Technical Loud Screeching Noise when car starts

[calliebofilatos]

Hi everyone,

I have a 2014 Fiat 500 that has been making a really loud screeching noise when it starts for about a month now. It is just as I turn the key before the engine starts. It will only stop if I release the key. I sometimes have to do this a few times before the car will actually start up.

I have uploaded the video to YouTube so you can hear the noise: (I cannot post a URL) so please search for "Fiat 500 Screeching Noise on Startup" by Callie Bofilatos.

I have taken it to 3 garages now and have had the following diagnosis:
Battery - I have replaced and it still makes the noise
Starter - I have replaced and it still makes the noise
Ring Gear & Flywheel - I have had a look at it and it has some wear and tear but definitely not this!

Please help!

 

[PuntoHowTo]

This is the URL, you can only post links when you have posted a few time, this is to prevent someone joining the forum and spamming it with links

[ame]https://youtu.be/dwDZquReWMI[/ame]

Sounds like a faulty started motor to me, but there is only a fraction of a second of the noise on one attempt to start it and then the video ends.

 

[calliebofilatos]

Thanks for posting the video Andy!

Yip - it's for about 1 second at the 7 second mark. It's quite quick because I turn the key off immediately because of how loud it is. It will continue doing it until I turn the key off.

I wish it was the starter motor but I replaced that 2 weeks ago.

 

[typecastboy]

Certainly sounds like the starter is not engaging. Is it a diesel? If so, then if the car is fitted with a dual mass flywheel then I’m confident it’s the DMF.

 

[calliebofilatos]

Certainly sounds like the starter is not engaging. Is it a diesel? If so, then if the car is fitted with a dual mass flywheel then I’m confident it’s the DMF.

Unfortunately it's petrol... any advice now?

 

[John202020]

Why did you replace the original starter?
Sounds like poor engagement
Have you replaced the engine earth strap on the right of the engine? If you have a battery jumper cable, try from any good metal point on the car engine to the battery negative, try starting, does it make the same sound?

 

[PuntoHowTo]

If the ring gear has gone on the starter then the new starter will still make that noise.

 

[Pugglt Auld Jock]

Thanks for the video, so much easier than trying to guess from a written description. I've heard that noise many times on many different vehicles. the pinion is failing to properly engage with the ring gear on the flywheel. The noise is the starter pinion teeth "skipping" against the edge of the ring gear teeth. I am about 99% certain of this.

Now as to why it's doing it is not so easy. You say you've replaced the starter? but did you check that the new starter had the same pinion as the old one? (ie same number of teeth and did it look the same). You also say you've checked the ring gear but did you rotate the engine and check all round the ring gear? typically you'll find just two worn sections with nearly all the other teeth looking good. This is because the compression strokes will force the engine to always stop in one of two possible positions - for a 4 cylinder that is, different for a 6, V8, etc - so you need to check all round. If you find a bit with maybe even just 3 or 4 rounded off teeth this can cause it.

Next time you try starting it, if it makes the noise, stick it in top gear and "rock" the car to slightly rotate the engine - it doesn't need to be a lot - try to achieve maybe 90 degrees rotation of the crankshaft but it's not critical as long as the engine turns just a little bit. Of course you will need to be on level ground to do this safely. Now try the starter again. If the problem is down to ring gear wear, because the ring gear is now presenting relatively unworn teeth to the starter pinion the theory says it should engage and spin her up. Make sure you put her back into neutral before you twist the key though won't you!

Good luck and do let us know how you are getting on
Jock

 

[Ralf S.]

What Jock said.

And which garage said it was "the battery"... Seriously?



Ralf S.

 

[calliebofilatos]

Surprisingly an approved Fiat garage...

 

[calliebofilatos]

Thanks Jock,
I ended up replacing the ring gear and flywheel after reading your message and it seems to have solved the problem so no more screeching noise when I start my car - yay!

Thank you ALL for your help and input.

Thanks for the video, so much easier than trying to guess from a written description. I've heard that noise many times on many different vehicles. the pinion is failing to properly engage with the ring gear on the flywheel. The noise is the starter pinion teeth "skipping" against the edge of the ring gear teeth. I am about 99% certain of this.

Now as to why it's doing it is not so easy. You say you've replaced the starter? but did you check that the new starter had the same pinion as the old one? (ie same number of teeth and did it look the same). You also say you've checked the ring gear but did you rotate the engine and check all round the ring gear? typically you'll find just two worn sections with nearly all the other teeth looking good. This is because the compression strokes will force the engine to always stop in one of two possible positions - for a 4 cylinder that is, different for a 6, V8, etc - so you need to check all round. If you find a bit with maybe even just 3 or 4 rounded off teeth this can cause it.

Next time you try starting it, if it makes the noise, stick it in top gear and "rock" the car to slightly rotate the engine - it doesn't need to be a lot - try to achieve maybe 90 degrees rotation of the crankshaft but it's not critical as long as the engine turns just a little bit. Of course you will need to be on level ground to do this safely. Now try the starter again. If the problem is down to ring gear wear, because the ring gear is now presenting relatively unworn teeth to the starter pinion the theory says it should engage and spin her up. Make sure you put her back into neutral before you twist the key though won't you!

Good luck and do let us know how you are getting on
Jock

 

[Pugglt Auld Jock]

Thanks Jock,
I ended up replacing the ring gear and flywheel after reading your message and it seems to have solved the problem so no more screeching noise when I start my car - yay!

Thank you ALL for your help and input.

That's great news - I'm very pleased for you. As I previously said, I've heard that noise (or something very like it) so many times it was an easy call for me.

I've actually been feeling just a little p****d off due to Becky (our Panda) needing her "incontinent" front strut problem sorted out and subsequently snapping off one of the main strut pinch bolts! None of it's a big technical problem for me but is a nuisance and quite expensive to sort out properly. Hearing of your success has cheered me up a lot! Thanks.

Regards
Jock