Technical 1.2 engine vibration shudder

[Danoid]

Hi,

When using electrics such as electric windows, turning heater controls on (non AC car), headlights etc the revs drop a bit, this is somewhat expected but there's a shudder/vibration feeling in the car which isn't normal.

Driving the car is absolutely fine and feels smooth, idling is smooth too just not when using electrics. However if I bring the revs up a bit then lower it shudders a little bit.

I'm on a Fiat 500 FB group and someone posted a video of their car doing the same, although mines not quite as bad.

https://youtu.be/z9UZbm1Hhss

Last year I changed the spark plugs as part of the routine maintenance and battery is only 2 years old, so it won't be them or very unlikely as I had the same issues before anyway (been a few years like this).

Is this looking more like an engine mount issues and more specificially the rear one?

 

[John202020]

Welcome, what age is the car?
If its over 5 years old, replace the engine to body earth strap, about £4 on Ebay
Whilst yours indicates an electrical loading, also check the breather hoses thick to air box top of engine and thin rear of engine to air box.
When replacing the plugs use Iridium not standard ones.

 

[Danoid]

Welcome, what age is the car?
If its over 5 years old, replace the engine to body earth strap, about £4 on Ebay
Whilst yours indicates an electrical loading, also check the breather hoses thick to air box top of engine and thin rear of engine to air box.
When replacing the plugs use Iridium not standard ones.

Doh I completely forgot to mention it's a 2009.

Not too long ago I also lubed up my clutch slave cylinder piston thing as it was creaking like mad, whilst there I did check the earth strap and looked in good condition, so don't think it's that.

I'll go and have a look at the breather hoses in a minute, see whats what, but doesn't a breather hose just do exactly that and wouldn't cause the vibrations? I thought a failed breather hose would just emit fumes

I understand the iridium plugs are better, but also not standard, seeing as they're only a year old is it really likely to be them?

 

[Danoid]

Just had a look at the breather pipes and they're fine, annoyingly when I just started the car I had the lights on and used electrics, saw the revs drop but not vibration.


I wonder if the there's something possibly going wrong with the alternator, cars only done 26K miles though so unlikely

 

[Baglady1990]

Doh I completely forgot to mention it's a 2009.

Not too long ago I also lubed up my clutch slave cylinder piston thing as it was creaking like mad, whilst there I did check the earth strap and looked in good condition, so don't think it's that.

I'll go and have a look at the breather hoses in a minute, see whats what, but doesn't a breather hose just do exactly that and wouldn't cause the vibrations? I thought a failed breather hose would just emit fumes

I understand the iridium plugs are better, but also not standard, seeing as they're only a year old is it really likely to be them?

The breather hose attachment that meets the front frame with a screw. It often than not breaks or the screw is loose
2 of us 200 owners have had a fair bit of vibration due to either a broken breather hose mount or a missing screw! It seems it vibrates on the metal giving noise and or vibration

 

[Baglady1990]

Doh 500 owners! (Autocorrect)

 

[John202020]

Do you have some "jump leads" ?
If you have, connect the black one to any decent metal part of the engine( make sure it's a good connection ) the other end to the battery NEGATIVE do your tests again?
Failed breather hoses can upset the idle.

 

[Baglady1990]

Do you have some "jump leads" ?
If you have, connect the black one to any decent metal part of the engine( make sure it's a good connection ) the other end to the battery NEGATIVE do your tests again?
Failed breather hoses can upset the idle.

Where does that thin breather hose from the air box go? I’ve actually not investigated myself and interested to know!

 

[puntodeltathema]

So I think we may have some confusion here between breather hoses (under the air cleaner) and the fresh air intake pipe/horn from the front of the engine bay into the air cleaner. The latter is pretty notorious in my experience for throwing up quite disproportionate vibrations if it's at all loose, at either end (though on 500s chances are the little hex head screw fixing the "open" end is rusted in solid). I think this is what baglady is referring to. Worth a check, and it's an easy fix. Here's hoping...good luck.

 

[Danoid]

I’ve looked at the intake and nice and solid.

Just out of interest can you see the YouTube video?

 

[puntodeltathema]

Ah yes I can see the video. Looks like spark or fuelling is just a bit marginal at idle and the ECU is intervening to keep it going. Difficult to diagnose from afar if no engine management errors are coming up, but check all HT leads are good and clicked on properly at both ends, and throttle body is clean and not too clogged up with oil (though some oiliness is normal and not an issue).

I wouldn't *think* it's the rear engine/gearbox mount but fairly easy to check if you don't mind getting on the ground and seeing how much slop there is. (You can generally move it but only a little bit).

All of that said the 1.2 with the Marelli injection is not known as the smoothest idler. (Marelli being the Italian equivalent of electrical supplier Joe Lucas - the prince of darkness!)

 

[John202020]

Where does that thin breather hose from the air box go? I’ve actually not investigated myself and interested to know!

Actually not sure, It runs down and under the intake manifold you can feel where it goes just not sure possibly crank case breather vs rocker cover breather( the thick one), ours was split when we got the car so had to replace it.

 

[Baglady1990]

I shall investigate ? give it the once over! Not looking for problems but the car is only getting older..... like it’s owner ??

 

[typecastboy]

I’ve had masses of problems with rough idle all documented on my Love 500 YouTube channel under Loopy Harold. 12 videos in total on that one car.

Initially MES said air seepage so i changed the inlet manifold and that made a massive difference to rough running. However the rough idle remained.

I changed everything! Here’s a list.

Inlet manifold, spark plugs twice, injectors, fuel rail, coil pack, throttle body, plug leads, cam sensor, cam solenoid, lock sensor, map sensor, everything else sensor. Whatever I did, the rough idle remained. Took it for mot and asked them to look and they sorted it in half an hour. They did an ECU reset of some sort and it worked. I had already done several resets myself but whatever they did worked.

However, from what you describe my money is on your earth lead.

Take a look at my video on common faults and you will see it in all its glory. Replacements are £4 on eBay.


https://youtu.be/ACbYHPb6Ons

 

[Rocco Reviews]

Hi,

When using electrics such as electric windows, turning heater controls on (non AC car), headlights etc the revs drop a bit, this is somewhat expected but there's a shudder/vibration feeling in the car which isn't normal.

Driving the car is absolutely fine and feels smooth, idling is smooth too just not when using electrics. However if I bring the revs up a bit then lower it shudders a little bit.

I'm on a Fiat 500 FB group and someone posted a video of their car doing the same, although mines not quite as bad.

https://youtu.be/z9UZbm1Hhss

Last year I changed the spark plugs as part of the routine maintenance and battery is only 2 years old, so it won't be them or very unlikely as I had the same issues before anyway (been a few years like this).

Is this looking more like an engine mount issues and more specificially the rear one?

Our 500 1 4 Pop shuddered a little but. Maybe a couple times in the past 7 years of it running, we've had it for 5 years now. But the car is 7 years old, and was very well maintained before we bought it. It has only shuddered twice. Once when it was cold, and it had a small misfire. And one other time where it went into a temporary limp mode. Both were fixed by a quick restart. I do know once the battery went flat, and the oil had drained out of the MultiAir system just a tiny bit for sitting for 3 weeks. The time the battery died it was sputtering, and I had to hold the revs at 2k so it wouldn't die on me. And when the oil drained from the MultiAir system, it sputtered for around 7 seconds. With the electrics off. With them on, it doesn't really do anything, except for maybe a tiny shudder, but you really have to be waiting for it. And now what it feels like. I would check the electrical contacts on the battery. And replace the earth lead if that doesn't work.