Buzzing sound
- Thread starter Bry1234
- Start date
Wow, this is a way out in left field guess, and it's probably not what is going on with that vehicle. That said, sometimes the designers of vehicles have built into the system a way to make the spark plugs get much more power while starting and maybe for a little bit after that. So, I'm thinking that it might be drawing a lot more amperage for that brief amount of time. However, the fact that you're getting some kind of a buzzing noise might be that you also have poor contacts and they can't handle the extra current for that brief amount of time.
If you know anybody with a clamp on amp meter and can isolate the wires that are being energized from that switch it might be worth your while to take some readings and see if indeed there is at least one wire that has excess current going through it for that time that you're getting the buzzing. The excess current might be normal but that would indicate that maybe the contacts of the switch are worn out they can't handle it also because of their buzzing.
Again, this is still a way out in left field guess.
However, years ago, like many years ago I do remember that ther were vehicles that when I got into what was going on with them during start they had More Voltage going to the ignition coil and after start they ran the ignition coil at less voltage going into it. They actually had dropping resistors and during start the dropping resistor that was between the Plus of the battery and the power for the ignition coil was a much lower value allowing higher voltage and more current to be applied to the ignition coil power input circuit.
One of the reasons any engine manufacturer would want to do a hotter spark during start and for a brief time after is that during start you're running the engine really rich and you combine that with cold weather (cold air being drawn in and a cold engine) and you have a great recipe for getting the spark plugs so wet that they actually won't Spark because the fuel that has them so wet can actually short them out. So the recipe for preventing that from ever happening is to have the spark plugs running extremely hot for a very brief amount of time during starting, and maybe for a little bit more time until the fuel system has stabilized to a rich mixture that is not rich enough to wet a spark plug. Also, the temperature of the spark plug comes up pretty quick and after a half a minute or so it might be that the problem of having it get too wet becomes a lot less likely.
If you know anybody with a clamp on amp meter and can isolate the wires that are being energized from that switch it might be worth your while to take some readings and see if indeed there is at least one wire that has excess current going through it for that time that you're getting the buzzing. The excess current might be normal but that would indicate that maybe the contacts of the switch are worn out they can't handle it also because of their buzzing.
Again, this is still a way out in left field guess.
However, years ago, like many years ago I do remember that ther were vehicles that when I got into what was going on with them during start they had More Voltage going to the ignition coil and after start they ran the ignition coil at less voltage going into it. They actually had dropping resistors and during start the dropping resistor that was between the Plus of the battery and the power for the ignition coil was a much lower value allowing higher voltage and more current to be applied to the ignition coil power input circuit.
One of the reasons any engine manufacturer would want to do a hotter spark during start and for a brief time after is that during start you're running the engine really rich and you combine that with cold weather (cold air being drawn in and a cold engine) and you have a great recipe for getting the spark plugs so wet that they actually won't Spark because the fuel that has them so wet can actually short them out. So the recipe for preventing that from ever happening is to have the spark plugs running extremely hot for a very brief amount of time during starting, and maybe for a little bit more time until the fuel system has stabilized to a rich mixture that is not rich enough to wet a spark plug. Also, the temperature of the spark plug comes up pretty quick and after a half a minute or so it might be that the problem of having it get too wet becomes a lot less likely.
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The fact that the problem is occurring only when it's cold might be that the computer for the vehicle is smart enough to only run that extra high power for the spark plugs only when it's cold. And again this is only a guess that this is what's going on.
And the sound changing with RPM of the engine also points in the direction of what I was saying about it being tied into the ignition system during starting in cold weather.
Diagnosing something without it actually being in front of you and being able to take readings and mess with it to figure out what's going on it's pretty hard to do. But in this case, I think I'm going to have a sore arm from patting myself on the back if it turns out that I called this one right. LOL.
I remember ap 1992 a friend of mine had to take his wife someplace on the morning that it was minus 20° f. The engine in his brand new Cadillac would not start. Apparently, he had already gotten the spark plugs wet with fuel when he tried to start it that morning and it was cranking very slow with only the vehicle's battery trying to get it to start. We jump started it and got it turning fast but it would not fire. He pulled a spark plug and it was wet. He changed all eight spark plugs that morning when it was -20° F and the car was outside.
Sometimes an extra hot Spark that draws a lot more power for a brief time during starting in cold weather can be a really nice thing to have. And I wouldn't be surprised if that benefit was not incorporated into the design of that Cadillac back then.
Sometimes an extra hot Spark that draws a lot more power for a brief time during starting in cold weather can be a really nice thing to have. And I wouldn't be surprised if that benefit was not incorporated into the design of that Cadillac back then.
Check for a loose hymenoptera in your Ford.
I was thinking that since it was increasing or decreasing with rpm it must be tied to the alternator. Also on a separate issue I get a electric buzzing noise only when hvac on defrost setting through car speakers up and down with rpm, although I believe that’s from no Freon in the ac lines.
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Does your car have a passive anti-theft device built in? Several years ago, I remember seeing a ring shaped electronic device around the ignition on my Mazda which was designed to pick up the signal from the key. If it is coil like in design it can resonate and perhaps this is what you are hearing?
Can you just yank the positive charge cable and see what happens? Or remove the exciter current if so controlled?
You'll get a battery light, but so what.
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So if your alternator fails or belt breaks while driving you'll fry your ECM?
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No, but disturbing the power flow like disconnecting the + cable sure can. And technically an alternator can fail hard enough to kill one too.
Do not disconnect the + while a modern car is running. It can be done, and may not hurt anything, but it very well can, and it'll ruin your day when it does. Not if. When.
