Technical Help please! Got my new 500 N running but sounds horrible.... sort of!

[ChiapC]

Hi all! Just getting started on this forum, but I’ve found some great stuff so far. To start off, here’s a video of my 500 running.

[ame]https://youtu.be/NSaZCOl8fo4[/ame]

Right when the car starts, this noise happens for a few seconds. The. It goes away. Then if the car bogs down at all as it does in this video, the sound comes back.

I tried to put it in gear and drive it as it was idling and revving fine, but as soon as you start to let the clutch out, the noise is back, big time.

I just pulled the engine, thinking it was a clutch/flywheel issue. But it all looks good. Even the pilot bushing isn’t well worn. There is Minimal play on the input shaft, on the trans, not sure if my trans is toast or not.

I put this vid up on Facebook and people thought my fan was loose. I confirmed the fan wasn’t the issue. Started it with the drive belt removed and the sound co tuned.

Thank you all in advance! I look forward to being a part of this forum!

 

[the hobbler]

Daft as this may be, it sounds as if the starter bendix is catching on the flywheel ring-gear. Check that the starter operating cable is not too tight and causing the starter to be 'nearly engaged' at times.

 

[The Whitakers]

Daft as this may be, it sounds as if the starter bendix is catching on the flywheel ring-gear. Check that the starter operating cable is not too tight and causing the starter to be 'nearly engaged' at times.

Superb!.....I've listened to the video several times this morning and recognised the sound but couldn't put my finger on what it was...….

 

[fiat500]

Daft as this may be, it sounds as if the starter bendix is catching on the flywheel ring-gear. Check that the starter operating cable is not too tight and causing the starter to be 'nearly engaged' at times.

Spot-on...you can see it on the flywheel teeth...

 

[Bigvtwin996]

Hi all! .................

I just pulled the engine, thinking it was a clutch/flywheel issue. But it all looks good. Even the pilot bushing isn’t well worn. There is Minimal play on the input shaft, on the trans, not sure if my trans is toast or not.
............

Thank you all in advance! I look forward to being a part of this forum!

my opinion as an Early car owner is "the car is toast"...
These early cars are too hard to find parts for and really not worth the trouble and expense...you should simply sell it and cut your losses....put it on a boat and I'll give you $1500

you won't find any of the fuddy duddies on here within a mile of a car like that.... especially with those funny headlights.... and big bumpers...

 

[ChiapC]

Daft as this may be, it sounds as if the starter bendix is catching on the flywheel ring-gear. Check that the starter operating cable is not too tight and causing the starter to be 'nearly engaged' at times.

I agree that it’s what it sounds like, but the only reason it runs is I jus had the starter rebuild with a new bendix and all other necessary parts. The old bendix was toast. The new one doesn’t have any marks on it that would show it’s hitting at all longer than it should.

Also, i don’t know why activating the clutch in gear would effect the starter bendix. I’m extremely confused by all of this still. Going to do all maintenance issues while the engine is out, re-seal the engine and hope something small was the problem, though it doesn’t sound like it.

It almost sounds like there is zero transmission fluid in it.... but again, not sure why it would be intermittent. I’ll keep you updated.

 

[ChiapC]

Here are a few pics of starter and flywheel. I suppose I could file off the small edges on the flywheel, but I really don’t think that’s the issue.

 

[ChiapC]

I hit submit before I could add these next two....

 

[fiat500]

Did you try tightening the impeller despite it being not apparently loose? When mine was faulty it only showed up as I started to speed up the engine. On tickover and at speed there was no problem. I had correctly torqued the nut; it wasn't loose but another half turn or so permanently cured the problem; I had even bought a new impeller.

 

[ChiapC]

But the sound even continues when the belt is disconnected and the fan isn’t spinning.... so I’m pretty sure the fan isn’t the issue. Lying underneath with the inspection plate under the flywheel removed, the sound seemed to be coming from the flywheel area.

I did remove the pilot bushing, which did have some play on the input shaft. Maybe a mm or so. I’ll be getting a new one soon.

Side note.... if any of you have heard about using bread to remove the old pilot bushing.... it works, surprisingly well too!

 

[fiat500]

Side note.... if any of you have heard about using bread to remove the old pilot bushing.... it works, surprisingly well too!

..heard of that, but brute force and welding was the only thing that worked for me. :bang:

Regarding the noise, it may be sorted now if something (eg. a stray nut or bolt) has been catching on the flywheel or clutch; did anything drop out of that cover-plate?

 

[ChiapC]

..heard of that, but brute force and welding was the only thing that worked for me. :bang:

Regarding the noise, it may be sorted now if something (eg. a stray nut or bolt) has been catching on the flywheel or clutch; did anything drop out of that cover-plate?

I was hesitant to try the bread, but figured it couldn’t really hurt.

Nothing fell out when I removed the cover. But hoping new stuff fixes any problems that may have existed....

There was what seemed like WAY too much oil in the crank case. Seemed like 3.5 liters or so.

I’ll be fitting new oil pan gasket, rear main, front seal, timing chain and sprockets, clutch, pressure plate, throw out bushing and likely a few other things! Fingers crossed

 

[Bigvtwin996]

Joking aside...
remember this is an N...
(I presume the engine number is 110.xxxxxx)
Whilst they look the same as later cars very little is really the same...
As you are in the USA parts may be more scarce than even Europe, so later parts may have been modified or such to fit... so something may have come loose that was adapted to fit or such...

