Can anyone tell me what this start noise is

[Gman1978]

Hi characters,

My Fabia 1 has been doing this noise on and off on startup, anyone know what it is? 
I’m wondering: alternator.. water pump?

any advice? Like do I need to get this sorted asap to protect the engine?

Thank you

 

Edited 21 January, 2023 by Gman1978

[VanhireBoys]

Well im no expert but the brother in laws Mk IV Golf TDi made that noise for years 😉

 

It sounds like the starter motor pinion gear is dry and causing friction on the shaft as it disengages. This should spin freely as the solenoid withdraws.

 

To fix it the starter will have to come out and either take it to get refurbished or as a temporary measure load it with spray grease !!

 

As I said I could be totally wrong but you can either rule it in or rule it out 👍

[Titanium_Man]

Yup, sounds starter to me too.  

[Warrior193]

^^^^^ agree with above. It sounds as if the starter pre-engage pinion is not being pulled away from the flywheel ring gear fast enough. Cure could be as simple as clean and lubricate pinion gear and shaft, but starter motor will need to be removed to do it. 

[Gman1978]

Thanks people!

I agree it sounds just like:-

 

note: a few months ago I did actually remove and attempt to re-grease the starter thinking it was that, but it didn’t make any difference. I can’t have done a good enough job.

I’ll do it again but with a rebuilt one from eBay (too much work to mess about), went for:

https://www.ebay.co.uk/itm/323768658186?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=wESXVx7VRnS&sssrc=2349624&ssuid=j1LvZPJGTWm&var=&widget_ver=artemis&media=COPY

 

i will report back.

Thank you all!

 

 

 

[Warrior193]

Good morning Gman, what did you 'grease' the starter pinion gear with? A good clean up, then apply a dry lubricant - or possibly Copper Ease  to the starter motor shaft would be what I would recommend.  

[J.R.]

Do not grease the pinion, if there is any stiffness it will be in the solenoid or actuating arme anyway but it is a complete red herring.

 

2 hours ago, Warrior193 said:

It sounds as if the starter pre-engage pinion is not being pulled away from the flywheel ring gear fast enough.

 

The pinion can disengage as slow as it likes, people with slow reflexes or hearing loss may not even release the key for a few seconds, as soon as the engine fires the pinion freewheels on the internal one way sprag clutch (roller ramp clutch) and when they start to fail they make the exact noise in the video, the same noise that an alternator pulley makes when the same one way clutch (fitted for a different reason) goes bad.

 

On a large capacity  motorcycle engine the starter pinion is in constant mesh with the ring gear, the ring gear carrier drives the crankshaft through a one way clutch, this will be spinning freewheeling at 11500 rpm without a murmer but if it fails then the starter motor will hit 100K rpm and vaporise, or as I found to my cost if you fit the bike engine and transmission unit into a race car and go into a spin unless you have lighning reflexes to declutch you will end up with a pile of smoking shrapnel under the bonnet.

 

If you can source the part the sprag clutches are easy to replace and repair an otherwise functional starter motor for very little money.

[Breezy_Pete]

Try removing and cleaning up the main electrical connections.

[SuperbTWM]

I would remove and manually pull out the pinion and spray a little silicone grease on the shaft after making sure it looks clean, last one I did needed only this, was just too much friction between the shaft and the seal due to dirt.

[sepulchrave]

Just replace the solenoid and all will be well, I need to do this as well but the starter is so inaccessible that I'll probably just pay the garage to replace the entire motor because I can't get it high enough in the air. Mine has been like it for six years so it's not urgent.

[J.R.]

The noise is the sprag clutch, the solenoid can be as lazy as you like or you can deliberately keep the key turned and the starter should not make any noise whatsoever aside from the almost silent motor whirring without any load on it.

 

Ignore it for too long and eventually it will lose drive when cranking, make an awfull screech and the engine will not turn, don't ask me how I know so much on the subject 😳

 

It has only happened to me once and I have not seen another one fail but there is no mistaking the noise the OP's starter is making. Most people do not realise that the sprag clutch is there, it's not visible and they hardly ever go wrong but if you think about how a pre-engaged starter works then you realise there has to be one to protect the starter motor from grenading, on an old school inertia bedix starter the acceleration as the engine fired would throw the pinion out of mesh and you would simply hear the motor whirring, the same noise that you would hear if a solenoid was lazy, not that screeching, it is unmistakeable.

[J.R.]

Likewise on an old school starter the acceleration of the starter motor shaft and the inertia of the bendix assembly will pull the pinion along the helix and into mesh with the ring gear.

[Gman1978]

Update, finally with the slightly warmer weather I have put in the new starter motor I bought a while back. Noise now gone, thank goodness.

Thanks all.

G