Technical Engine sometime make strange noise on startup

[arizonaPunch]

Hello,

My 2011 1.2 Fiat 500 sometimes makes a strange high pitch noise when I start the engine. This only happens about 10% of the time and goes away after a few second or after turning the engine off and on again, the engine then run completely normal. Does anyone have any idea what could be causing it?

 

[steveras57]

Few things to consider!
Have a listen in the engine bay as the noise might be easier to locate outside the car!.
Have you checked the condition of the alternator drive belt? if its worn or old and dry might cause this!
Is the air -con turned on? if so turn it off so its not under load and see if anything changes?(compressor on the way out!)
It could be a bearing in the alternator or air con compressor on the way out! if so will get worse over time increasing in frequency and duration!
If you have access to a mechanics stethascope you could test these points with some one else starting the car( mind all the bits spinning around in there! safety first!) any point of failure should be fairly obvious!

 

[348azeus]

The most likely candidate is the auxiliary drive belt check its tensioner bearing at the same time .

 

[steveras57]

see points1& 2in my reply!

 

[The Panda Nut]

Thats not a belt. Its a bearing maybe an alternator starter or starter. Start by oiling the alternator bearings with spray oil and see if it quietens. Its the sort of noise that says fix me before driving to me. Could be cam belt related! It dos have oil in??

 

[steveras57]

see points 3&4 in my reply!

 

[The Panda Nut]

see points 3&4 in my reply!

The oracle has spoken everyone else please keep quiet?

 

[steveras57]

well done that put me in my place didnt it! thats what i get for letting my ego overide my common sense and enthusiasm to help other members!.

 

[John202020]

It's not the AC the noise is there immediately after start up, the AC waits about 5-10 seconds before engaging the compressor?
Don't wait for this to be investigated
When was the timing belt last replaced?
Have you checked the oil level?
Does sound like a bearing hence don't wait

 

[steveras57]

It's not the AC the noise is there immediately after start up, the AC waits about 5-10 seconds before engaging the compressor?
Don't wait for this to be investigated
When was the timing belt last replaced?
Have you checked the oil level?
Does sound like a bearing hence don't wait

sooner rather than later appears to be the consensus!

 

[jackwhoo]

Starter motor pinion not disengaging from flywheel correctly???
If you get the noise stop engine immediately and try again.

Get it sorted asap whatever it turns out to be.

 

[steveras57]

Starter motor pinion not disengaging from flywheel correctly???
If you get the noise stop engine immediately and try again.

Get it sorted asap whatever it turns out to be.

Good call Jack!

 

[John202020]

Don't think it's the starter, I've had that issue on ours as has others, it's a more shrill noise and only lasts about 1.5 seconds as the starter cog slows down after disengaging? Assuming it has disengaged?

 

[steveras57]

I think the previous suggestion to oil the alternator bearings is the first best action !- at least if it does not make any difference you will have probably have eliminated that as the problem( as long as the oil managed to penetrate the bearing as if its a sealed one it might not!). of course this raises the seriousness level considerably so then more urgent action will be required!

 

[arizonaPunch]

Thank you all for the replies,

• I checked the oil levels and they are fine
• Bit sceptical about it being a bearing, surley I would hear the noise all the time, where this only happens very infrequently?
• The starter motor pinion not disengaging propperly is a good shout, that would fit with the sound only happening on startup.

I will do some investigating, and probably get it booked into a garage. I'll post any updates if the cause is found.

 

[348azeus]

It’s relatively simple to check. Disconnect the aux belt and start the car. If the noise has gone it something to do with the aux belt or something it’s driving. If it hasn’t gone then it’s could be the cam belt area such as the tensioner. If a bearing is worn it’s unlikely that you would get any oil into the bearing just by spraying it as they sealed.

 

[steveras57]

It’s relatively simple to check. Disconnect the aux belt and start the car. If the noise has gone it something to do with the aux belt or something it’s driving. If it hasn’t gone then it’s could be the cam belt area such as the tensioner. If a bearing is worn it’s unlikely that you would get any oil into the bearing just by spraying it as they sealed.

Thats a good call to temp disconnect the belt!- i was not sure if it was a sealed bearing but makes sense that it would be! this should help the OP narrow down there problem!.

 

[cris1603]

Hi, arizonaPunch!
Did you manage to solve the noise problem? What was the issue?
I have the same thing right now with my 1.2 Fiat 500.
Thanks for your reply!

 

[The Panda Nut]

On the Panda / 500 the alternator is very low mounted and subject to soaking on flooded roads. We had a really bad problem but the noise was not quite as bad as this. I sprayed the alternator with everything. Really soaked each end as much as possible. It gradually stopped. It had spray PTFE penetrating oil, 3 in 1, WD40, Silicon lube and penetrating oil sprayed daily for weeks before it stopped. Trouble is, getting at the bearings. You need spray cans with tubes on the nozzles to be able to direct the jet. Engine needs to be running too for much penetration. My method was saturation. I have dealt with nasty alternator bearings on a few cars and thankfully no adverse affects from these products ever noted. Avoid the belt though. Generally the noise went away as the car was driven off. It was ok on some days but it did happen when driving at speed as well on rare occasions. If the alternator seizes and chews the belt up there is a risk it could rip the cam cover off and wreck the cam belt and engine so be careful to get it resolved asap. As others have said belt tensioners could also cause this so carefully oil the tensioner wheel too. Dry alternators sound more high piched than this in my relatively slim experience. Due to the difficulty of accessing the alternator if you remove it for checking / cleaning and lubrication its economically more sense to replace it. It could also be sand and grit in / on the bearings. If you remove the aux belt rotate the alternator backwards which may dislodge debris and vacuum where youcan reach.