it?" Well, yes you can.

Ferrite Bar; Your solution might be as easy as installing a larger ferrite rod. Ferrite is the grayish-black metal portion of the antenna. You have several things working for you:
***8226; Usually, the ferrite rod is secured by wax or some other to soft material to its mountings and to the coil. It should be fairly easy to loosen it and slide it out. Be careful not to break any of the wires on the coil, however! If you do you are in for a hard time finding a replacement. Sometimes the coil is not wound on a cardboard form, and is wound directly on the rod. If so, you are out of luck.
***8226; Cost usually dictates that they use as small a ferrite rod or bar as possible. There is usually plenty of room for a larger one inside the case. If not, or if there are components that interfere, don't try to replace it. Consider adding a signal amplifier.

***8226; If you are like me, you usually save parts from scrapped radios. I have a couple of dozen ferrite bars and rods. They come in standard diameters an areas, so it is usually easy to find one that will slide into the coil. Don't be afraid to make a rectangular coil round or vice versa. It will work just fine. A good rule of thumb for ferrite - the longer the better. Also, the larger the cross section, the better. But you don't have control over that.

Fortunately, the size of the ferrite rod does not have a lot to do with the tuning of the radio. Even if you have to compromise on a station near the center of the band, there will still be very worthwhile overall improvement. Especially if you are only after that one station!

To re-tune the radio:
1. Pick weak station near the low end of the band. Slide the ferrite through the coil and find the position that gives the clearest reception.
2. Trace the connections on the coil and find the one that goes to the tuning capacitor (or varactor antenna tuning stage).
3. Tune to a weak station on the high end of the band.
4. If there is a trimming capacitor (there usually is), adjust it for best reception.
5. Go back and forth a couple of times, re-adjusting the low and high parts of the dial - particularly if you made a big change in ferrite size.
6. DO NOT touch the ferrite on the high part of the band, or the trimming capacitor on the low part of the band!
7. When you are satisfied you have the best adjustment, use wax or rubber cement to secure the coil to the ferrite, and the ferrite to its mounting.

Richard
 

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The AM antenna on our bimmers is not a ferrite bar type, you can't change it out for a bigger one.

The signal comes in over the same antenna connection that the FM comes in on. Which means that the signal is received by the antenna lines on the rear windshield (on non convertibles). From there into the FZV antenna amplifier located on the left C*****ar (or in the upper part of the tail gate on wagons) and then to the back of the radio. The antenna lines on the rear window must receive three RF bands. 520-1700 kHz (AM radio), 87-107 MHz (FM radio) and 314 MHz (key fob transmit frequency). The design of the antenna for these three bands are different and the AM band gets the least amount of attention due to the difficulty. A quarter wave antenna for the key fob it's about .23 meters (.7 feet), piece of cake. For FM radio is about .75 meters (2-1/4 feet), no problem. For AM radio it's 44 meters or 132 feet and that's at 1700 kHz, BIG problem and it gets longer as the frequency goes down.

The AM reception should not be as bad you are describing however. The tint shouldn't make any difference. Try getting to the FZV module and removing all the connections, look for corrosion and then reconnect. Also check the connection from the rear window antenna to the FZV. It can come loose if someone was working back there and knocked it.
 

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When you drive under power lines you shouldn't notice any problems in our bimmers.
I notice just the opposite in my 2002 330i. Whenever I drive on a street with power lines overhead, I get increased static and whistling. When I go through an area without any overhead lines, my reception becomes cleaner, but still weak overall.
 

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factory tint? hmm. i've never heard of that. if the tint contains any metallic properties, it will affect radio reception.
 

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Your windows are stamped with the BMW logo anyway, but I doubt your tint is messing with the reception. If you're getting interference from everything, it sounds like a resistor coil or whatever we have in our radios is bad. When you're driving under power lines, during heavy acceleration, etc. It's typically isolated to AM radio.
 

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old thread, i know, but just thought i'd comment, as i had the same problem- i like kcbs in bay area and knx in la for traffic updates, and the whining and static and weak coverage area was driving me nuts. despite the drawn out and i'm sure accurate technical explanations here, i pulled off my c-pillar cover, disconnected everything, sprayed come electrical contact cleaner, reconnected everything, and presto! good reception, or at least better, and no more whine/feedback/static!
 
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