Car won't start, makes buzzing sound when turning ignition

[andyg7]

Okay so first of all the current state of my car:

My car hasn't started in a week or two, when I turn the ignition it doesn't even turn over (the starter seems to do nothing) but I can hear a buzzing sound coming from the mid-rear of the vehicle, underneath. Video:

https://www.youtube.com/watch?v=6feIwIOwJNI

You can hear the buzzing sound when I stick the camera out the door. The sound system and all other electronics work just fine. I actually just bought a new battery which didn't fix the issue. I thought that maybe it was a bad connection between the battery terminals and the leads but if that were the case I don't think the electronics would be working as normal.

How it started/progressed over time:

It started about 4 months ago. At first, my starter wouldn't respond immediately when I turned the ignition. After holding the key for a few seconds it would start. The delay got longer and longer until it wouldn't start. When that happened a jump start would usually get it going. Or sometimes I would simply leave it for a day and then it would start the next time. And after every time I got a jump it would be fine for a few more days, then the starter would be delayed, then eventually it would crap out again. This problem became more and more frequent until recently when I just stopped bother trying to start it.


My guesses would be either the starter/solenoid or maybe an electrical issue. Anyone have any ideas? Thanks!

[Kershaw]

Starter solenoid sounds like a really good place to start diagnosing.

[ELVA164]

It's hard to tell on my phone but I think that noise is your fuel pump. Check the wires to the starter as well as the ground. If you hear a click when you turn the key, that suggests a bad solenoid. You have anyone who could push start you/do you know the procedure for a push start? If the car runs with a push start that would also suggest a starter issue.

[323i E30]

That buzzing sounds like the fuel pump indeed. I wouldn't worry about that.
If you're not even getting a 'click' from the starter, then it could also be your ignition switch.
Not sure how to make sure of that, but I had a similar issue 15 years ago with my first E30 which was fixed by replacing the ignition.

[andyg7]

The car runs fine when push-started. Am I correct in thinking that that rules out fuel pump?

[ELVA164]

Yeah, the fuel pump is fine. I'm leaning towards starter, either due to faulty wiring, a bad solenoid, or a bad starter.

[andyg7]

Is there any way of confirming what the problem is other than taking the starter apart? The fact that the buzzing is coming from the middle/back underneath the car (nowhere near the starter) leads me to believe it's an electrical connection.

[frostedE30]

Get a long extension and beat on the starter while you have someone turning the key(though don't beat on it too hard), and if it turns over you have a bad starter or solenoid.

[ELVA164]

That noise you hear is the fuel pump. It has nothing to do with your problem. I'd suggest checking all the wires going to the starter as well as the grounds in the engine bay.

[Tom D]

sounds like the fuel pump running to me, but why is it running? the ecu shouldn't be switching on the pump until it gets a signal from the crank sensor.

OP, start with cleaning your battery connections and charge.

[Kershaw]

It's running because he turned the key into on the ON position.

Two things I can think of:
1. manually ground the positive of the starter solenoid to ground, screwdriver, wire, be careful, etc.
2. manually ground the 2 wires on the ignition cylinder. http://www.e30tech.com/forum/showthread.php?t=32047 here's a diagram, hopefully the pics work. (blocked for me at work.)

Hopefully that will tell you which item is faulty.

edit: I used to start my e21 with a screwdriver, just touched the 2 wire contacts at the same time. Haha. Then I just wired in a momentary switch because the ignition cylinder was bad.

[ELVA164]

It's running because he turned the key into on the RUN position.

But yes, the fuel pump starts running when the key is turned to "run," then continues once the car is running obviously.

I'm curious to hear what you find out, OP.

[Tom D]

....It's (fuel pump) running because he turned the key into on the ON position....

I'm going to start off by stating that i don't own an E30 325i, but i do own an E30, have done a M20B25 and 2 M42 swaps and i don't think that you're correct, the fuel pump should not be running if the engine is not.

with my M42 powered E21's the motronic unit controls the fuel pump relay and it will only ground the fuel relay if it sees a signal from the CPS, this is a safety factor. otherwise the key could be turned on but lets say the car has crashed, pumping fuel into an accident scene would be a bad thing. since the M20 is also controlled by motronic and therefore the pump relay is also being handled by the ecu, i think you're probably wrong. the pump might activate momentarily when the key is switched on to pressurize the EFI, but no way should it be running continuously without a signal from the CPS.

[ELVA164]

I'm going to start off by stating that i don't own an E30 325i, but i do own an E30, have done a M20B25 and 2 M42 swaps and i don't think that you're correct, the fuel pump should not be running if the engine is not.

with my M42 powered E21's the motronic unit controls the fuel pump relay and it will only ground the fuel relay if it sees a signal from the CPS, this is a safety factor. otherwise the key could be turned on but lets say the car has crashed, pumping fuel into an accident scene would be a bad thing. since the M20 is also controlled by motronic and therefore the pump relay is also being handled by the ecu, i think you're probably wrong. the pump might activate momentarily when the key is switched on to pressurize the EFI, but no way should it be running continuously without a signal from the CPS.

See my post Tom, with the key rotated fully to the run position the fuel pump is energized. Once the car has started, the CPS takes over and the pump runs with the key in the on position.

For clarity, the key has 4 positions:
1) Remove key
2) Accessory
3) On
4) Run

I don't know if M42 cars are the same, but I'm pretty sure this is how M20 cars work.

[Bennysbmw]

Hook a hot wire up to the starter

[andyg7]

Hey all sorry about the lack of replies. Unfortunately I have very limited tools at the moment and nowhere to work on my car other than on the street. So I'll be giving her a push start tomorrow and heading to the shop. Never taken my car in for diagnostic work before, hopefully it won't cost me too much.

Thanks for all the great replies!

[323i E30]

Good luck!

[PostChris909]

Any luck here on your issue?

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