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Freakish rotating sounds under hood (No key in ignition)

I tried starting my car after about 5 days of non-use. Turning the key started an unusual rotating sound under the hood (It was not a fan or the door locks or other electrical device running unhindered.) This rotating sound did not stop after key was removed from the ignition. Subsequent attempts to turn the key and start the car neither started the car, nor stopped the rotating sound. The key would turn normal, and normal dashboard lights came on and there were no clicking or engine starting sounds. However, the car wouldn’t start and the unstoppable rotating sound continued for about 10 min. at which point the creepy rotation built up speed quickly and then a brute clunk and silence. Followed by strange sort of sweet smells. Any insight??

There’s a problem with your car. Have you been able to open the hood? When you say “turning the key” do you mean to the on position or the start position?

Is this a Citroen, a Lamborghini, a Delorean? Someone is going to ask you for make, model, mileage, year, and maintenance history.

Clearly your starter isn’t working for some reason, since the car won’t start. The starter does rotate, on a good day, but it needs to engage the engine to turn it over.

I can’t say for sure the problem is the starter, but I am confident that the problem is under the hood.

Short answer: sounds like an interesting problem.

Well, I’m not entirely sure what a “creepy rotating sound” is, but you might be describing a freewheeling starter.

“Is this a Citroen, a Lamborghini, a Delorean?”

Well, judging from the tag underneath the post, I will venture that it is probably a VW “New Beetle”.
Of course, it would be nice to know this VW’s model year, odometer mileage, whether it is under warranty, and its maintenance history before we attempt to go any further.

Can the OP please fill in the blanks, as well as give a description that is clearer than “creepy rotating sound”?

Did it sound like a fast rotation or a slow rotation?

If the starter motor was running without turning the engine it might do what you describe. It would sound like an electric motor running, sort of a whirr.

If the rotation was slow I’m stumped.

Did you open the hood and look for clues as to where the sound might have come from?

VW New Beetle. Year unknown. Check the tags under the post.

Thanks for the help! It’s a 1996 Volkwagen Jetta. I’m new to the forum and thought it was added from the drop down boxes I selected. Turning the key to any position does nothing. I was more concerned what the rotating sound could be. it was under the hood more to the passenger side of the car. It sounded surprising very similar to the general hum of parts moving when my engine is running, but I could tell my engine was not running. It was not a starter sound, if that makes any sense. Frightening that something could be moving, or “running” when the car was off. The sound accelerated so quickly that I ran from the car fearful of some sort of event. The acceleration ended with a bang and surely something is terribly damaged.

Thanks for the post! It wasn’t a slow rotation sound… but only became alarmingly fast before it went out with a bang. Thanks for the info about the starter motor! The sound came more from the passenger side.

thanks! I will look this up.

After checking this out briefly, this seems like a good lead. Not knowing really how to distinguish what a starter motor would sound like throws me off a little though. The only “starter” sounds I am familiar with is the second and a half of sound following turning the key and it wasn’t anything like that sound. What I do know is that sound was rather loud - almost as loud as the normal engine running sounds, I could hear it faintly even when I was indoors… would a starter motor that wouldn’t disengage sound loud enough to hear indoors?

Noted with interest: not a Beetle.

IF it’s the starter (as I suggested) it’s not that it won’t disengage, it’s that it won’t engage. If it’s really loud, consider the possibility that it’s almost engaged, just enough so the teeth on the starter’s cog (right term?) are brushing the teeth on the motor’s.

I am probably being clumsy with the terminolgy as well as with other things. The sound is long gone, since whatever was turning ended with an abrupt clunk that sounded as if something broke. From what I can gather it seems plausible that the starter motor kept going due to a faulty relay and after 10min burnt out. Admittedly, I don’t know what a starter motor is or what it sounds like… but very thankful this discussion has given me some path forward and least parts to search rather than my inscrutable experience with sounds. Thanks for you contribution (did not realize I may have erroneously chosen beetle from the drop down meun :wink:

Normally, with VW’s, when you unlock them (and/or depending on year, turn the key to “ON” before you start, or when you open the door), the fuel pump will pressurize the system. This sound is kind of like a hair dryer, but not quite as loud - sort of like a buzz. And it tends to sound like it’s under the car, right where your butt would be, and not on the engine. Do you still hear that one? You may not hear it if you’ve touched the car in the last few hours. It takes a while for the system to de-pressurize.

When you turn the key, and continue past “ON” to “START”, do you hear the engine turning over, like it wants to start, but then just won’t?

The starter sounds like a good candidate, but there are more possibilities.