 

[the hobbler]

This may sound like a silly suggestion, but it IS meant to be serious. (a) check your starter for any forward/back movement of the main shaft. (b) when you have the sump off, check that the crankshaft end float is correct and not excessive--it should be between 0.30mm and 0.44mm. This is measured with the crankshaft pulley in place and the big end-of-crankshaft nut done up to the correct torque (108.5 ft lb or, 15,000kgmm). The end float is measured with a feeler gauge between the crankshaft shoulder and (according to the FACTORY workshop manual) the flywheel-end bearing, although the picture in the manual shows the feeler gauge inserted between the crankshaft shoulder and the TIMING-GEAR end?! When everything is back together and you are ready to start the engine, leave the starter-actuation cable OFF and operate the starter with a length of timber or, if you can reach round the engine, your fingers. This will allow the starter to be in the 'fully away from the flywheel' position. The starter actuation cable can be adjusted to a small degree--the section that goes on the starter lever normally has 3 holes in it to allow you to effectively lengthen or shorten the cable. Please keep us in the picture as to the outcome of this problem---that way, we all learn

 

[ChiapC]

Joking aside...
remember this is an N...
(I presume the engine number is 110.xxxxxx)
Whilst they look the same as later cars very little is really the same...
As you are in the USA parts may be more scarce than even Europe, so later parts may have been modified or such to fit... so something may have come loose that was adapted to fit or such...

I do order most of my parts from FDRicambi as they have the best selection and shipping is crazy fast (though expensive). I’m trying to do this all right! It doesn’t seem like much was messed with in this car as all of the equipment looks original! Most of the bolts have FIAT on top of them. The throw out bearing was even original somehow. And was super gummy! Good thing I have a new one coming!!

 

[ChiapC]

This may sound like a silly suggestion, but it IS meant to be serious. (a) check your starter for any forward/back movement of the main shaft. (b) when you have the sump off, check that the crankshaft end float is correct and not excessive--it should be between 0.30mm and 0.44mm. This is measured with the crankshaft pulley in place and the big end-of-crankshaft nut done up to the correct torque (108.5 ft lb or, 15,000kgmm). The end float is measured with a feeler gauge between the crankshaft shoulder and (according to the FACTORY workshop manual) the flywheel-end bearing, although the picture in the manual shows the feeler gauge inserted between the crankshaft shoulder and the TIMING-GEAR end?! When everything is back together and you are ready to start the engine, leave the starter-actuation cable OFF and operate the starter with a length of timber or, if you can reach round the engine, your fingers. This will allow the starter to be in the 'fully away from the flywheel' position. The starter actuation cable can be adjusted to a small degree--the section that goes on the starter lever normally has 3 holes in it to allow you to effectively lengthen or shorten the cable. Please keep us in the picture as to the outcome of this problem---that way, we all learn

I’ll give both of those a shot. I do know the starter cable was a bit tight, but nowhere near activating the switch. I could loosen it as there are the other holes to put the cotter pin through.

I’ll also try the feeler gauge with the crank.... should be easiest once I pull the rear main.

Thank you all for your help so far!!

 

[ChiapC]

So after looking it at it again.... I think you’re right on about the starter bendix. I didn’t realize the arm pushes the bendix up with any movement and that it’s not an electrical pulse that shoots it forward and spins it!

Once I clean it all up and put it back in, I think that’ll do it!

 

[Toshi 975]

I do not know about the N models but on most 500 & 126 there is a thin metal cover plate under the starter motor. If that was missing it would give the flywheel slightly less clearance on the bendix. I have also come across starter actuating/solenoid arm return springs not locating properly And not working. Sure fire way to pin it on the starter is to remove it and bump start the car.

 

[the hobbler]

It is amazing what one thinks of lying in bed on Christmas day morning whilst 'er indoors is rattling on about "what shall we have for breakfast dear?". I suddenly remembered that i have been having the REVERSE problem with the engine in my 500. I have a 652 '126'engine in it with a 500 flywheel fitted (it is 2kg lighter than the 126 flywheel). Either flywheel will fit on any of the 110/126 variants, BUT the 500 flywheel is more inset where it bolts on to the end of the crankshaft, so effectively the ring gear is slightly further AWAY from the starter and occasionally the starter 'misses' when operated and just spins. If a 126 flywheel has been incorrectly fitted. the ring gear will be CLOSER to the starter, which will cause the ring gear and starter bendix to interfere.
The observation by Toshi is sound regarding the little cover plate--I will look in my 'parts book' (Fiat works version). His suggestion re 'bump starting' is also sensible.

 

[the hobbler]

I have looked in both my parts book and my 1963 workshop manual which covers the 500N. Neither of these factory publications show,or mention, a starter/crankcase shield as is fitted to the 126 engines. But looking at the 500N information, 1 thing did spring (?!) to mind. Built onto the pivot pin for the starter operating lever (that pulls the bendix onto the starter ring) is a fairly strong spring which returns the bendix away from the starter ring---how strong is that spring on your starter?Is it a bit weak and knackered? If it was, it would not pull the bendix back away from the starter-ring. As 'Toshi' suggested, try a 'bump' start with the starter left off. But don;t forget to connect the feed wires that go to starter together (with a bolt through them) AND INSULATE THEM.